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De welopment of a Bona Fide Physical Maintenance
Standard for CF and DND
Fire Fighters
Contract #: 003SV.W8477-3-SC02
Principal Investigator: J.M. Qeakln, Ph.D.
Collaborative Investigators: R. Pelot, Ph.D., F?Eng. J.T. Smith, Ph.D. J.M. Stevenson, Ph.D. L.A. Wolfe, Ph.D.
DND Scientific Authority: Major (Ret’d) S.W. Lee, Ph.D.
Research Team: Captain S.F? Jaenen, M.Sc. S.A. Hughes, M.Sc. J.W. Dwyer, M.Sc. A.D. Hayes, M.Sc.
Ergonom~a Research Group Queen’s university K7ngslon, ontorfo
QUEEN’S UNIVERSITY ERGONOMICS RESEARCH GROUP
THE DEVELOPMENT OF A BONA FIDE PHYSICAL
MAINTENANCE STANDARD FOR CF AND DND FIRE FIGHTERS
Contract # 003SV.W8477-3-SC02
Principal Investigator: Janice M. Deakin, Ph.D.
Collaborative Investigators: R Pelot, Ph.D., P.Eng. J.T. Smith, Ph.D. J.M. Stevenson, Ph.D. L.A. Wolfe, Ph.D.
DND Scientific Authority: Major (Ret’d) S.W. Lee, Ph.D.
Research Team: Captain S.P. Jaenen, M.Sc. S.A. Hughes, M.Sc. J.W. Dwyer, M.Sc. A.D. Hayes, M.Sc.
Queen ‘s University, Kingston, Cd
ABSTRACT
The Queen’s Ergonomics Research Group (ERG) was contracted to assist DND in the development of a occupation-specific physical maintenance standard for CF and DND fire fighters in 1993. During the first phase of the research project the most demanding and representative tasks related to the occupation were identified by an expert panel and a continuous, ten item circuit was developed. The reliability and physical demands of the circuit were evaluated in a pilot study with 23 male CF fire fighters. Test-retest reliability was reported at r = 0.93 (pdO.005). The physiological assessment of the circuit supported subjective reports that the subjects had provided a maximal effort during the test trials.
The main data acquisition occurred during the summer of 1994. Data were collected on a total of 202 men (100 CF and 102 DND) and 24 women fire fighters. Time to completion on the circuit ranged from 502 to 18:05 across the entire sample. Data were analysed to address the effects of age, gender and aerobic fitness rating on circuit performance. As expected, the time to complete the circuit systematically increased for between gender comparisons, with increasing age, and for decreasing levels of fitness. Based on a number of impact analyses, the ERG has recommended the implementation of an 8:00 performance objective. The potential impact of this objective on the current cohort has led the ERG to recommend a three year period over which the standard would be implemented.
In light of the performance of female subjects within the main study, a substudy was undertaken to evaluate the performance characteristics of aerobically fit women (non- fire fighters) over a series’of training sessions. In the absence of changes in fitness levels, the women improved their mean completion times on the circuit from 852 to 6:56 over the eight training sessions. Although these data were not used in the development of a performance objective, they do provide evidence that women can successfully complete the circuit within the range of times that were under consideration as the performance objective.
A second substudy was conducted to investigate the mechanics of the forcible entry task. The results of this work indicated that the simulation reflected characteristics consistent with the actual task. The specific parameters assigned to the forcible entry task were successful in demanding an adequate level of effort and duration when compared with actual forcible entry tasks.
The following report represents the final phase of this contract. It contains the background information, research findings, and recommendations related to all phases of the project.
ii
ACKNOWLEDGEMENTS
The successful completion of a research project of this magnitude is always due to the significant contribution of a number of committed people. The fire fighting project is no exception. I would first like to acknowledge the commitment of Dr. Wayne Lee, and Captain Sue Jaenen of the Department of Physical Education, Recreation and Amenities (DPERA). As the on-site coordinator, and military liaison, Capt. Jaenen ensured that the data acquisition moved efficiently on each of the bases that served as test sites. The Canadian Forces Fire Marshall, (CFFM) LCol. (Ret’d) Gaetan Perron provided support, encouragement and enthusiasm throughout his term during the early phases of the project. The dedication by CFFM of Chief Warrant Officer Ken Hoffer to the project, was instrumental to its success. Chief Hoffer’s commitment to the work, his expertise and his patience while travelling with the research team enhanced the quality of the research process. The field testing occurred at the fire halls of CFB Borden, Chilliwack, Comox, Esquimalt, Downsview, Halifax, Kingston, North Bay, Petawawa and Uplands. The Fire Chiefs of each of these halls supported the research endeavour, and made us welcome during our stay at each base. Finally, I would like to extend our deepest gratitude to the men and women fire fighters who volunteered to act as subjects throughout all phases of this project. These people, many of whom came from other bases or civic fire departments, accepted our research mandate, and worked with us to provide adequate representation from the fire services.
The travelling research team, who spent approximately nine weeks moving across the country, did an outstanding job. In addition to Capt. Jaenen and Chief Hoffer, research assistants Woody Dwyer, Michael Fisher, Sean Hughes, Derek Kozar, Elaine Mullan, and Tara Vickers, carried out their duties with diligence and good humour through even the most difficult moments. A special thank you to my research associate April Hayes, who over the last twelve months, has spent countless hours working with us in the development of the final report. The collaborative investigators: Ron Pelot, Terry Smith, Joan Stevenson, and Larry Wolfe, all provided valuable insight and comments throughout the course of the project. Ron’s interest in the forcible entry simulation led to his development and supervision of the forcible entry substudy contained within this report.
The test of a truly functional team is in it’s ability to respond efficiently and effectively. The entire team assembled to carry out this contract performed beyond any reasonable
s. To all of you, congratulations and thank you.
Principal Investigator
. . . 111
EXECUTIVE SUMMARY
Physical fitness standards within the Canadian Forces (CF) have evolved
significantly during the past two decades. Prior to 1980, CF members were evaluated
annually by means of a 1.5 mile run, sit-ups, push-ups, and chin-ups. This annual test
had age and gender-based standards, and was derived from Cooper (1968) and
Astrand and Rhyming (1954). Due to the number of injuries and deaths associated with
the test, in 1980 the CF Surgeon General deemed the 1.5 mile run as unsafe for
personnel over the age of 30 years. In 1983, the CF adopted the Exercise Prescription
Plan (EXPRES), which was based on the Canadian Standardized Test of Fitness
(1981). The CF EXPRES utilized practical and safe evaluation procedures, and
provided personnel with a prescription of exercise which served as the basis for their
training programs.
Concurrent with the development of the CF EXPRES was the development of
Minimum Physical Fitness Standards (MPFS). These MPFS were based on five
common military tasks often performed in cases of emergency, and would be required
of all military personnel regardless of trade, classification, age or gender (Stevenson,
Andrew, Bryant, Thomson, Lee & Swan, 1988). Both the CF EXPRES and MPFS have
been accepted by the Chief of Defence Staff (Canadian Forces Administrative Order
(CFAO) 50-i) as the approved programs of the CF. MPFS is the minimum level of
fitness required by all CF personnel to permit them to meet the physical demands of the
five common tasks (Stevenson et al., 1988). Successfully meeting the MPFS,
iv
however, does not necessarily mean that one is fit to perform specific occupational
requirements (Singh, Lee, Wheeler, Chahal, Oseen & Courture, 1991; Lee, 1991).
While the CF EXPRES protocol will meet most needs, individuals or groups may
require other means of assessment to measure and demonstrate their operational
capability. Fire fighters are one such group.
Currently, the physical fitness level of CF fire fighters is evaluated bi-annually.
In the spring, all CF fire fighters are evaluated using the EXPRES protocol and must
meet the MPFS. In the fall, they are evaluated on a trade-specific test consisting of a
1.5 mile run, sit-ups, push-ups, chin-ups, victim carry and a balance task, and must
meet an established age/gender based standard (CFAO 50-23). In 1991, the Canadian
Forces Fire Marshall (CFFM) identified the CFAO 50-23 as both inadequate and
unsafe for fire fighters. Specific concerns about the current test included: 1) the
existence of differential standards for CF and DND fire fighters, although the job
requirements were identical; 2) the lack of scientific validation; and 3) whether the
test was an accurate indicator of operational capacity. The development of an
occupation-specific maintenance test reflecting actual job demands would ensure that
CF 8 DND fire fighters are physically capable of carrying out their duties. To that end,
the Canadian Forces Fire Marshall’s Office has requested that the current CFAO 50-
23/CPAO 9.21 fitness standards for trades of fire fighters be replaced with a new test
that complies with the Canadian Human Rights Act (1985) and which meets the bona
fide occupational requirements (BFOR) described in Section 15 of that Act.
V
A BFOR is a “condition of employment which is imposed in the sincere belief that
it is reasonably necessary for safe, efficient, and reliable performance of a job and
which is, objectively, reasonably necessary for such performance” (Government of
Canada, 1988). A BFOR involves three essential elements: quantification of the
essential components of the job, identification of the capabilities necessary for safe,
efficient, and reliable performance of these essential components, and the assessment
of an individual’s capabilities. The objective basis of a BFOR must consider existing
scientific data, empirical studies, expert opinion, the detailed nature of the duties to be
performed, and the conditions existing in the work place (Government of Canada,
1988).
To ident-j the most common and demanding fire fighting tasks, an extensive
review of the literature and task analysis (Appendices A and B) were conducted. The
Ergonomics Research Group at Queen’s University (ERG) then met with two panels of
subject matter experts from the Canadian Forces Fire Academy (CFFA), and the CFFM
in order to select the most demanding and representative tasks specific to CF fire
fighters. A circuit consisting of ten occupational tasks was developed. The reliability of
the circuit was assessed during a pilot study conducted at 7 Wing Ottawa in November,
1993, with 23 male CF fire fighters. During this study, the physiological demands of the
circuit were characterized, and significant correlations between circuit performance and
physiological measures were identified.
Following modifications to the circuit, the main data collection phase
commenced in April 1994. The ERG travelled to CFB Borden, Chilliwack, Comox,
vi
Esquimalt, Halifax, North Bay and Petawawa to collect data on CF and DND fire
fighters. Subjects volunteered to participate in the study, which included a medical
questionnaire, a step test to estimate maximal oxygen uptake (VOz max), and two trials
of the circuit, each in full turnout gear and self-contained breathing apparatus (SCBA).
Consecutive trials were one day apart to allow adequate recovery time. A total of 202
men (100 CF and 102 DND) and 24 women participated in this phase of the data
collection..
Two separate substudies were also undertaken as part of the research program.
The first evaluated the performance of a group of physically fit women (non-fire
fighters) on the circuit over eight sessions. The effects of task familiarity, in the
absence of changes in cardiovascular fitness were evaluated over the series of training
sessions. Results indicated that there was a statistically significant improvement in
performance over the practice sessions (mean improvement of 152). There were no
improvements in the subjects’ aerobic capacity as a result of repeated exposure to the
circuit.
The second substudy investigated the mechanics of the forcible entry task by
quantifying the performance characteristics of the simulation with similar measures
taken on an actual structure that could be encountered at a fire scene. Results of the
investigation indicated that tasks completed on the tire were equivalent to tasks
completed on the reinforced structure terms of physiological response, performance
measures, and perceived exertion and perceived similarities. The parameters
assigned to the simulated forcible entry test were also examined. It was determined
vii
that the most appropriate task parameters for the simulated forcible entry task were to
move the tire 30 cm using the 4.54 kg sledge hammer.
Following analyses of the sample of CF and DND fire fighters, ERG has
developed a single maintenance standard of 8:00, accompanied by a series of
recommendations related to the implementation of the standard. This report is a
synopsis of all the material related to the development of the occupational maintenance
standard and the recommendations for implementation.
. . . VIII
TABLE OF CONTENTS
Abstract ................................................ ii
Acknowledgements ........................................ iii
ExecutiveSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv
1.
2.
List of Figures ........................................... xv
List of Tables ............................................ xvi
List of Abbreviations ..................................... xvii
Statement of Work ......................................... 1
Review of the Literature .................................... 3
2.1 Occupational Selection and Maintenance Standards ............ 3
2.2 Physical Demands . Assessment of Maximum Oxygen Uptake .... 6
2.3 Assessment of Maximal Anaerobic Power .................... 9
2.4 Assessment of Fitness-Related Factors and Physical
Characteristics of Fire Fighters .......................... 10
2.5 Existing Screening Tests ... ! ............................ 14
2.6 CF Fire Fighter Physical Fitness Tests ...................... 16
2.7 Bona Fide Occupational Requirements ..................... 19
3. Circuit Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
ix
4. PilotStudy .............................................. 27
4.1 Purpose ........................................... ..2 7
4.2 Methods ............................................. 27
4.2.1 Subjects ...................................... 27
4.2.2 Pre-Screening .................................. 28
4.2.3 Preliminary Instructions ........................... 28
4.2.4 informed Consent ............................... 29
4.2.5 Testing Sessions ................................ 29
4.2.6 Laboratory Tests ................................ 29
4.2.7 FieldTests .................................... 31
4.3 Results and Discussion ................................. 33
4.3.1 Physical Characteristics of Subjects ................. 33
4.3.2 Indirect and Direct Measurements of Maximal
Oxygen Uptake ................................ 34
4.3.3 Maximum Anaerobic Power. ....................... 35
4.3.4 Field Tests .................................... 36
4.3.4.1 Heart Rate .............................. 36
4.3.4.2 Ratings of Perceived Exertion ............... 38
4.3.4.3 Post-Circuit Performance Lactates ........... 38
4.3.4.4 Circuit Completion Times .................. 38
4.3.5 Correlation of Test Variables ...................... 39
X
4.3.6 Circuit Test-Retest Reliability ...................... 41
4.4 Conclusion ......................................... ..4 3
5. Main Data Collection Phase: Development of a Physical Maintenance Standard for CF and DND Fire Fighters . . . . . . . . . . . 44
5.1 Purpose ........................ ..................... 44
5.2 Methods ........................................... ..4 5
52.1 Subjects ...................................... 45
5.2.2 Pre-Screening .................................. 45
5.2.3 Instructions to Subjects ........................... 45
5.2.4 Informed Consent ............................... 46
5.2.5 Testing Sessions ................................ 46
5.2.6 Circuit Performance ............................. 46
5.3 Results ............................................ ..4 8
5.3.1 Descriptive Statistics ............................. 48
5.3.2 Indirect Measures of Maximal Oxygen Uptake ......... 49
5.3.3 Circuit Completion Times ......................... 50
5.3.4. Impact Analyses ................................ 51
5.4 Discussion ............................................ 56
xi
6. Women’sSubstudy ....................................... 59
6.1 Purpose ........................................... ..5 9
6.2 Methods ........................................... ..5 9
6.2.1 Subjects ...................................... 59
6.2.2 Orientation .................................... 60
6.2.3 Testing Sessions ................................ 60
6.2.4 Laboratory Tests ................................ 61
6.2.5 Field Test ..................................... 62
6.3 Results ........... . ................................ ..6 3
6.3.1 Maximum Oxygen Uptake ......................... 65
6.3.2 Total Circuit Time ................................ 65
6.3.3 Individual Test Items ............................. 66
6.3.4 Air Consumption During the Circuit Sessions .......... 67
6.3.5 Maximum Heart Rate ............................. 67
6.4 Discussion ......................................... ..6 7
6.4.1 Total Circuit Time ............................... 68
xii
7. Forcible Entry Wbstudy ................................... 71
7.1 lntioduction ........................................... 71
7.2 Methods ........................................... ..7 3
7.2.1 Subjects ...................................... 73
7.2.2 Experimental Setups ............................. 73
7.2.3 Experimental Procedures ......................... 74
7.2.4 Protocol ....................................... 76
7.2.5 Data Collection ................................. 77
7.2.6 Data Reduction and Analysis ...................... 81
7.3 Results ............................................ ..8 2
7.3.1 Test of Normality ................................ 83
7.3.2 Questionnaire Analysis ........................... 86
7.4 Discussion ........................................... 88
7.4.1 Objective 1 .................................... 88
7.4.1.1 Differences between hitting the
tire and hitting the reinforced structure ........ 88
7.4.2 Objective2 .................................... 90
7.4.2.1 Hammer effect ............................ 92
7.4.3 Comparison to previous research ................... 93
7.5 Conclusion ........................................... .
. . . XIII
8. Recommendations ........................................ 95
8.1 Introduction ........................................... 95
8.2 Determination of Performance Objective .................... 95
8.3 Implementation Schedule ................................ 96
8.4 Testing Schedule and Protocol ............................ 97
8.5 Remedial Assistance ................................... 98
8.6 Retest ............................................... 99
8.7 Sanctions ............................................ 99
8.8 Incentives ............................................ 99
9. Literature Cited , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix A: Most Common and Demanding Tasks
of CF Fire Fighters . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . 108
Appendix B: Catalogue of Fire Fighting Equipment ............... 111
Appendix C: Preliminary Instructions to Subjects ................ 115
Appendix D: Informed Consent Forms ......................... 116
Appendix E: Health Appraisal Questionnaire .................... 119
xiv
LIST OF FIGURES
1.
2.
3.
4.
5.
6.
7.
8.
9.
IO.
II.
Model for the development of a bona fide physical
maintenance standard.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Schematic of the circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Average heart rates for tasks on the circuit;
Day 1 vs. Day2 (pilot study) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Kaplin-Meier Curve with 95% confidence bands
(Circuit completion times) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Impact of three performance objectives on gender . . . . . . . . . . . . . . . . 54
Impact of performance objectives as a function of age category . . . . . . 55
Impact of performance objectives on service . . . . . . . . . . . . . . . . . . . . . 56
Mean total time on circuit (& standard error) (women’s substudy) . . . . . 66
Front view of the photoelectric switch setup to collect
speed measures for the forcible entry substudy . . . . . . . . . . . . . 79
A subject’s heart rate profile during the testing procedure,
highlighting the peak heart rate value (forcible entry substudy) . 80
A graphical representation of the summarized questionnaire data for
all the tasks and each topic area (forcible entry substudy) . . . . . 87
xv
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
LIST OF TABLES
Recommended minimum v/O2 max for fire fighters .................. 8
Physical characteristics of fire fighters ......................... 11
Percentage of fire fighters above proposed minimum values
and exceeding selected clinical criteria ................... 13
CF fire fightei standards for 1.5 mile run ........................ 17
Physical characteristics of subjects (pilot study) .................. 34
Circuit performance times (pilot study) ......................... 39
Pearson product moment correlation coefficients (pilot study) ....... 40
Correlations measuring the reliability of four performance
measures for individual tasks comprising
the circuit (pilot study) ... ., ............................. 42
Age distribution of subjects by gender and service ................ 48
Mean predicted VO, max (ml/kg/min) f standard deviation
by gender, service, and age category ..................... 49
Mean circuit performance times (min:sec) by fitness rating .......... 50
Circuit completion times (min:sec) by gender, age
and service .................................. 51
Summary of testing sessions (women’s substudy) ................ 60
Subject characteristics (women’s substudy) ..................... 64
Results of strength tests (women’s substudy) .................... 65
Summary of the parameters for the eight tasks used
in the forcible entry substudy ........................... 75
Normality of the data (forcible entry substudy) ................... 83
Mean performance data on the forcible entry task. ................ 84
ANOVA and the Day Effect (forcible entry substudy) . . . . . . . . . . . . . . 85
Summary of Duncan’s Multiple Range Test (forcible entry substudy) . . 86
Friedman’s Non Parametric ANOVA for the questionnaire data
(forcible entry substudy) . . ., . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
xvi
BFOR BMI CF CFMPFS CFAO CFB CFFA CFFM CHD CSTF DCIEM DND DPERA EKG ERG HR HLI H&i4 HRR MP0 OBLA OPSS PD PPO RPE SCBA Lni V02 max WHR
Units:
bw beats per minute cm centimetre m metre ml millilitre I litre _
Analogue to digital Bona fide Occupational Requirement Body mass index Canadian Forces Canadian Forces Minimum Physical Fitness Standards Canadian Forces Administrative Order Canadian Forces Base Canadian Forces Fire Academy Canadian Forces Fire Marshall Coronary heart disease Canadian Standardized Test of Fitness Defence and Civil Institute for Environmental Medicine Department of National Defence Directorate of Physical Education, Recreation, and Amenities Electrocardiogram Ergonomics Research Group at Queen’s University Heart rate Average heart rate Maximum heart rate Heart rate reserve Mean power output Onset of blood lactate accumulation Occupational Physical Selection Standards Power decline Peak power output Rating of perceived exertion (Borg Scale) Self-contained breathing apparatus Ventilatory threshold Maximal oxygen uptake Waist-to-hip ratio
psi kg N W
pounds per square inch kilogram Newton watt
xvii
Chapter I:
STATEMENT OF WORK
Queen’s University’s Ergonomics Research Group (ERG) has played a
significant role, through earlier contracts with DPERA and DCIEM, in developing
physical fitness standards that must be attained in order to remain in the Canadian
Forces (CFMPFS). The ERG was also involved in the research project for the
assessment of occupational physical selection standards (OPSS). The goal of this
research project was to develop valid, reliable minimum physical fitness standards for
Canadian Forces (CF) fire fighters. The development of these occupational physical
standards was to include the following:
a. Conduct a review of tne literature, including previous research, task
protocols, existing standards, and military and civilian reports, relating to
the development and application of physical fitness standards for fire
fighters.
b. Visit civilian and military testing facilities for fire fighters to assist in the
documentation of the operational aspects, reliability and validity of some
scientific approaches to physical fitness tests that are currently in place.
C. Conduct preliminary task analyses of fire fighting work and identify the
d.
physical demands of the occupational tasks.
Develop and validate a circuit that simulates representative fire fighting
tasks, including some of the most demanding aspects of fire fighting.
1
e.
f.
Q-
h.
I.
i-
k.
Determine the reliability of the individual task items and the circuit.
Validate the circuit against appropriate tests of maximum aerobic and
anaerobic work power.
Determine the relationship of the circuit to other performance and health
related fitness tests that are currently administered to DND and CF fire
fighters.
Characterize the physiological demands of the circuit on a homogeneous
sample of the fire fighting population.
Evaluate the effects of aerobic fitness, age and gender on circuit
performance across all segments of DND and CF fire fighters.
Evaluate the impact of a range of potential standards on the current fire
fighter population.
Recommend a standard of performance for members of DND and CF fire
fighting personnel, in conjunction with DPERA.
Chapter 2:
REVIEW OF THE LITERATURE
. . 7 1 Occupational Selection and Manlmnce Skmdavls
It is widely accepted that fire fighting is one of the most physically demanding
and hazardous civilian occupations (Bahrke, 1982; Brownlie, Brown, Diewert, Good,
Holman, Laue & Banister, 1985; Ben-Ezra & Verstraete, 1988; Davis, Dotson & Santa
Maria, 1982; Faria & Faria, 1991; Gledhill & Jamnik, 1992a; Green & Crouse, 1991;
Guidotti, 1992; Hilyer, Brown, Sirles & Peoples, 1990). In view of the strenuous nature
of fire fighting tasks and the importance of public and fire fighter safety, it is essential
that fire fighters have the physical capabilities to meet the demands of the job. The
development of appropriate standards could do much to upgrade the ability of fire
fighters to fulfil their job mandate while at the same time addressing the issues of
occupational health, safety, and productivity (Hughes, Ratliff, Purswell & Hadwiger,
1989). The incidence of accidents and injuries is also reduced and job performance is
increased when fire fighters meet established standards of fitness (Adams, Yanowitz,
Chandler, Specht, Lockwood 8 Yeh, 1986; Cady, Thomas & Karwasky, 1985). In order
to set fitness standards, numerous researchers have attempted to characterize the
physiological demands of fire fighting (Brownlie et al., 1985; Considine, Misner,
Boileau, Pounian, Cole & Abbatiello, 1976; Davis & Dotson, 1987; Davis et al., 1982;
Gledhill & Jamnik, 1992b; Misner, Boileau & Plowman, 1989; Schonfeld, Doerr &
Convertino, 1990; Windle, 1975).
Fire fighting requires the integration of numerous physical capabilities and
mental skills in order to perform the essential tasks safely and effectively. The
demands of fire fighting tasks require the fire fighter to possess very high levels of
muscular strength and endurance, aerobic and anaerobic power and motor abilities
such as agility, manual dexterity, balance and flexibility (Gledhill & Jamnik, 1992a).
Hand-eye coordination and total body speed are also important (Considine et al.,
1976). Fire fighters must be able to execute numerous tasks. Of these tasks, victim
rescue is cited most frequently as being both the most important and demanding
(Romet & Frim, 1987). Due to the intermittent nature of fire fighting, fire fighters must
have the physical capacity to complete demanding tasks at irregular intervals
separated by periods of less demanding work or rest. Furthermore, a series of such
tasks must be performed under extreme environmental conditions while wearing heavy
and restrictive equipment (Sothmann, Saupe, Jasenof, Blaney, Fuhrman, Woulfe,
Raven, Pawelczyk, Dotson, Landy, Smith & Davis, 1990; Rogers, 1984; Gilman &
Davis, 1993).
The working environment of fire fighters may also expose them to extreme
temperatures, poor air quality and high noise levels, thereby increasing job demands.
Noise levels during fire fighting almost always exceed the limits set by the U.S.
Occupational Safety and Health Administration (Reischl, Bair & Reischl, 1979).
Hearing protection devices are generally not worn, because a fire fighter must be able
to hear a screaming victim and communicate with other fire fighters. Fire fighters must
also operate loud equipment for extended periods of time (Davis & Dotson, 1987)
4
which may lead to hearing loss and adverse cardiovascular effects (Reischl et al.,
1979).
Hazardous gases, particularly those from the thermal degradation of plastics,
are produced in fires. The self-contained breathing apparatus (SCBA) protects a fire
fighter from harmful gases as long as a seal exists around the nose and mouth, and the
removal of the mask can leave the fire fighter vulnerable to toxic levels of air pollutants
(Davis & Dotson, 1987). Carbon monoxide levels as high as 3000 ppm have been
measured in a fire, and toxic levels of carboxyhemoglobin which may cause temporary
or permanent paralysis, blindness, muscular spasms or twitching may be the result of
exposure (Thomas, 1993). Additionally, smoking cigarettes and carbon monoxide
exposure interact in an additive fashion to lower dynamic pulmonary function (Horsfield,
Guyatt, Cooper, Buckman & Cumming, 1988). The most likely period of exposure to
carbon monoxide occurs during the overhaul or cleanup portion of interior fires since
fire fighters are more likely to remove their SCBA at that time (Radford & Levine, 1976).
Fire fighters may also be exposed to high temperatures inside a building after
experiencing freezing winter temperatures outside. Inside a burning structure,
temperatures can reach 232°C (Gilman & Davis, 1993) and fire fighters have been
severely burned despite wearing protective clothing (Davis & Dotson, 1987). While
protective clothing is designed to keep heat and fire away from a fire fighter, it also
limits the dissipation of body heat generated during physical work, thus creating a
secondary heat environment. This impermeability prevents the evaporation of sweat
(Skoldstrom, 1987) and excessive sweating can lead to plasma volume loss in excess
5
of 10% (Davis & Dotson, 1987). Failure to provide proper hydration could result in
accelerated fatigue, heat exhaustion and heat stroke (Davis & Dotson, 1987).
Protective equipment may also limit a fire fighter’s performance. Standard
protective clothing and equipment may elevate the energy cost of moderate work by
approximately 33% over that required to perform the same work without protective
clothing and equipment (Davis et al., 1982). The SCBA is also estimated to reduce
maximal performance by 20% (Raven, Davis, Shafer & Linnebur, 1977) and increase
oxygen uptake by 0.54 Vmin (Louhevaara, Smolander, Tuomi, Korhonen & Jaakkola,
1985). This is due to both the additional mass of the SCBA and related increases in
respiratory airway resistance.
Numerous researchers have attempted to quantify the physical and physiological
demands of fire fighting in order to set fitness standards. Maximal aerobic capacity
(VO, max) has been consistently identified as one of the most important physiological
determinants of performance (Gledhill & Jamnik, 1992a; Davis & Dotson, 1987; Misner,
Plowman & Boileau, 1987; Lemon & Hermiston, 1977). V02 max can be measured in a
laboratory by assessing gas exchange (direct method), or can be predicted from pulse
rate or other physiological variables during submaximal exercise. Factors such as
body composition, gender, age, mode of exercise used to determine VOz max, and
present training level influence VOz max values (Astrand & Rodahl, 1986; McArdle,
Katch & Katch, 1991; Thoden, 1991). Treadmill and cycle ergometry are the two most-
commonly used modes of exercise for maximal testing (Astrand & Rodahl, 1986;
6
Thoden, 1991). Testing protocols using a cycle ergometer result in lower VOz max
values than testing protocols using a treadmill (Astrand & Rodahl, 1986). If a true VOz
max is to be attained, large muscles must be used (Lamb, 1984) and the subject
should be evaluated in an upright position (Astrand & Rodahl, 1986).
Direct methods of measuring V02 max may not be feasible due to equipment
costs and the level of technical expertise required to conduct the test. Further,
physician supervision is recommended for maximal tests administered on healthy men
and women older than 40 and 50 years respectively, whereas physician supervision is
not required for submaximal tests (ACSM, 1991). In contrast, submaximal tests are
usually easy to administer and interpret, and require little equipment or technical
expertise to conduct. Submaximal step, cycle and treadmill tests have been validated
by studying the correlation between measured and estimated VOz max determined from
heart rate responses to submaximal exercise (ACSM, 1991; Astrand & Rhyming, 1954;
Dotson & Caprarola, 1984; Jette, Campbell, Mongeon & Routhier, 1976). Monitoring
heart rate to predict VOz max is based upon the linear relationship between V02 and
heart rate during submaximal work (Astrand & Rodahl, 1986). Other field tests such as
the 12 minute run, the 1.5 mile run, and other running distances have been validated by
studying the correlation between directly measured VOz max and test performance
(Cooper, 1968; Margaria, Aghemo & Limas, 1975; Myles, Brown & Pope, 1980; Rasch
8 Wilson, 1964). As with any prediction inherent errors associated with each test must
be acknowledged.
7
Many studies have been undertaken to determine the minimum v/O2 max
required to perform fire fighting tasks. Gledhill and Jamnik (1992a) measured VO, max
during fire fighting operations via the open-circuit technique and reported a value of 45
ml/kg/min as the minimum acceptable requirement for fire fighters. Lemon and
Henniston (1977) collected and analyzed expired gas volumes to assess the energy
costs of four selected isolated fire fighting tasks and reported a minimum requirement
of 39 ml/kg/min. Similarly, in a study to determine the energy requirement of simulated
stair climbing, O’Connell, Thomas, Cady, and Karwasky (1986) measured VOZ max
directly and recommended a minimum cut off of 39 ml/kg/min. In a study of 100 fire
fighters completing five tasks, Davis et al. (1982) determined V02 max by measurement
of the amount of 0, in the breathing apparatus before and after circuit performance and
recommended minimum scores for adequate job performance. These minimum
recommended values are summarized in Table 1.
Table 1: Recommended minimum VOz max for fire fighters
RELATIVE
I
ABSOLUTE INVESTIGATORS VALUE VALUE (I/min)
Lemon & Hermiston, 1977
O’Connell et al., 1986
Davis & Dotson, 1978
Gledhill & Jamnik, 1992a
39
39 2.71
42
45 4
8
3 3 Assessment of Maximum Anaerobic Pow .
To characterize the physical demands associated with fire fighting, Gledhill and
Jamnik (1992a) collected blood samples for lactate analyses 5 minutes after fire
fighters performed selected fire fighting tasks, and found peak lactate concentrations of
6 to 13.2 mM/I, indicating substantial involvement of the anaerobic system. After
maximal exercise, the blood lactate concentration in trained men between the ages of
20 and 40 years is between 11 to 14 mM/I, but may exceed 20 mM/I (Astrand & Rodahl,
1986). During submaximal work, a trained person produces less lactic acid than an
untrained person. At maximal workloads, however, a physically fit individual can
produce and tolerate greater amounts of lactic acid. This greater peak blood lactate
concentration during maximal work may be associated with the trained individual’s
ability to store greater amounts of muscle glycogen and to tolerate increased levels of
lactic acid (Lamb, 1984). The critical intensity at which the increase in lactate occurs is
defined as the onset of blood lactate accumulation (OBtA) (Thoden, 1991). In
untrained individuals, blood lactate begins to accumulate at 5060% of their VOz max,
while in trained individuals, blood lactate begins to accumulate at 80-85% or higher of
their v/O2 max (Astrand & Rodahl, 1986; Lamb, 1984; McArdle et al., 1991).
Sothmann, Saupe, Raven, Pawelczyk, Davis, Dotson, Landy, and Siliunas
(1991) found that fire fighters worked, on average, at 73% of their VO, max. However,
the range varied from 54 to 88%. This is consistent with the findings of Lemon and
Hermiston (1977) who observed that fire fighters worked at 60 to 80% of their v/O2 max.
As fatigue is associated with high levels of blood and muscle lactate, OBLA reflects the
9
ability to perform prolonged high intensity work. Thus OBIA is important to fire
fighters, since an individual with a higher OBlA can work at a higher intensity without
becoming fatigued. Astrand and Rodahl (1986) stated that well-trained subjects can
work for hours at 70 to 80% of their VOz max with little or no accumulation of blood
lactate. However, it ‘is questionable whether or not fire fighters can be considered well
trained subjects, as Horowitz and Montgomery (1993) found that the predicted VOz max
of 1,303 Canadian male fire fighters between the ages of 30 and 59 years were
significantly lower than the average Canadian (50th percentile of CSTF) of similar age.
. . . . 24 Assessment of Fitness Related Facto s and Phvsrcal Cwtertstrcs of Fm r
Fiahters
Fire fighting operations also require very high strength (Doolittle, 1979, cited in
Gledhill & Jamnik 1992a; Lemon & Hermiston, 1977). Fire fighters must lift, carry,
push, pull, hoist and drag equipment weighing up to approximately 50 kg and victims
weighing in excess of 100 kg. Upper and lower body strength have been identified as
important factors in job performance and in reducing the frequency of injuries (Cady,
Bischoff, O’Connell, Thomas, & Allan, 1979). Muscular endurance is equally important
since fire fighting involves prolonged strenuous work. Several studies have examined
the physical fitness of fire fighters using relatively small sample sizes. Table 2 provides
a summary of the physical fitness profile of fire fighters. These reports characterize fire
fighters as having similar fitness to a normal sedentary population of the same age.
10
Table 2: Physical characteristics of fire fighters
1977
Byrd& 52 34.6 182.0 83.8 20.7 34.0 64.0 137 a4 Collins,
1980 JJ 1: sbp - systolic blood pressure 2: dbp - diastolic blood pressure
(Reprinted from Byrd & Collins, 1980)
In a recent study (Horowitz & Montgomery, 1993), 1,303 male fire fighters aged
19-59 were assessed using the Canadian Standardized Test of Fitness (Fitness and
Amateur Sport, 1986). This study reported that fire fighters aged 30-59 years had
significantly lower VO, max (ml/kg/min) values than the average Canadian and that all
fire fighters were above average for sit-ups, push-ups and flexibility, measured by the
sit-and-reach test. Subjects were significantly heavier than the 50th percentile for
Canadian men of similar age. The three older groups (30-59 years) had body mass
index (BMI) and waist-to-hip ratio values that placed them in the health risk zone
according to morbidity and mortality data and had a significantly higher subcutaneous
body fat than the population of men of similar ages (Fitness and Amateur Sport, 1986).
Excess body fat significantly limits work performance and has a negative
influence on the ability to perform tasks which are weight-dependent (Davis et al.,
1982). Increased adiposity contributes to decrements in performance which occur with
advancing age, reduces heat tolerance, and increases the risk of coronary heart
11
disease, diabetes, orthopaedic injuries, and numerous other health problems. It has
been estimated that maintaining the appropriate body composition can enhance V02
max(ml/kg/min) and other dynamic measures of muscular fitness in the over-40 age
group by as much as 30% (Davis & Starck, 1992).
Saupe, Sottimann and Jasenof (1991) concluded that fire fighters tend to be
slightly taller, heavier and have higher mean values for BMI, the waist-to-hip ratio and
the sum of four skinfolds than the average for their respective age groups. These
effects were most pronounced for fire fighters over 40 years of age. These declines
are not necessarily age-dependent because a well trained 60 year old can be in
superior physical fitness than a relatively sedentary 30 year old (Saupe et al., 1991).
Table 3 illustrates the trend for age-associated changes in the physical
characteristics of fire fighters. It demonstrates the decreases with advancing age in
V02 max and increases in body fat, a greater incidence of mild to moderate
hypertension and pulmonary impairment, as well as the increased incidence of positive
exercise stress tests for coronary artery disease.
12
Table 3: Percentage of tire fighters above proposed minimum values for VOl max and exceeding selected clinical criteria
9 Proposed 20-25 yrs 30-35 yrs 40-45 yrs 50-55 yrs 60-65 yrs
Values
3.0 Vmin 83 73 27 33 3
42 ml/kg/min 87 20 3 0 0
39 ml/kg/min 93 40 13 3 3
33.5 100 83 33 17 7 ml/kg/min
Clinical 20-25 yrs 30-35 yrs 40-45 yrs 50-55 yrs 60-65 yrs Criteria
> 25% Body 0 27 60 83 77 Fat
Borderline to 20 33 53 70 73 Moderate
Hypertension
Positive 0 0 7 10 40 Exercise
Stress Test
Mild to 10 13 30 23 53 Moderate Pulmonary Impairment
N = 30 in all groups (Reprinted from Saupe et al., 1991)
The fire fighting population displays all of the major risk factors for coronary
heart disease (CHD): hypertension, obesity, smoking, family history of CHD, and a
sedentary lifestyle. They also have both a higher incidence of heart disease and a
higher premature death rate than persons in other high risk occupations (Barnard,
Gardner & Disco, 1976). Coronary heart disease in the United States has reached
epidemic proportions, but its prevalence among fire fighters constitutes a “super
13
epidemic” (Davalos, 1972, p.41). Fire fighters also suffer from the same injuries and
diseases as the population but are more prone to lower back and knee injuries, muscle
strains, heatstroke and pulmonary dysfunction or disease.
. . . 25 Exlstlna Screenlna Tests
Task analysis has been used to identify the important physical elements
necessary for fire fighting. These include dynamic strength, static strength, agility, total
body coordination, cardiorespiratory endurance, muscular endurance, eye-hand
coordination and total body speed (Considine et al., 1976). These elements can be
assessed individually with various physical fitness tests and are important in tasks
related to fire fighting, but attempts to characterize and quantify the physical elements
have been largely inadequate. Individual measurements lose their predictive power
because “on the job’ tasks rarely demand the performance of one physical component
at the mutual exclusion of the others, because actual fire fighting is interactive with
regard to these physical elements. Statistical correlations fail to support the prediction
of functional fire fighter task performance from performance on traditional physical
fitness tests (Misner et alJ989). No more than 33% of the common variance can be
explained between the actual task tests and physical fitness tests (Considine et al.,
1976).
Due to the intermittent nature of fire fighting, and the wide range of tasks that a
fire fighter must be able to complete at the scene of a fire, numerous researchers have
developed circuits of simulated fire fighting tasks to assess the physical abilities of fire
fighters (Davis et al., 1982; Schonfeld et al., 1990; Windle, 1975). Fire fighters at the
14
Kennedy Space Center are evaluated on a three-item Combat Task Test (CIT)
consisting of a stair climb, chopping simulation, and a victim drag. The CTT is
performed sequentially in standard fire fighter turnout gear and SCBA. The mean time
to complete the three tasks was 3.61 min (Schonfeld et al., 1990).
As part of the recruit selection process for the Albuquerque Fire Department, a
circuit consisting of pull-ups, an aerial ladder climb, a hose pull, charged hose drag,
hose carry, wall scale, and ladder lower and raise has been incorporated. A pass/fail
criterion has been established for each evolution, and there is a five minute rest
interval between evolutions. Failure of any part of the test disqualifies the applicant
and the test is terminated at that time (Windle, 1975). Davis et al. (1982) developed a
circuit consisting of a ladder extension, standpipe carry, hose pull, simulated rescue,
and simulated forcible entry, which are performed sequentially as quickly as possible,
while wearing full turnout gear and an SCBA. In a study of 100 professional fire
fighters, the mean time to complete the five simulated tasks was 7.0 min (Davis et al.,
1982).
Numerous task-based circuits are being used for fire fighter selection and
maintenance purposes (Windle, 1975; Wilmore, Parr, Girandola, Ward, Vodak,
Barstow, Pipes, Romero & Leslie, 1978; Davis et al., 1982; Schonfeld et al., 1990;
Sothmann, Landy & Saupe, 1992). The goal of a maintenance test is to ensure that a
fire fighter remains physically able to perform required work, whereas a selection test
may be designed to assess knowledge, skills and abilities in addition to the physical
requirements. Maintenance tests may be based on “acceptable” levels of performance
15
while selection tests may push the limits. Additionally, maintenance tests do not have a
goal of ranking candidates while a selection test might. A fair and appropriate
maintenance test is important for the safety of both the fire fighter and the public.
Conventional approaches for developing employment tests involve validation
studies to identify the critical elements of the job (Jamnik & Gledhill, 1992b). Test items
are then selected to include frequent or critical tasks necessary for successful
performance. In an occupation such as fire fighting, it is impossible to redesign the job
tasks in order to accommodate the capacities of the workers. Therefore, task-simulated
testing is appropriate for screening fire fighters and has been used frequently for
testing of applicants for other public safety occupations (Sothmann et al., 1992).
Evaluation procedures are often pilot-tested on experienced workers and their
feedback is used to validate and refine the test. Physiological responses can also be
measured on the job and during the test in order to demonstrate that responses are
similar (Jamnik & Gledhill, 1992a; Windle, 1975). Task-based circuit tests created in
such a fashion will generally meet human rights standards.
3 6 CF Fire F .
iahter Phvslcal Fitness Te&
During the third quarter of each year, all CF fire fighters are evaluated on a trade
specific test consisting of a 1.5 mile run, sit-ups, push-ups, chin-ups, victim carry and a
balance task and must pass an established age/gender standard (CFAO 50-23). The
standards for the 1.5 mile run are summarized in Table 4. Failure to achieve the
established standard results in compulsory remedial physical training for the fire fighter, .
with possible career sanctions.
16
Table 4: CF fire fighter standards for 1.5 mile run
In a study of 32 young CF male soldiers, the times for the 1.5 mile run correlated
well (r=-0.88, p ~0.01) with VO, max measured during treadmill running (Myles et al.,
1980) although the performance time of CF fire fighters completing the 1.5 mile run
has never been correlated to measured V02 max. Further, it is interesting to note that
in 1980, the Surgeon General declared the 1.5 mile run as unsafe for personnel over
the age of 30 years. This resulted in the cancellation of the 1.5 mile run as a measure
of cardiorespiratory fitness for the general CF population. Regardless, the 1.5 mile run
is still being used to assess the cardiorespiratory fitness of personnel in some
specialized trades or classifications.
In response to the cancellation of the 1.5 ,mile run as a general test of
cardiorespiratory fitness for CF personnel, the CF adopted the EXPRES test (1983)
which is based on the First Edition of the Canadian Standardized Test of Fitness
17
(CSTF) (Fitness and Amateur Sport, 1981). During the cardiorespiratory evaluation
component of the EXPRES test battery, VOz max is predicted from heart rate response
to a progressive submaximal step test (Jette, 1979; Jette et al., 1976). In a study of
118 CF male personnel, Bell and Allen (1983) found that the VOz max of the youngest
age group (17-29 years) was over-predicted by the step test while the VOp max of the
older age group (4049 years) was under-predicted by the step test when compared to
direct measurements during exhaustive treadmill running. Bell and Jacobs (1986)
determined that the mean predicted VOz max from the step test was significantly higher
than the mean V02 max measured directly during an exhaustive cycle test.
Limitations to the step test are well documented. After the stepping stages, the
heart rate is taken for a IO second count and multiplied by 6 to obtain the number of
beats per minute. Any inaccuracy in counting heart beats will distort the calculated
prediction of VO, max, which utilizes a regression equation. Second, the test was
developed using a large population and the regression equation used for the prediction
of v/O2 max may not be applicable to certain individuals or groups (Jet& 1979; Jette et
al., 1976; Shephard, Cox, Corey, & Smyth, 1979). Specifically, the regression equation
may underestimate the V02 max for fit and heavy participants, and overestimate the
VOZ max for unfit participants (Fitness and Amateur Sport, 1986). Notwithstanding the
limitations of the step test, the relationship between the predicted and measured VOz
max has not been examined in CF fire fighters.
18
. . 2.7 Rona Fide Occupational Recwemetds
The Canadian Human Rights Act (1985) prohibits discriminatory policies and
practices in matters related to employment, but it does provide an exception in
paragraph 14(a). This exception states that “it is not a discriminatory practice to refuse,
exclude, expulse, suspend, limit, specify or prefer in relation to any employment if the
employer establishes the practice to be based on a bona fide occupational requirement
(BFOR)” (Government of Canada, 1985). The Act, as well as the BFOR policy
statement, do not attempt to set specific rules, although the latter does identify criteria
which are to be applied consistently to the facts of each particular case. It must be
emphasized that the Canadian Human Rights Act has been enacted for the benefit of
the public. It should therefore be given an unprejudiced and broad interpretation and a
BFOR should be created so as to avoid discrimination.
A BFOR “is a condition of employment which is imposed in the sincere belief that
it is reasonably necessary for safe, efficient, and reliable performance of the job and
which is, objectively, reasonably necessary for such performance“ (Government of
Canada, 1988). There are three key elements that must be present for a BFOR to
exist. The employer must: 1) define the essential components of the job, 2) determine
the capacities necessary for safe, efficient and reliable performance of these essential
components, and 3) be able to assess whether or not an individual possesses such
capacities. Conditions of employment must be determined impartially and created with
an objective basis.
19
The objective approach must consider existing scientific data, empirical data,
expert opinion, the detailed nature of the duties to be performed and the conditions
existing in the work place (Government of Canada, 1982, 1988). A BFOR must relate
to essential components of the job. Furthermore, the capacity to perform the job in
existing work place conditions is not a BFOR if any of the conditions can be modified.
Thus, a BFOR is not a static condition but can vary over time with changing
technological circumstances. Employers are therefore obligated to continually update
and re-evaluate any BFOR.
Execution of the job in a specific manner is not considered a BFOR if the job can
be performed differently without undue hardship to the employer. A health or safety
risk can constitute a BFOR depending upon both the likelihood of the illness or injury
and the potential damage or injury which could result. The health or safety risk which is
to be given the greatest weight is risk to others, meaning the public or co-workers.
Employers should expect an employee to perform consistently under all
circumstances reasonably likely to occur on the job. Individuals may accept risk to self
but have the right to be informed of all such risks. Moreover, these risks must be
justified by the employer. If these criteria are met, then risk to self is not a legitimate
basis for a BFOR. The only way personal risk can be considered a valid BFOR is if the
risk is undue or if the individual is incapable of understanding the risks and the
likelihood of their occurrence.
An assessment of an employee’s capacity to perform the essential components
of the job may include oral questions and interviews, written test, functional tests,
20
training programs, probationary periods, medical examinations or investigations of a
candidate’s status with respect to national security or similar requirements
(Government of Canada, 1988). A decision concerning an individual’s capability of
proper performance must be made on the basis of a relevant and valid individual
assessment. Such an assessment is defined as one which accurately tests the
capacities necessary to perform the job safely, efficiently and reliably. A valid
assessment measures what it is intended to measure, is reliable because it consistently
gives the same results and is both accurate and precise. In order to ensure that
assessment procedures are not given on a selective and discriminatory basis, they
should be administered to all the employees affected by it.
21
Chapter 3:
CIRCUIT DEVELOPMENT
Circuit development and testing followed the model presented in Figure 1. An
extensive review of the literature was conducted to identify the most common and
demanding tasks encountered by fire fighters in both civilian and military settings. The
CF Fire Fighter Trade Specifications were reviewed in order to identify any additional
tasks that might be specific to CF and DND fire fighters. A list of these tasks was
compiled, and is attached as Appendix A. This list was presented to a panel of fire
fighter instructors at CFFA (Canadian Forces Fire Academy), as subject matter experts,
for review and verification. After these tasks were verified as being representative of
CF fire fighter duties, fire fighting equipment was catalogued, and the results are
attached as Appendix B. Physical demands and task analyses were then conducted,
and the following information was compiled for each task under consideration:
I.
ii.
. . . III.
iv.
V.
time required to complete each task associated with the job;
mass of all fire fighting equipment and the forces and torques required to
move such equipment;
height of the lifts;
frequency and distances that equipment must be carried; and,
influencing factors such as environmental conditions.
22
Figure 1: Model for the development of a bona fide physical maintenance standard
From this list of potential tasks, a circuit consisting of the most demanding and
representative tasks was developed. The circuit was refined and evolved over a period
of performance trials at CFFA. The resulting circuit was presented to a second panel of
subject matter experts consisting of members of the Canadian Forces Fire Marshall’s
office (CFFM) and representatives from both CF and DND fire stations. Both panels of
subject matter experts recommended that the circuit should be contained within a fire
station, and should require no additional equipment or modifications to the station.
Adaptations were made to the circuit in order to meet these constraints, and it was
23
subsequently approved by CFFM as the test prototype. A pilot study was undertaken
on twenty-three CF fire fighters to investigate the reliability and to determine the
physiological factors contributing to performance on the circuit. The details of this
study are provided in Chapter 4: “Pilot Study”.
The circuit consisted of ten simulated fire fighting tasks which were completed in
a continuous and consecutive manner (Figure 2) on a concrete slab floor. Rest
intervals consisting of walking a distance of either 15.24 or 30.48 metres were
incorporated between the tasks, representing the conduct of tasks at the scene of an
actual fire. The tasks comprising the circuit are detailed below:
1.
2.
3.
4.
5.
One arm hose carry (“Hose Carry”). For this task, subjects carried one section
of rolled 65 mm hose weighing 16.5 kg in one hand a distance of 15.24 m, and
returned the same distance, carrying the hose in the other hand.
3.5 m Ladder raise (“Ladder Raise”). The subject picked up a 3.5 m ladder
(mass 13.6 kg) from the floor, carried it a distance of 15.24 m and raised it
against a predetermined wall.
“Hose Drag”. The subject dragged a charged 65 mm hose a distance of
30.48 m.
First ladder climb (“Climb 1”). The subject climbed 10 rungs up and down a
7.2 m ladder 3 times.
High volume hose pull (“Hose Pull”). The subject was required to pull a 30.48 m
(100 ft) section of 100 mm hose a total distance of 30.48 m.
24
6.
7.
8.
9.
10.
“Forcible Entry”. The subject was required to move a rubber tire weighing 102.5
kg a distance of 30.5 cm across a table 76.2 cm high, by hitting it with a 4.5 kg
sledge hammer.
“Victim Drag”. For this task, subjects were required to drag a “Rescue Randy”
mannequin weighing 68.2 kg a total distance of 30.48 m. There were no
stipulations as to how the mannequin could be dragged.
Second ladder climb (“Climb 2”). Subjects were required to climb 10 rungs of
the ladder twice.
3.5 m Ladder lower (“Ladder Lower”). The subject lowered the ladder from
where it was previously erected, and carry it a distance of 15.24 m.
‘Victim Carry”. The subject was required to lift an individual weighing 61.4 kg
from a standing position and carried that individual a distance of 30.48 m,
utilizing a firemen’s carry.
Following the pilot study, the final task, ‘Victim Carry“ was replaced with the
“Spreader Tool Carry”. The replacement of the victim carry task was made in order to
standardize the testing, and in response to criticism by fire fighters who indicated that
replacement of the live victim with a 68.2 kg mannequin, to be lifted from floor height,
was an unreasonable and dangerous task. The replacement task required subjects to
lift a 36.4 kg spreader tool and carry it a distance of 30.48 m.
25
Q 3.5 m ladder carry for 15.24 m and raise - 15.24 m walk
Q
3.5 m ladder lowr * and carry for 15.24 m
- 15.24 m walk
2 x 15.24 m charged hose drag - 15.24 m walk
up/down 10 rungs x 3 - 2 x 15.24 m walk
@ ’
7.2 m ladder climb Uprdown 10 rungs x 2 - 2 x 15.24 m walk
2 x 15.24 m hose pull
2xl5.24m one arm carry with rolled 38 mm hose (change hands after 15, - 15.24 in walk
CD forcible entry . - 15.24 m walk
.24 m
FILE: FFCIRCUKMA
Figure 2: Schematic of the Circwrit
Chapter 4:
PILOT STUDY
4.1 Purpose:
The pilot study was developed to investigate the physiological demands of the
circuit and to determine its reliability prior to final approval and subsequent field testing.
Specific objectives included:
1. Quantification of the relationships between the prediction of maximum
oxygen uptake (V02 max) from field tests currently used by the CF and
VO, max as determined in the laboratory.
2. Investigation of the relationship between VO, max as measured in the
laboratory and performance on the circuit.
3. Examination of the anaerobic contribution to circuit performance.
4. Determination of the test/retest reliability of time to complete the circuit.
5. Identification of any test components which compromise the safety and/or
integrity of the circuit.
4.2 Methods:
471 sum
Subjects were 23 male CF fire fighters from 7 Wing Ottawa who volunteered to
participate. The subjects ranged in age from 21 to 42 years, with a mean age of 30.7
years (sd = 5.2).
27
All subjects were screened for medical contraindications prior to participating in
this project. The screening process included an adapted EXPRES Health Appraisal
Questionnaire (EXPRES Operations Manual, 1981). Measurements of resting heart
rate and blood pressure were conducted as described in the Canadian Standardized
Test of Fitness (CSTF) Operations Manual (Fitness and Amateur Sport, 1986).
Exclusion criteria included a resting heart rate of 2100 beats/min, resting systolic blood
pressure of 2140 mm Hg, and resting diastolic blood pressure of 2 90 mm Hg (Fitness
and Amateur Sport, 1986). In accordance with the American College of Sports
Medicine Guidelines for Exercise Testing and Prescription (ACSM, 1991) subjects 40
years of age or older were required to have clearance from a qualified physician prior
to participation in this study.
. . 3 Prelrmrnarv lnst ructions to Subiects
Preliminary instructions were forwarded to all subjects at least 72 hours prior to
their participation. Subjects were requested to forego exercise the same day as
testing, refrain from consuming alcoholic beverages for at least six hours prior to
testing, and not to eat, smoke, or drink beverages containing caffeine for at least two
hours prior to testing (Fitness and Amateur Sport, 1986). Subjects were also provided
with preliminary instructions pertaining to the recommended dress for participation
(Appendix C).
28
47 4 Infamed Consent
All subjects provided written informed consent prior to participation. Separate
informed consent forms were used for the field tests, laboratory tests, and circuit
performance (Appendix D). Subjects were aware that they were at liberty to withdraw
from the study at any time without any recourse of action.
. . 5 Testrna Sessrons
Each subject completed a field test battery at 7 Wing Ottawa, and a laboratory
test battery at Queen’s University, School of Physical and Health Education. The
testing sessions occurred between 18 October and 26 November, 1993.
All subjects familiarized themselves with the test equipment and protocols prior
to testing. In addition, each subject was provided with instructions prior to testing to
ensure their understanding of test procedures. Testing sessions were scheduled to
permit adequate recovery between testing sessions. Specifically, field test battery items
were administered on separate days, and 18-24 hours of recovery time was provided
between circuit trials. All testers were qualified to the Basic Rescuer level of
Cardiopulmonary Resuscitation. The 7 Wing and Queen’s University emergency plans
were readily available and discussed prior to the commencement of testing. All testing
sessions were completed without incident.
6 I aboratorv Tests
Resting heart rate and blood pressure, body height, body mass, girths (chest,
waist, hip and right thigh), skin folds, sit-ups in one minute, push-ups, trunk flexion, and
hand grip were collected as described in the Canadian Standardized Test of Fitness
29
(Fitness and Amateur Sport Canada, 1986). Chin-ups and the ‘l.5 mile run were
performed as described in the CFA050-23. The step test was completed as outlined in
the CF EXPRES Operations Manual (1981).
Measurement of Maximum Oxvaen Uptak
v/O* max was determined directly using a motorized Quinton treadmill and a
Sensor-Medics MCC Horizon metabolic cart. For the maximal tests, a modified Astrand
protocol which utilized a constant treadmill speed of 5.0 miles per hour (mph) was used
(McArdle et al., 1991). For the initial three minutes of the test, a 0% grade was used.
Every minute thereafter, the grade was increased 1% until volitional fatigue was
reached. A Polar Electra Vantage XL heart rate monitor was used to monitor and
record heart rate at 5 second intervals. Subjects 40 years of age and older were
required to wear a three lead EKG during the maximal test, and the tests were
monitored by an ACSM Certified Preventive/Rehabilitative Exercise Program Director.
The ACSM Guidelines for Exercise Testing Prescription (ACSM, 1991) were followed
for each test.
Twnt was identified by reviewing the plots of &No, and VENCO,. The primary
criterion to identify T,,,,t was a systematic increase in VENO, without an increase in
VENCO~. A secondary criterion was a systematic increase in the RER (Caiozzo, Davis,
Ellis, Azus, Vandagriff, Prietto & McMaster, 1982).
30 Second Arm and Lea Winaat~ Tests
Both Wingate tests were completed on calibrated Monark leg and arm cycle
ergometers. The modified ergometers were interfaced with a computer that calculated
30
mean power output (MPO) and peak power output (PPO) based on the subjects’ body
weight and pre-determined resistance loads. A warmup and familiarization period on
each ergometer was provided for subjects. The procedure consisted of 5 minutes of
cranking with a load equivalent to 40% of the calculated resistance load. The subject
determined the rate of cranking for the warmup period, which was followed by a 3
minute rest period. The resistance used for the tests was 50 g/kg and 75 g/kg of the
subject’s body mass for the arm and leg tests, respectively. Each subject pedalled as
quickly as possible, and the resistance was applied within the initial 3 to 4 seconds of
cranking. The test began when the predetermined resistance was reached. Upon
completion of the test, the resistance was quickly reduced to a minimum, and the
subject was instructed to continue cranking for at least 2 - 3 minutes. The computer
provided a printout of MP0 and PPO. Power decline (PD) was calculated by
determining the difference between PPO and lowest 5 second power output and .
dividing the obtained value by the PPO value (Maud & Shultz, 1989).
. reld Tests
t Performan=
Prior to the actual test, subjects were provided with a familiarization trial, where
they completed the circuit wearing PT clothing. For the actual test, subjects wore full
turnout gear, and performed the circuit twice, on separate days. During both trials,
subjects were required to wear a portable oxygen consumption device (Oxylog)
attached to an SCBA harness. The regular SCBA mask was replaced with the Oxylog
mask. Additional weight was added to the harness to account for the difference in
31
weight between the SCBA air tank and the Oxylog. Subjects were instructed to
complete the circuit as quickly as possible, without running.
Ratings of perceived exertion (RPE) were recorded after every task on the circuit
using a 15 point (6 to 20) Borg scale and heart rates were monitored and recorded
every 5 seconds. Absolute VOZ recordings were attempted every minute by manually
reading the Oxylog. Due to the limited capacity of the Oxylog, its capacity was
exceeded by all subjects, and these data were not used in subsequent analyses. Total
time taken to complete each task and the circuit were recorded.
Blood lactate assay
Five minute post-circuit performance venipuncture blood samples were drawn by
a registered nurse after both performance trials. All samples were drawn from the
antecubital vein, centrifuged, treated with an anticoagulant and antiglycolytic agent,
and frozen. Plasma samples were analyzed using a Yellow Springs Instruments (YSI)
Model 23L Lactate Analyzer. The YSI 23L Lactate Analyzer is linear within the range of
0 - 15.0 mMIL, and was calibrated after each subject’s sample was assayed. Any
concentrations above 15.0 mM/L were diluted for assay. A minimum of 3 analyses per
plasma sample were conducted, and this mean value was recorded. The mean values
obtained for post performance Day 1 and Day 2 were averaged, and the resulting mean
value was used for the purposes of statistical analyses. The reliability of these
methods have been documented by Wolfe, Walker, Bonen, & McGrath, (1994).
32
4.3 Results and Discussion:
. . . . 4.3.1 PhyvCharacterlstlcs of the Sub!ec&
The physical characteristics of the subjects who completed all phases of the pilot
project are summarized in Table 5. Subjects averaged 30.7 years of age, and were
both taller and heavier than average Canadian men of similar age (Fitness and
Amateur Sport, 1986). Similar findings have been reported for Canadian fire fighters by
Horowitz and Montgomery (1993) who found that Montreal fire fighters between the
ages of 30 - 39 years were taller and heavier than average Canadian men (50th
percentile of CSTF) in the same age cohort.
33
Table 5: Physical characteristics of the subjects (pilot study)
Variable
Waist-to-hip Ratio
SOS: Sum of Skinfolds (mm)
SOTS: Sum of Trunk Skinfolds (mm)
Hand Grip(left+right) Jkg)
Push-ups (number)
Sit-ups (number)
Chin-ups (number)
Trunk Flexion (cm)
57 17 33 90 40
33 11 15 52 40
114 12 90.5 146.5 60
37 13 19 56 85
41 7 29 56 80
7 5 1 25 -
28 9 12 45 45 (
The mean of the predicted VOz max from the progressive step test was 44.0 f
4.0 ml/kg/min, while the mean of the predicted VOz max from the 1.5 mile run was 43.0
f 4.0 ml/kg/min. The mean of the measured V02 max was 48.9 f 5.9 ml/kg/min or 4.19
34
f 0.51 Vmin. Significant positive correlations were found between the VOz max
predicted by the progressive step test and the VOz max measured directly (r=O.54, p <
0.01) and between the VOz max predicted from the I.5 mile run and VO, max
determined directly (r=O.81, p < 0.001). Within this specific cohort of subjects, VOz max
was under predicted by both the step test and the 1.5 mile run. These findings are
consistent with the literature on the predictive validity of the step test, (Fitness and
Amateur Sport, 1986) and the 1.5 mile run (Myles et al., 1980).
The subjects in this study were rated as being in above average aerobic
condition, and ranked at the 70th percentile of the CSTF (Fitness and Amateur Sport,
1986). In contrast, Horowitz and Montgomery (1993) reported that Montreal fire
fighters between the ages of 30 - 39 had significantly lower VO, max values than the
average Canadian (50th percentile of CSTF). These differences may be attributed to
the fact that CF fire fighters are required to meet established physical fitness standards
on a semi-annual basis.
. 4.3.3 MaxImum Anae robic Power
Performance on the Wingate leg ergometer test resulted in a PPO of 1154 watts
(13.6 w/kg) and an MP0 of 894 watts (10.5 w/kg). For the arm ergometer test the PPO
was 489 watts (5.76 w/kg), with an MP0 of 409 watts (4.81 w/kg). These values are
consistent with values reported on other segments of the CF. Specifically, Bell and
Jacobs (1986) reported a leg PPO of 10.4 w/kg and an MP0 of 7.7 w/kg for jet flight
instructors and flight control personnel. Similarly, Lee (1991) reported on a PPO of 5.9
35
w/kg and a MP0 of 3.8 w/kg on the Wingate arm tests conducted on 116 CF male
infantry personnel.
In healthy untrained subjects, TVent normally occurs between 55 and 65% of VOz
max, but often exceeds 80% in highly trained elite athletes (McArdle et al., 1991). In
this study, T,,values ranged from 67 to 85% of directly measured VOz max,
suggesting that the subjects were highly trained.
4.3.4 Field Tests;
4.3.4.1 Heart Rate
Circuit performance induced heart rates (HR) similar to those experienced
during actual fire fighting. Subjects in the present study averaged 87% of maximum HR
over the entire circuit, with a range of 65% to 93%. During actual fire fighting, high HRs
have been observed for prolonged periods of time. Reported values range from 88%
(Sothmann et al., 1992) to 95% (Gilman & Davis, 1993) of age predicted maximal HR
for approximately 7 to 18 minutes. Figure 3 illustrates the average HR across circuit
tasks for each of the two trials.
36
- DAYI UEAN -DAnwaN
Figure 3: Average heart rate for tasks on the circuit; Day 1 vs. Day 2 (pilot study)
The constant rise in HR suggests that fire fighting, although intermittent by
definition, is in fact a continuous activity because the intensity and duration of the rest
interval does not permit adequate recovery. The 15 m walks last between 7 and 9
seconds whereas the work intervals range from 13 to 45 seconds. The overall
work:rest ratio for the circuit is approximately 2.5: 1.
37
. . . 4.3.4.2 Ratios of Percerved Exertion (RPQ
The peak RPE reported during the circuit was 15, and corresponded to an
average HR of 150 beats per minute (bpm). The actual average peak HR was 165 bpm
and generally occurred during the victim drag and second ladder climb. The fire
fighters rated this part of the circuit the most difficult with average RPE ratings of 15
and 14, respectively. The fire fighters’ RPE scores and HRs indicated that the circuit
required a near maximal aerobic effort.
4.3.4.3 Post-Circuit Performance Lactates
The high mean lactates following performance on the circuit indicated a
substantial involvement of the anaerobic system. The mean post-circuit performance
lactate values were 16.0 mM/L for Day 1 and 16.7 mM/L for Day 2. On average, lactate
for trained men between the ages bf 20 - 40 years is within the range of 11 to 14 mM/L,
but may exceed 20 mM/L (Astrand & Rodahl, 1986) following very strenuous exercise.
The values reported in the present study were greater than the values reported by
Gledhill and Jamnik (1992a). This may be attributed to the different testing protocols.
The values obtained in the present study were post performance on a 10 item circuit
completed in a sequential manner with short periods of walking between tasks,
whereas Gledhill and Jamnik (1992a) reported peak lactates following the completion
of single fire fighting tasks.
4.3.4.4Circuif ComWion Times
The mean circuit performance times on Day 1 and Day 2 were 6:06 f 0:41 and
5:51 f 0:43 respectively and are presented in Table 6. These completion times cannot
38
be readily compared to those described in other studies, as the tasks within each circuit
are different, and testing protocols vary. Tasks are generally representative of the
specific duties performed by a particular group of fire fighters, and there are unique
situations which apply to CF fire fighters and their civilian counterparts. Specifically,
CF fire fighters may be required to conduct victim rescue operations in scenarios of
fighter jet or passenger aircraft crashes or deal with fires on board ships, whereas their
civilian counterparts may not have such responsibilities. Similarly, civilian fire fighters
may be required to conduct victim rescues in buildings containing numerous flights of
stairs, whereas the majority of military buildings do not contain more than three flights
of stairs.
Table 6: Circuit performance times (min:sec) (pilot study)
Day Mean
1 6:06
2 551
5 Correlation of Test Variables
Std Dev
0:41
0:43
Minimum
4:46
4:42
Maximum
7133
7:09
The Pearson product moment correlation coefficients between all test variables
are summarized in Table 7. Significant negative correlations were found between
measured VOZ max (Urnin) and performance time on the circuit (I=-0.83, p < O.Ol), and
between predicted VO, max derived from the 1.5 mile run and performance time on the
circuit (r=-0.76, p < 0.01). Thus, the time required to complete the circuit decreased as
39
aerobic capacity increased. This finding is supported by previous studies which have
demonstrated that the performance of fire suppression tasks is enhanced in those fire
fighters with high VOz max values (Adams et al., 1986; Davis, et al., 1982; Sothmann et
al., 1990).
Table 7: Pearson product moment correlation coefficients (pilot study)
Vatlable Arm AnIl MP0 PPO
Leg PPO
Age V02 max
vo, at TtU
%VO, Circuit atT, time
Blood Body lactate Masa Conc’n
&ml 1.00 MP0 (w)
Z(w) 0.90” 1.00
LegMPO 0.17 0.09 1.00 PJ@
Leg PPO 0.11 0.12 0.93”’ 1 .W PJ4
rw -.031 -0.31 0.22 0.39 1.00
vo, max 0.41 0.32 0.40 0.29 -0.17 1.00 VW
voa at 0.27 0.24 0.43” 0.38 0.08 0.79”’ 1.00
F&
%VO2 -0.35 -0.25 -0.01 0.02 0.45 -0.42 0.14 1.00 maxat Tim
circutt -0.38 -0.33 -0.21 -0.14 0.20 -0.83’ -0.63’ 0.34 1.00
z
BbOd 0.20 -0.27 -0.28 -0.32 -0.15 0.29 0.34 0.17 4.23 1.00 Lactate
gg
El2 0.W 0.41’ 0.33 0.293 0.20 0.53” 0.45’ -0.31 4.22 -0.00 1.00
NJ)
l Signitkant at p * 0.05 “Significant at p s 0.01 -Significant at p < 0.001
40
VOz (ml/kg/min) at Tvbnt was significantly correlated (r=O.37, p ~0.05) with post
circuit performance blood lactate results. VOz (Ilmin) at Twnt was also significantly
correlated with performance time on the circuit (r=-0.63, p < 0.005) indicating that as
VO1 at T- increased, the time taken to complete the circuit decreased. A significant
correlation was found between VOz max (Vmin) and VO; (Vmin) at Tmt (r=0.79, p <
0.001). This significant correlation may be best explained by the fact that these
variables are closely related since ventilatory threshold increases with improvements in
aerobic capacity.
No significant correlations between post-circuit performance blood lactates, arm
and leg Wingate measures, and circuit performance were found. Negative correlations
between circuit performance time and Wingate leg and arm MP0 and PPO scores
indicate that a high anaerobic capacity should result in lower circuit completion times.
4.3.6 Circuit Test-Retest Reliabilitv
The mean (& standard deviation) circuit performance times on Day 1 and Day 2
were 6:06 f 0:41 and 551 f 0:43 minutes, respectively. The test-retest reliability
coefficient for circuit performance time was r=0.93 (p < 0.001). Correlations for
individual tasks within the circuit for Day 1 and Day 2 ranged from 0.52 to 0.95. Table
8 provides the correlation coefficients (and their corresponding significance
probabilities) for each task comprising the circuit for time, maximum heart rate
(HRmax), average heart rate (HRavg), and RPE.
41
Table 8: Correlations measuring the reliability of four performance measures for individual tasks comprising the circuit (pilot study)
Task II Time HRmax HRavg RPE
I! r I r I r r
Hose Carry 0.759 0.603 0.605 0.599
Ladder Raise 0.563 0.683 0.756 0.426*
Hose Drag 0.954 0.564 0.560 0.669
Ladder Climb 1 0.879 0.526* 0.565 0.592
Hose Pull 0.529 0.796 0.623 0.687
Forcible Entry 0.539 0.782 0.710 0.716
1 0.522’ 0.820 0.682 0.806 Victim Drag
Ladder Climb 2
Ladder Lower
Victim Carry All correlations, except where indicated, are significant at pcO.01.
l Significant at pcO.05 W Significant at pcO.055
42
4.4 Conclusion:
The information derived from completion of this pilot study represents the first
steps necessary in the creation of a bona fide occupational requirement. The ERG has
taken a research approach that has considered expert opinion, the nature of duties to
be performed, conditions in the workplace, and existing scientific and empirical data.
This was accomplished through an extensive literature review and the establishment of
two subject matter expert panels. Development of the test circuit was based on the
concept of providing an instrument that was comprised of simulations of essential fire
fighting tasks.
Information provided by the expert panels, and comments from the subjects
within this phase of the study confirmed that the circuit is a valid test of fire fighting
proficiency. Performance data has confirmed that the circuit is reliable in terms of time
to complete (r = 0.928) as well as in its ability to evoke physiological responses which
are similar to those reported under actual fire fighting conditions.
Following consideration by CFFM and in the interest of safety and
standardization of the circuit, a change was made to the victim carry task. This task
originally required the hoisting of a 150 lb mannequin from the floor to an over-the-
shoulder position (“fireman’s carry”), and was subsequently modified to picking up and
carrying a person from a standing position. This was replaced by the carrying of the
spreader tool from the jaws of life. At 36.4 kg, it represents a frequently occurring task
that is performed by a single fire fighter.
43
Chapter 5:
MAIN DATA COLLECTION PHASE
Development of a Physical Maintenance Standard for CF and DND Fire Fighters
5.1 Purpose:
The main data collection phase of this research project assessed circuit
performance across all segments of the CF and DND fire fighter population. Data were
collected on both genders, as well as across the age and fitness range represented by
the incumbent force. The ERG research team travelled to Canadian Forces Bases:
Borden, Chilliwack, Comox, Esquimault, Halifax, North Bay and Petawawa for data
acquisition during April to June, 1994. Fire fighters from these bases as well as CF fire
fighters from CFB Greenwood and Shear-water participated in the study. During that
period data were collected on 202 male and 7 female fire fighters. To increase the
number of women within the sample, additional testing of 17 professional fire fighters
was undertaken in Toronto (October, 1994) and in Winnipeg (December, 1995).
The development of a single performance standard was based on the
performance of incumbent fire fighters on the circuit, which contained actual fire fighting
tasks. This standard applies to all segments of the CF and DND fire fighting force.
44
5.2 Methods:
52.1 Sub_iecQ
A total of 226 subjects completed the protocols associated with the project. The
sample consisted of 202 male and 24 female fire fighters. Of the 202 male subjects,
102 were CF and 100 were DND fire fighters. For the females, 2 were CF, 5 were DND
and 17 were professional fire fighters within various civic forces. Therefore, women
accounted for ‘IO.6 % of the total sample.
52.3 Pre-Screening
All subjects were screened for medical contraindications prior to inclusion in the
study. The screening process included an adapted EXPRES Health Appraisal
Questionnaire (EXPRES Operations Manual, 1981; Appendix E). Measurements of
resting heart rate and blood pressure were conducted as described in the Canadian
Standardized Test of Fitness (CSTF) Operations Manual (Fitness and Amateur Sport,
1986). Exclusion criteria included a resting heart rate of 2100 beats/min, resting
systolic blood pressure of 2140 mm Hg, or resting diastolic blood pressure of L 90 mm
Hg (Fitness and Amateur Sport, 1986). In accordance with the American College of
Sports Medicine Guidelines for Exercise Testing and Prescription (ACSM, 1991)
subjects 40 years of age or older were required to have clearance from a qualified
physician prior to participation in this study.
52.3 Instruct . ions to Suw
Subjects were requested to forego exercise the same day as testing, refrain
from consuming alcoholic beverages for at least six hours prior to testing, and not to
45
eat, smoke, or drink beverages containing caffeine for at least two hours prior to testing
(Fitness and Amateur Sport, 1986). Subjects were also provided with preliminary
instructions pertaining to the recommended dress for participation (Appendix C).
52.4 Informed Consent
All subjects provided written informed consent prior to participation (Appendix
D). Subjects were aware that they were at liberty to withdraw from the study at any time
without penalty.
52.5 Testing Sessions
Following the screening process, each subject’s body mass was recorded, and
all subjects completed a submaximal step test (Fitness and Amateur Sport, 1986) with a
starting cadence determined by their age and gender. Subjects performed a circuit
walk-through, without fire fighting gear and with instruction, to familiarize themselves
with the test equipment and protocols prior to testing. Subjects understood that the
goal of the test was to complete the entire circuit as quickly as possible, without
running. During the same testing session subjects also performed a practice run of the
circuit in full turnout gear with SCBA. Approximately 24 hours later, subjects returned
to complete the actual test run of the circuit.
. . 52.6 Clrcult Pe r-forma-
For performance on the circuit, subjects were required to wear full turnout gear
(boots, gloves, flash-hood, and Goretex bunker pants and jacket). Subjects were also
required to wear an SCBA harness with a full oxygen tank. The total time taken to
complete the circuit and the time to complete each task were recorded. Heart rate was
46
monitored by a Polar Electra Vantage XL monitor and recorded at 5 second intervals
throughout circuit performance. After the completion of each task within the circuit,
subjects indicated their perceived exertion (RPE) on a Borg scale.
Following revisions to the circuit format resulting from the pilot study, the circuit
consisted of 10 simulated fire fighting tasks, to be completed in a continuous manner.
Rest intervals consisting of walking either a distance of 15.24 (between all tasks with
the exception of the ladder climbs) or 30.48 metres (following the ladder climb tasks)
were incorporated between tasks, representing the conduct of tasks at an actual fire
scene.
The first task in the circuit was a one arm hose carry. The subject carried one
section of 65 mm hose weighing 15.9 kg in one hand a distance of 15 m, then returned
the same distance with the hose in the opposite hand. The subject then picked up and
carried a 3.6 m ladder (13.6 kg) 15.24 m and raised it at a specified location. The next
task involved dragging a 30 m length of 65 mm charged hose a distance of 30.48 m.
The subject then returned 15 m and ascended a 7.2 m ladder, consisting of 3
repetitions of 10 rungs up and down. The high volume hose pull, which consisted of
performing a hand over hand pull of 2 x 15 m sections of 100 mm hose for a total
distance of 30.48 m, was followed by the forcible entry simulation. Here, the subject
was required to move a rubber tire (102.5 kg) a distance of 30.5 cm on a 76.2 cm high
table by hitting it with a 4.5 kg sledge hammer. The forcible entry task was followed by
a victim rescue, where the subject was required to drag a Rescue Randy mannequin
(68.2 kg) 30.48 m. The mannequin could either be lifted or dragged, but an under the
47
arm hold was required. For the second 7.2 m ladder climb, the subject completed 2
repetitions of 10 rungs up and down. The ninth task involved lowering the 3.6 m ladder
and returning it 15.24 m to its original location. The final task in the circuit was the
spreader tool carry (36.4 kg), where the subject picked up and carried the tool a total
distance of 30.48 m. All data gathered from completed trials were processed and
analyzed using the STATISTICA Analysis package (Statsoft Inc., 1994) and the SAS
programme (SAS Institute Inc., 1985).
5.3 Results:
. . . . 5.3.1 Desc~~~tlve~t~cs
A total of 226 fire fighters (consisting of 202 men and 24 women) completed all
stages of the testing. The age distribution by gender and service are provided in Table
9.
Table 9: Age distribution of subjects by gender and service
II Male II Female Aged * CF DND CF I DND Professional
36 15.9
+ 5 2.2
48
5.3.2 Indirect Measures of Maximum Oxvoen Uptake
The mean (& standard deviation) of the predicted VOZ max from the progressive
step test was 42.39 f 6.3 ml/kg/min. The mean by gender was 35.6 f 3.4 and 43.1 f
6.1 mVkg/min for women and men, respectively. A breakdown of the mean predicted
VOz max by gender, service and age category is provided in Table 10.
Table IO: Mean predicted V02 max (mllkglmin) f standard deviation by gender, service and age category
Age (years) Male Female
CF DND CF I DND Professional
s 1 37.42il.85 1 37.60 k2.77
31.03 f 3.49 1 36.23 i2.35 1 34.79i3.19
w I w I 30.33'
~ 50-59 II 38.18' 32.94 f 1.92 - - I / l : Standard deviation not provided. (N=l)
Categorization of the current sample into fitness ratings as defined by the CSTF
normative data for predicted VO, max (Fitness and Amateur Sport, 1966) resulted in
the distribution presented in Table 11. Completion times for the circuit are presented in
conjunction with the fitness rating data.
49
Table 11: Mean circuit performance times (min:sec) by fitness rating
Rating
Excellent
Above Average 1 55 1
Number Minimum Maximum Mean Std Dev
28 5:02 1059 658 1:26
5:05 1 13:42 1 7:30 I 1:58ll
Average 97 5:22 12:42 7:50 1:30
Below Average 44 5:45 18i5 8:26 2:16
Poor 2 7137 9127 8:32 1:18
5.3.3 Circuit Comoletion Times
The mean circuit performance time was 7:46 with a range of 5:02 to 18:05. The
average time to completion for men was 7:30 (5:02 - 12:42) and 9:57 (6:30 - 18:05) for
women. The breakdown by gender, service and age category is provided in Table 12.
50
Table 12: Circuit performance times (min:sec) by gender, age and service
Gender 1 Service
T
DND
--l-Gsz Grand
Age N Mean Std Dev Minimum Maximum
20-29 29 6:31 0:47 505 9:oo
30-39 61 7:lO 1:22 5:02 12:25
40-49 11 7:58 1:17 5:43 10:25
so-59 1 12:lO - 12:lO 12:lO
20-29 6 7:04 1:02 6:05 8:48
30-39 53 7:34 I:19 5:26 lo:56
40-49 I 36 I 8:13 1 1:35 I 5:46 12:17
50-59 5 10:13 I:47 8:52 12:42
30-39 2 13:42 6:12 9:19 18:05
20-29 2 12:06 0:28 11:46 12:26
30-39 3 11:32 2:08 9:26 13:42
20-29 8 8:59 I:42 7:35 12:15
30-39 8 9:05 157 6:32 11:30
40-49 1 8:08 8:08 8:08
226 7:46 1:48 5:02 18:05
There were no statistical differences between the circuit completion times for the
two services. The average time (k standard deviation) to complete the circuit for CF
fire fighters was 7: 14 f 1:44; and for DND fire fighters was 8:05 f I:45 The Pearson
correlation coefficient for the total time and step test scores was -0.529 (pcO.0001).
5.3.4 Impact Analvses
A series of analyses were performed on the current data set to determine the
proportion of the sample that would be cut by the imposition of three different
performance objectives. The initial choice of a cutting score was determined by
51
choosing the circuit completion time corresponding to VO, max values cited in the
literature as being adequate for performing fire fighting duties. The range of minimum
values reported was from 35 ml/kg/min to 45 ml/kg/min. The average circuit completion
time associated with a VO, max of 44 ml/kg/min was 8 minutes. The average V02 max
for the subjects not passing an 8 minute performance objective was 38 ml/kg/min. The
second cutting score was selected using the empirical approach first adapted by the
ERG for MPFS (Stevenson et al., 1988). Specifically, a circuit completion time
corresponding to a successful completion rate by approximately 75% of the sample was
determined. The resulting performance objective for a cut off representing a 73.5%
passing rate was 8 minutes and 30 seconds. For this performance objective, the
average predicted VO, max for the passing group was 43.81 ml/kg/min, while the failing
group averaged a predicted V02 max of 37.9 ml/kg/min. The selection of a third
performance objective of 8 minutes and 15 seconds corresponded to the midpoint of
the range in time. The corresponding predicted V02 max for the passing group was
44.1 ml/kg/min and 38.1 ml/kg/min for the failing group.
The impact of the three performance objectives on the overall sample is
displayed in the Kaplin-Meier curve in Figure 4. The 95% confidence bands are
provided to illustrate the minimum and maximum impact on the current sample of each
of the choices under consideration. For example, although the average percentage of
the sample that would be cut using the 8 minute performance objective is 35% the
range would be from 30% to 42%.
52
. 8.00 min cut-off = 34.96% cut (29.26-41.76) 8.25 min cut-of! = 29.65% cui (24.25-46.24) a” ““^, . ,“” “” “” ” *. 8.50 min CUi-OlT = ZS.bb% GUI (ZUAb-YZ.LS)
,...._ +. &..“I ) ; ; ; ; i ; ; ; 1.
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‘j lilL,i 1 1 ; / ; j i ; . _. --f%; -1 . ‘!i * . . . . . . . . . . .
; .,.-..” . . . . . . f”..“““.“! . . . . i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i . . . . . . . . . ...“. i . . . . . . . . . . . . . . . i . . . . . . . . . . . . . . . i . . . . . . . . . . . . . . . . i . . . . . . . !\ f ; k, . . . \ . . . . . . . . . i . . . . . . . . . . . . . . . i- ..--. -.... -...i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..~ . . . . . . . . . . . . . . . i . . . . . . . . . . . . . . . i. . . . . . . ..__..... _._......._...._’ . . . . . . .
‘i<! --L”.\*
:_.‘<,.; i i ! ! ! j
; i ; i i f , :’ : ..% :~.“.““..“....“.....~ . . . . . . . . . . . . . . . f . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . f. ,............. j . . . . . . . . . ..“..~“...” 1. L-L., L.... )-%.. ii.. i L..- -...A. %.A ..“..” : . . . . . . . . . . ..i . .._..._.__..._ i.2.:,:,: .*--...... -- . . . j . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .._ .:..* ._..,_......: . . . . .
6 8 10 12 14 16 lE
Cut-off Time (min)
Figure 4: Kaplin-Meier Curve with 95% confidence bands (circuit completion times)
The impact of the three performance objectives on gender is illustrated in Figure
5. It is important to note that the sample sizes differ dramatically: 202 men and 24
women. Within the sample tested, it is evident that the impact of moving from a cut off
score of 8:30 to 8:00 results in an increased failure rate of 8% for men (from 22% to
30%) and of 19% for women (from 59% to 78%).
53
male female
Gender
Figure 5: Impact of performance objectives on gender
Figure 6 illustrates the impact of the performance objectives as a function of age
category. The six subjects in the 50 - 59 year age category would be excluded with the
implementation of any of the three circuit completion times. The failure rate would be
expected to move from 38% to 48% for the 48 subjects in the 40 - 49 year age
category. Similarly, for the 127 subjects in the 30 - 39 year age category, an increase
in the failure rate from 22% to 32% would be expected. Finally, the failure rate would
be expected to climb slightly from 16% to 20% for the 45 subjects in the 20 - 29 year
age category.
54
30-39 40-49
Age Category (years)
800
8:25
8:50
Figure 6: Impact of performance objectives as a function of age category
The evaluation of these performance objectives on the three services,
represented within the sample, resulted in an incremental impact on the failure rate by
decreasing the required completion time. Figure 7 illustrates the impact on each of the
services tested. It should be noted that the profile of the DND group reflects a larger
proportion of both older subjects and more women than the CF group. The
professional group was comprised solely of female subjects.
55
Figure 7: Impact of performance objectives on service
m 890
W 8:15
CF DND Pd. m 8~30
Service
A performance objective of between 8:00 and 8:30 minutes would not only fall
within one standard deviation of the grand mean of the sample (see Table 12) but it
would also fall within one standard deviation of the separate means for gender, service
or age. As Table 12 confirms, the specific groups most adversely affected by the
imposition of a performance objective within this range would be female subjects and
those subjects in the 50 - 59 year age category.
5.4 Discussion:
The descriptive statistics related to the sample under investigation confirm their
similarity to the characteristics of the population of CF and DND fire fighters.
Specifically, the majority of subjects were male (approximately 90%) and between the
56
ages of 20 and 39. As expected, there was a higher proportion of DND fire fighters in
the 40-59 age category, which can be accounted for by the differing career paths of the
two groups.
In terms of the VOZ max scores predicted from the step test, the mean scores for
both genders fall within the range of necessary aerobic fitness levels cited in the
literature. It should be noted that one of the weaknesses of the step test is that it tends
to underestimate the fitness levels of women and highly trained individuals, while
overestimating the fitness levels of less fit individuals. This fact notwithstanding, 37%
of the current sample were categorized as having “above average” or “excellent” fitness
ratings when compared to the CSTF normative database (Fitness and Amateur Sport,
1986). An additional 43% of subjects were categorized into the fitness rating of
‘average”, while the remaining 20% of subjects were categorized as “below average” or
‘poor”. Given the inherent bias of the step test, higher proportions of the sample may
be expected to fall in both the upper and lower ends of the distribution.
Characterization of the current sample suggests that this group of fire fighters conforms
to many of the attributes of the larger fire fighting population, as reported in the
literature.
The comparison of circuit completion times with the fitness ratings revealed that,
for subjects in the “average” to “excellent” fitness ratings, the mean time to completion
ranged between 658 and 750. The relatively large standard deviations associated
with this comparison represents the variation within the categories that can in part be
attributed to averaging over age and gender. A more systematic evaluation of the time
57
to complete the circuit as a function of gender, age, and service has been summarized
in Table 12. It reflects a very wide range in performance that is evident throughout the
various impact analyses which were conducted.
In light of both the relatively poor fitness levels of females within this sample,
and their concomitant slower completion times on the circuit, a substudy was designed
to evaluate the performance characteristics of physically fit females on the test circuit.
It was recognized that subjects in the women’s substudy were not bona fide fire
fighters, and therefore were not part of the overall subject pool. As such, data from
this substudy were used only to assess the probability of women with a VOz max in
excess of 35 ml/kg/min to complete the circuit within each of the three performance
objectives under consideration. The details of that study are presented in Chapter 6 of
this report. As well, the recommendations emanating from the main data collection
phase are contained in Chapter 8.
58
Chapter 6:
WOMEN’S SUBSTUDY
6.1 Purpose:
This study was conducted to evaluate the effects of practice on the circuit using
physically fit (non-fire fighter) women. The specific objectives of the study were to:
a) Characterize the performance of physically fit women (defined by an
“above average” V02 max) on the circuit,
W Examine the effects of increased practice sessions on the total time to
complete the circuit.
6.2 Methods:
52.1 Subjece
Subjects for this study were 9 healthy female volunteers, aged 28;37 years, who
had no previous fire fighting experience. Selection criteria were based on a minimum
aerobic capacity for their age groups, as per the CSTF. Specifically, women aged 20-
29 years were required to have an aerobic capacity of 37 ml/kg/min, whereas the
criterion was 34 ml/kg/min for women aged 30-39. All subjects completed an adapted
EXPRES Health Appraisal Questionnaire (CF EXPRES Operations Manual, 1981;
Appendix E), and were screened for resting heart rate and blood pressure, as outlined
in the CSTF Operations Manual (Fitness and Amateur Sport, 1986).
59
52.2 Orientation
One week prior to the commencement of the study, an orientation meeting was
held to provide detailed information to the participants. At this time, all subjects were
instructed not to exercise on the same day as the laboratory and practice sessions, to
refrain from consuming alcohol six hours prior to the testing and sessions, and to
refrain from eating, drinking caffeinated beverages, and smoking at least two hours
prior to the testing sessions (Fitness and Amateur Sport, 1986; Appendix C). Subjects
read and signed informed consent forms prior to commencing the study (Appendix D).
6 7.3 Testing Schedule
Table 13: Summary of testing sessions (women’s substudy)
Dates
October 1 and 11, 1994
Test Items
Laboratory testing: body composition, strength tests, and maximal treadmill tests
Location
Queen’s University
October 3,1994 1. Familiarization of test 7 Wing Ottawa circuit 2. Step test 1 (“pre-test”)
October 4-28, ‘I 994 Practice sessions 1 7 Wing Ottawa through 7
November 3,1994 1. Step test 2 (“post-test”) 7 Wing Ottawa 2. Practice session 8
During the familiarization session, a CF fire fighter demonstrated the tasks
comprising the circuit, and provided a breakdown of skills for each individual task.
60
Alternate techniques were also demonstrated to permit subjects to determine which
technique best suited their needs. Subjects were provided the opportunity to practice
each task.
The practice sessions were conducted twice weekly for four weeks. The
sessions were scheduled Monday and Friday or Monday and Thursday to provide
adequate recovery time between sessions. The final session (8) was conducted one
full week after session 7.
4 Laboratory tests
Prior to the commencement of the testing sessions, subjects completed the
following laboratory tests:
1. Anthropometrics; Standing height and body mass, waist and hip girths, and
skinfolds of the triceps, biceps, subscapular, iliac crest, and medial calf were measured
in accordance with the CSTF Operations Manual (Fitness and Amateur Sport, 1986).
2. Body Comoosition; Fat mass was estimated by means of hydrostatic weighing
(McArdle et al., 1991).
. 3. Aerobic C apacitv CVQ, maxi; Maximal oxygen uptake (VOz max) was determined
using a motorized treadmill and metabolic cart. The subjects’ maximum heart rates
during the warmup period were used to assign the subjects to one of two protocols;
subjects with a heart rate of ~160 beats per minute were assessed using the modified
Astrand protocol, and those whose heart rates were ~160 bpm were assessed using a
different protocol (MacDougall, Wenger & Green, 1991). This second protocol was
61
adopted for the elite athletes in the subject group so that the actual treadmill testing
time could be kept within the 12 minute period.
4. Muscular strength; All three muscular strength tests were performed before the first
session. Prior to each test, subjects warmed up with a self-selected weight for a
minimum of 10 repetitions. During each test, subjects selected a starting weight and
were permitted a maximum of three attempts at each weight, with a two minute rest
period between trials. The last successful lift was defined as the subject’s maximal
effort.
a) Bench Press: The bar height was adjusted individually for each subject. A
successful lift was defined as a smooth execution to full elbow extension without
stopping. The load was increased by a minimum of 2.2 kg (maximum 13.6 kg)
after each successful trial.
b) Pull-down: The height of the bar was adjusted for each subject. A successful
trial was defined as a pull-down from a full extension to 90” elbow flexion. The
load was increased a minimum of half a plate, to a maximum of 3 plates.
c) Leg Press: A successful press was defined as the movement from the start
position with the subject’s feet on the press platform to full leg extension. The
load was increased between 9-40 kg after each successful trial.
52.5 Field test
The CSTF Step Test (Fitness and Amateur Sport, 1986) was conducted to
estimate aerobic capacity prior to the first session and following the seventh session.
62
All practice sessions were conducted on the circuit, and subjects were required
to wear full turnout gear, including self-contained breathing apparatus (SCBA). Heart ,
rates were monitored using a Polar Electra Vantage XL monitor at 5 second intervals.
Time per task and total circuit time were recorded. The total air used from the SCBA, in
pounds per square inch (psi) during each trial was also recorded.
The circuit used in this study was identical to the circuit used throughout the
main study. Subjects were given the option to use an assist device (piece of rope; a
common tool of a CF fire fighter) to perform the Victim Drag task.
Each subject was instructed to complete the circuit in a continuous and
consecutive manner as quickly and safely as possible, without running.
6.3 Results:
The characteristics of the women who completed all aspects of this substudy are
provided in Tables 14 and 15.
63
Table 14: Subject Characteristics (women’s substudy)
Characteristic I
Mean
Age (years)
Height (cm) I 164.6
Mass (kg) 61.1
Body Mass Index (BMI) (kg/m*)
Waist to Hip Ratio (WHR)
Sum of Skinfolds (SOS) (mm)
46.3
Sum of Trunk Skinfolds (SOTS) (mm)
19.6
Body Fat (%) I 23.5 5.76 1 16.5 1 34.2
Step Test 1 (ml/kQ/min)
39.9
Step Test 2 (ml/kg/min)
41.4
V02 max (ml/kg/min)
45.2
Std Dev Minimum Maximum I
2.83
13.03
38.3 I
52.0
64
Table 15: Results of strength tests (women’s substudy)
Test I
Me’an I
Std Dev I
Minimum Maximum I
Bench Press (kg) 64.22 2264 40.86 102.15
Leg Press (kg) 217.42 149.30 98.75 442.65
Pull Down (kg) 61.41 11.41 43.13 81.72
6.3.1 Maximum Oxvaen Uptake
The mean of the predicted V02 max derived from the step tests prior to and at
the conclusion of the study were 39.9 and 41.4ml/kg/min, respectively, while the V02
max derived from the treadmill test was 45.22 ml/kg/min. Significant Pearson
correlation coefficients were observed between the treadmill assessment and the pre-
and post-test step tests (r = 0.70 and 0.90, respectively; ~~0.05). Analysis of the step
test results using a t-test for dependent samples revealed a small (1.5 ml/kg/min), but
statistically significant difference between pre- and post- test scores (t,,=-2.486;
pcO.05).
6.3.2 Total Circuit Time
Overall, the total time to complete the circuit decreased as the subjects
completed more practice sessions. The initial mean circuit time of 8:52 was reduced to
656 by the last session, representing a 1:56 improvement in mean performance. The
largest decline in mean total circuit time was observed between sessions 1 and 2 (42
set). Analysis of variance (ANOVA) with repeated measures revealed a main effect of
day on circuit time (F,,W = 14.32; p<O.OOOO), and post hoc tests revealed that there
65
was a progressive improvement in the total circuit time across sessions. Figure 8
illustrates the decrease in total circuit time over the 8 sessions.
Over the 8 practice s&sions, individual performance improvements ranged from
051 to 453.
1o:oo
9:20
c 8:40
iz . .
g 890
iii .- t-
7:20
6:40
6:00 I
1
I
2
I
3
I I I I I
4 5 6 7 8
Session Number
Figure 8: Mean total time on circuit (2 standard error) (women’s substudy)
53.3 Individual Test Items
The time required to complete each task within the circuit was quantified, and
changes in task time over the 8 sessions were analyzed. Results of repeated
measures analyses of variance on each task showed that the time required to complete
66
the forcible entry and the victim drag tasks did not change significantly with repeated
practice sessions. l
. 8.3.4 Air consumpt ion durina the circuit sessions
Air consumption was estimated by recording the difference in air pressure in the
SCBA air bottle before and after circuit completion. Mean pressure differences for
sessions 1 and 8 were 13.2 f .67 and 11.9 f 0.83 psi, respectively. Repeated
measures analysis of variance indicated that mean air consumption did not differ
significantly across all sessions.
53.5 Maximum heart rate
The peak heart rate of the subjects ranged from 157 to 200 beats per minute
during circuit performance. Repeated measures analysis of variance revealed that the
mean value of this maximum heart rate was not significantly different across practice
sessions.
6.4 Discussion:
The nine women who participated in this study had high levels of aerobic fitness.
Their VOz max results ranged from “above average” to “excellent”, according to the
CSTF. The mean V02 max as predicted by the step test placed these women in the
95th percentile of the Canadian population. The mean VO,max predicted by the initial
step test (‘pre-test”) underestimated the maximal treadmill test mean of 45.2 ml/kg/min.
This finding is consistent with the literature (Jette, 1979) which acknowledges that the
67
step test underestimates V02 max for physically fit participants (Fitness and Amateur
Sport, 1986). \
Statistically, the V02 max estimated by the pre-test step test is significantly lower
than the value predicted by the post-test step test. This difference is well within the
error of the measurement tool, as the step test uses resting heart rate in the prediction
equation (Wolfe, Cunningham, Davis, & Rechnitzer, 1978). Any increases in resting
heart rate, which may be partially attributed to the subjects’ apprehension of the study,
would negatively affect the predicted V02 max. As these women were very fit, trained
individuals, it is clear that no significant physiological changes resulted from the
repeated practice sessions. Improvements in performance may be attributed to the
subjects’ increasing familiarity with the circuit and tasks (skill development), and not
due to actual changes in their fitness level.
6.4.1 Total Circuit Time
The total time required to complete the circuit decreased consistently across
repeated practice trials. This may be attributed to the subjects’ increasing familiarity
with the individual tasks comprising the circuit, the SCBA, and the physical demands of
the circuit itself. The tasks are interspersed with brief periods of walking, which may be
used in a variety of ways. Some individuals may use the walks as a means of “active
rest’ between the tasks, while others may walk very quickly in an effort to reduce their
total circuit time. It would be expected that the subjects would experiment with these
pacing strategies, as well as with task techniques, before they arrived at a method
which provided them the fastest completion time.
68
The total circuit time for the first practice session was significantly different from
the times recorded for sessions 3 to 8, although the largest inter-session decrease in
total circuit time (42 seconds) occurred between sessions 1 and 2.
Sessions 7 and 8 were not significantly different from each other. This plateau
may suggest a “levelling off of learning, and that the subjects have either reached or
are approaching their fastest circuit time, where they are limited by their physiology,
rather than by their lack of familiarity with the tasks comprising the circuit. Thus, by
their seventh exposure to the circuit these subjects had developed optimal strategies
for completing the circuit.
The mean time to complete the victim drag and forcible entry tasks did not
decrease significantly over the practice sessions. These tasks require substantial
upper body and lower back strength, and the fact that the time required to complete
these tasks did not change suggests that technique does not play a major role in the
successful completion of these tasks. An individual’s strength thus appears to dictate
the time required to complete these tasks.
The results of this substudy indicate that practice sessions may significantly
reduce the total time required to complete the circuit. For very fit females with no fire
fighting experience, this reduction in total circuit time represented an average decrease
of 152, which is a statistically significant improvement in performance. There were no
physiologically significant improvements in the subjects’ aerobic capacity as a result of
repeated exposure to the circuit, although some changes may be possible for those
individuals who are not in “above average” or “excellent” condition. The performance
69
improvements experienced by these subjects were attributed to an increased familiarity
with the tasks and the physical demands of the circuit, as well as the adoption of pacing
strategies. As the circuit is comprised of common fire fighting tasks, experienced fire
fighters would likely not reduce their circuit time as much as these subjects, as they are
already familiar with the tasks. It is expected, however, that practice sessions would
provide experienced fire fighters with the opportunity to develop pacing strategies to
complete the entire circuit, and thus reduce their total circuit time.
70
Chapter 7:
FORCIBLE ENTRY SUBSTUDY
7.1 Introduction:
Forcible entry was identified as one of the most physically demanding tasks in
fire fighting by the expert panel. Forcible entry itself is not amenable to duplication in a
circuit test because the physical effort can be highly variable and the destruction of
structural material is not practical.
Simulated forcible entry is used primarily to test upper body strength and
effectiveness with a fire fighting tool (Pelot, Klatt, & Lachance, 1994). Previous
simulated forcible entry tests have varied dramatically in the objects struck and the test
protocol. For example, simulated forcible entry tests have included striking a railroad
tie (Davis et al., 1982) hitting a tire mounted on a railroad tie (Davis, Dotson, & Santa
Maria, 1978) a car tire (Bruno, 1988; Misner, Plowman, & Boileau, 1987) a log
(Brooks, 1991) a truck tire (Louhevaara, Soukainen, Lusa, Tulppo, Tuomi, & Kajaste,
1994), and a 75 kg beam (Davis, 1995). One test required the subjects to swing a
hammer handle tied to a weighted stack in a dual pulley system (Schonfeld et al.,1990).
When designing the simulated forcible entry test, over a dozen designs were
considered with developments proceeding on one design which was the most
promising to meet the inclusion criteria previously stated. The forcible entry test
developed for the circuit consists of striking a weighted truck tire with seven sand bags
(each weighing 4 kg) for a total of 105 kg. The tire was positioned on a table top
covered with a plywood surface. The fire fighter must hit the tire with a 4.54 kg sledge
71
hammer until it moves a distance of 30 cm. The sandbags were used to add weight to
the tire because they helped to stabilize the tire, and they could be adjusted to increase
or decrease the difficulty of the test. Some of the advantages of this simulation include
the low cost, easy set-up and durable nature of the equipment. During the months prior
to completing this current study, the investigators collected data on real life forcible
entry in a building scheduled for demolition. Two male investigators, one outfitted in
the entire fire fighter turnout gear except the SCBA, performed forcible entry on
various entrances and doorways in the building. The investigators found that the
number of swings needed to complete the forcible entries averaged approximately 10
swings (range 2 to 25 swings).
It is desirable to develop a simulated forcible entry test that is legally and
scientifically defensible and is an acceptable physical standards test. It may be argued
that the forcible entry test is the least realistic representation in the circuit, so it is
crucial that this task be independently validated. The majority of the other circuits in
the literature have been designed as a test of physical capability during the entry
selection process for new recruits. On the other hand, the present circuit is designed
as a maintenance test and a training tool. The overall purpose of this substudy was to
examine the validity of the forcible entry test that is part of the circuit (Pelot, Dwyer,
Deakin & McCabe, 1996). There were two specific objectives for the study. Objective
One was to determine if hitting the tire was similar to hitting a structure found in real
life. The comparisons between hitting the reinforced structure and hitting the tire were
warranted because it was evident from studies completed by Misner et al. (1987) and
72
Gledhill and Jamnik (1992a) that fire fighters must strike solid and reinforced
structures. Objective Two,was to establish which parameters were appropriate for the
simulated forcible entry test (i.e. which distance to move the tire and which hammer
weight to use).
7.2 Methods:
7.2.1 Subjec&
Twenty male CF fire fighters from 12 Wing Shearwater in Nova Scotia
volunteered and gave informed consent to participate in the study. Complete
anonymity was ensured during this study and all subjects were free to withdraw at any
time. Any potential subjects with orthopaedic problems, back injury, and/or
neuromuscular illness were excluded from this study. The mean age of the subjects
was 35.8 years (range 29 to 46 years) with an average service time with CF of 16.9
years (range 9 to 29 years) and an average time as a CF fire fighter of 12.2 years
(range 4 to 27 years).
. Fxpenmen tal Setuos
To validate the simulated forcible entry test, the investigators had to
demonstrate that it was very similar to tasks completed by fire fighters during real life
forcible entry. The validation was completed in two stages: (1) comparing a reinforced
structure to real life forcible entry; and then (2) comparing hitting the tire to hitting the
reinforced structure.
73
Two experimental setups were used during the testing; first a reinforced
structure was designed to represent a realistic structural element. This structure would
allow fire fighters to strike a solid object to provide them with a comparison reference
for the tire. This reinforced structure also allowed the investigators to compare subject
performance characteristics: hammer speed prior to impact, rebound after impact, pull
back speeds, completion times, and physiological changes in terms of heart rate. The
reinforced structure was built using 2.5 cm plywood with the front surface fortified with
two layers of plywood. The inside of the structure was reinforced with Pisa II concrete
blocks and layers of 3.8 cm by 8.9 cm lumber. Two layers of 0.25 cm thick hard rubber
were placed on the contact surface of the structure to act as a target.
The second experimental setup was the simulated forcible entry test from the
circuit. A large 71 cm wide truck tire, weighing 105 kg (including 28 kg of sand bags)
was placed on a plywood table top. The sandbags were placed in the rim of the tire to
add mass to increase the difficulty of the task, as well as to give the tire more rigidity
and stability when struck. The height of the centre of the target area for the reinforced
structure and the tire was 92 cm from the floor.
223 Exoerimental Procedures
The subjects completed all of the eight forcible entry tasks and six one page
questionnaires for this study (refer to Table 16). The first four tasks were designed to
meet Objective One, whereas the last four tasks were designed to fulfill Objective Two.
The eight tasks were divided into two sets: SET 1 involved completing tasks 1 to 4 and
questionnaires 1 and 2; SET 2 involved completing tasks 5 to 8 and questionnaires 3 to
74
6. Half of the subjects were assigned randomly to complete SET 1 before SET 2, and
the other half were randomly assigned to complete SET 2 before .SET 1. Within each
SET the subjects were randomly assigned a task order. The total time requirement for
each subject was approximately three hours (one and a half hours on two different
days). There was a two day break between SETS and this provided a sufficient period
’ of time for the subjects to rest and fully recover.
Table 16: Summary of the parameters for the eight tasks used in the forcible entry substudy
SET Task Hammer used Target Goal Q
1 1 4.54 kg sledge R. S.’ 10 Swings #l
2 5.60 kg rubber R. S: 10 Swings N/A
3 4.54 kg sledge Tire 10 Swings #2
4 5.60 kg rubber ,Tire 10 Swings N/A ----------------__---------------------.---------------------------------------------------,
2 5 4.54 kg sledge Tire 3ocrn #3
Note: l R.S. = reinforced structure
For the first four tasks the subjects struck the reinforced structure or the
weighted tire vigorously 10 times with the 4.64 kg sledge hammer and 5.60 kg hard
rubber tip sledge hammer swinging as hard and as quickly as possible for all swings.
75
The subjects were asked not to swing wildly but work in the same manner as if they
were fighting a fire. Following this task, the subjects completed the appropriate
questionnaires regarding the perceived exertion of hitting the reinforced structure.
The last four tasks represent variations of the simulated forcible entry test from
the circuit. For the tasks, the subjects used the 4.54 or 5.60 kg sledge hammer to
strike the tire until it moved the prescribed distance. All of the distances were marked
on the table with a visible line and the investigator called out to the subjects to stop
swinging when they had crossed the line. Following each task the subjects completed
the appropriate questionnaire regarding the perceived exertion of hitting the tire.
7.2.4 Protocot
Prior to arrival, the subjects were asked not to eat or drink beverages containing
caffeine for at least two hours before testing. The subjects were also to refrain from
drinking alcoholic beverages and exercising for six hours prior to testing (Appendix C).
All subjects wore standard issue fire fighter turnout gear, including the helmet and
shield, coat, coveralls, boots, gloves, and the SCBA. The subjects wore shorts and a
short-sleeved shirt under their turnout clothing. The total mass of all of the turnout
gear was approximately 15 kg. The subjects brought their own fire fighting turnout gear
to ensure proper fit and safety.
When the subjects arrived they were connected to a Polar Electra Vantage XL
heart rate monitor and rested for five minutes while heart rate was determined. The
subjects then changed into their turnout gear. Immediately before testing, subjects took
four moderately forceful practice swings at the tire, two each with the 4.54 kg and 5.60
76
kg sledge hammers. Before completing each of the eight forcible entry tests, the
subjects pedalled a Monark cycle ergometer at 50 rpm with a light power output of 150
kpm/min (25 watts) for 2.5 minutes. This pedalling rate and power output, determined
through pilot testing, were selected to raise the heart rate and mimic the conditions that
had been observed during circuit performance. The subjects did not connect the SCBA
during cycling to conserve Oz. After the subjects cycled for 2.5 minutes, they walked 7-
10 metres to the test area, connected the mask to the 0, tank, and then completed the
scheduled test. Subjects were given a 10 minute rest between the tests to allow their
heart rates to return to resting level.
7.2.5 Data Collection
Five measurements were collected during the eight tasks in the study: (1) task
completion time, (2) number of swings, (3) heart rate, (4) speed of the hammer head,
(5) perceived exertion and similarities between the tasks. The time to complete each
task was recorded to the nearest tenth of a second. The number of swings for all tasks
were counted. In tasks l-4 where the number of swings were fixed at 10, the
investigator signalled to the subjects when to stop swinging.
The speed of the head of the hammer in metres per second was calculated
using two sets of photoelectric switches placed above and below the horizontal plane of
the motion of the hammer. The photoelectric switches were connected to an analog-to-
digital card (A/D) in a IBM compatible computer. This A/D card displayed a sync pulse
for each time the hammer handle passed through the plane of the set of photoelectric
77
switches. The width of the sync pulse represents the time for the hammer to pass
through each of the photoelectric beams. ,
The two sets of switches were placed 11 cm apart and the sender and receiver
unit for each set were placed 123 cm apart. Figure 9 displays a schematic
representation of the placement of the photoelectric switches. A computer program
was written to trigger the data collection routine when the hammer handle passed
through the first set of photoelectric switches. The second set of photoelectric switches
was used to calculate the speed of the hammer prior to impact. That same set of
sensors was then used to calculate the speed of the hammer coming off the tire or
reinforced structure, which was termed pull back speed #I. Finally, the triggering set of
photoelectric switches was used to calculate the last speed which was termed pull back
speed #2. The nearest set of photoelectric switches was placed 10 cm from the tire
and the reinforced structure.
The time required for the hammer handle to pass through the photoelectric
switches was calculated based on the sampling rate for the computer and the number
of samples collected during each swing. Measuring the width of the hammer handle,
the average speed of the hammer was calculated using: speed = distance + time.
78
Id Photoelectric Switches
Front View
Figure 9: Front view of the photoelectric switch setup to collect speed measures (forcible entry substudy)
The subjects’ mean heart rates were collected every five seconds and this was
completed during the 2.5 minutes cycling, the eight tasks and each of the 10 minute
rest periods (Figure 10).
79
Heart Rate @Pm)
185
170
155
140
125
110
PeakHeart
Mask to the SCBA 95
80
Tie (minutes)
Figure 10: A subject’s heart rate profile during the testing procedure highlighting the peak heart rate value (forcible entry substudy)
The peak heart rate during each forcible entry test was determined and
normalized to a percentage of maximum heart rate reserve (HRR) because this method
provides a better representation of the true physiological response of the subjects. The
calculation of HRR uses the subject’s estimated maximum heart rate, resting heart rate,
and peak heart rate. The subject’s HR,, was estimated for this study using 220 minus
the subject’s age (Heyward, 1991). The calculation of HRR is:
peak heart rate - resting heart rate HRR = (220 - age) - resting heart rate x100
80
The subjects completed the questionnaires after hitting the reinforced structure
and also after hitting the tire. The subjects’ perceptions of the tasks were recorded to
support the performance measures. There were four main topic areas covered in the
questionnaires: task difficulty, strength requirement, tiredness, and similarity between
tests.
6 Data Reduction and Analysis
The mean time (& standard deviation), speed and percentage of heart rate
reserve for all tasks, and the number of swings used in tasks 5 to 8 were summarized in
Table 18. A randomized complete block design ANOVA, with subjects considered to be
the blocks and with the tasks as a fixed effect and the subjects as a random effect was
completed on the performance data. Significant differences at p 5 0.05 were examined
post hoc using Duncan’s Multiple Range Test.
A day effect analysis was completed for the performance measures to determine
if the random assignment of the SETS and tasks was sufficient to reduce the order
effect. The day effect was analyzed using a three factor analysis of variance design
with incomplete information using a General Linear Model (GLM). Day and tasks were
fixed factors and subjects were random factors. Significant differences at p 5 0.05 were
examined post hoc using Duncan’s Multiple Range Test.
Responses to individual items in the questionnaire were summarized and then
grouped into the four main topic areas. The topic areas were summarized in tabular
form for all tasks and the mean, standard deviation, maximum and minimum values
were calculated for each task. Friedman’s Nonparametric ANOVA was used to test for
81
significant differences between the tasks for each topic area. Significant differences at
p s 0.05 were examined using Friedman’s post hoc comparison test.
7.3 Results:
The data were divided into two groups related to Objectives One and Two,
respectively. SET ‘I data included tasks ‘t-4 which had the subjects complete 10
swings with the 4.54 kg sledge hammer and the 5.60 kg hard rubber tip sledge hammer
on the reinforced structure and the tire. The main comparisons within SET 1 data were
between tasks 1 and 3 (reinforced structure versus tire with the 4.54 kg sledge
hammer) and tasks 2 and 4 (reinforced structure versus tire with the 5.60 kg hard
rubber tip sledge hammer). SET 2 data included tasks 5-8 which involved moving the
tire different distances along the table with a 4.54 kg sledge hammer. The main
comparisons to be made within SET 2 were between tasks 5,7 and 8 (changes in the
distance the tire was moved) and tasks 5 and 6 (a change in hammer weight). Another
comparison within SET 2 included tasks 5 and 6 which compared the use of the 4.54
and 5.60 kg sledge hammer to move the tire 30 cm.
An abbreviation was developed to help identify the various tasks in the tables
presented in the results. The label ‘RSlOLT” refers to 10 swings on the reinforced
structure with the lighter (LT) 4.54 kg sledge hammer. On the other hand, the label
‘RSIOHR” refers to 10 swings on the reinforced structure with the 5.60 kg hard rubber
(HR) tip sledge hammer. Finally, the label ‘TR30HV’ refers to hitting the tire 30 cm
with the heavier (HV) 5.60 kg sledge hammer.
82
7.3.1 Test of Normality
Prior to completing all of the statistical analysis on the data, a test of normality
was performed to verify that there were no irregularities in the data. The test of
normality was based on the correlation of the 2 scores versus raw data. The
straightness of the data reveals normality in the data, therefore a very high correlation
would be consistent with normality. H, was not rejected for normality in the current
study because the 2 scores versus raw data correlation did not fall below the critical
value. The critical value for this study was determined to be 0.9511 (N=20, a=O.O5).
There were high correlations for the Z scores versus raw data correlations which
revealed normality for all of the data (Table 17).
Table 17: Normality of the data (forcible entry substudy)
Variables Correlation
Heart Rate r = 0.983
Swings r = 0.984
Completion times r = 0.989
Pre-impact momentum r = 0.988
Pre-impact speed r = 0.990
Pull-back speed #l r = 0.997
Pull-back speed #2 r = 0.997
Table 18 summarizes the mean performance data for the twenty subjects in this
study. There was a general consistency among the data within SET 1; completing 10
swings on the reinforced structure had comparable results to completing 10 swings on
83
the tire. On the other hand, SET 2 data revealed that changing the distance to move
the tire resulted in differences in the performance data for the subjects.
Table 18: Mean performance data of the forcible entry task
Pre-impact Speed him I 7*g8 I 7.24
Pull-back Speed #1 1.55 1.30 Ws)
Pull-back Speed #2 1.66 1.45
(m/s)
Pre-impact 36.2 40.6 Momentum (kgmls)
l * Fixed test condition
3 4 5 6 7 8
TRlOLTTRlOHR TR30LT TR30HV TRlSLT TR45LT I I I I I
95.3 1 96.0 i 93.2 t 91.0 1 86.5 1 97.2
18.1 19.1 12.9 12.2 8.0 17.6
10" 10' 7.0 6.4 4.0 10.5
7.85 1 7.22 ( 8.60 1 8.20 ( 8.44 1 8.44
2.09 1.58 1.98 1.85 2.11 1.89
1.97 1.71 1.84 1.88 2.15 1.79
35.6 40.4 39.0 45.9 38.3 38.3
84
A summary of the analysis of variance (ANOVA) and the day effect analysis is
shown in Table 19. These results indicated that a significant difference in
performance could be measured with a change in parameters for the reinforced
structure and tire tests. The results for the day effect analysis indicated that there was
not a difference for the majority of the performance measures: There was a significant
day effect for HRR which might have occurred because of anxiety the subjects could
have been feeling on day one due to their unfamiliarity with the investigator and the
test surroundings. Since the subjects’ resting heart rates did not differ across days,
the difference in heart rates would have occurred during actions prior to and/or during
the testing. The results from Duncan’s Multiple Range Test are reported in Table 20.
This table identifies which tasks for each performance measure were significantly
different at p s 0.05.
Table 19: ANOVA and the Day Effect analysis (forcible entry substudy)
Performance Measure ANOVA Day Effect
HRR (%) F ,,,,=5.67, p<O.OOi* F cr,,n,=15.7, p<O.OOl*
Time (seconds) F i7.1331 =37.9, p<O.OOl’ F rr.,j2,=l.91, ~~0.170
l[Numberif Swings 1 F n.r331=171 .7, p<O.OOl l 1 F 1,.,321=2. 11 p>O.200
Pre-impact Speed (m/s) F ,,,,=16.4, p<O.OOl* F (,,,, ,,=0.78, ~~0.308
Pull-back Speed #l (m/s) F cr,,J,=9.38, p<O.OOl* F (,,rsz2,=0.31, ~~0.580
Pull-back Speed #2 (m/s) F ,,,,sj=4.77, p<O.OOl* F (,,r,z2,=4.09, ~~0.051
Pre-impact Momentum F (7,,13,=25.1, p<O.OOl* F cr,r32,=l.29, p SO.259 (kgm/s)
l Significant Difference
85
Table 20: Summary of Du?can’s Multiple Range Test (forcible entry substudy)
Set 1 Set 2 Task 1 2 3 4 5 6 7
Performance RSlOLT RSlOHR TRlOLT TRlOHR TR30LT TR30HV TRl5Ll Measure
HRR (%) - m - 1 ,ZW
Time (set) L w 1,2,3,4 1,2,3,4 1,2,3,4,5
Number of e 56 Swings
Pre-impact 1 2 183 12,W 2,4,5 1 ,&W Speed (m/s)
Pull-back Speed - 2 182 1,2,3 1,2,4 1,2 1,2,4 #l (m/s)
Pull-back Speed - - 1,2 - 1,2,3,4 1,2,3,4,5 1,3,4,6 #2 (m/s)
Pre-impact 1,2,3,4 1,2,3,4,5 1,3,4,6 Momentum (kg m/s)
7.3.2 Questionnaire Analysis
The questionnaire data were reduced to mean values and summarized for each
task and for each topic area. Figure 11 provides a graphical representation of the
summarized means for all tasks and topic areas. Referring to Figure 11, the subjects
displayed a tendency of responding near the average score of ‘4” or just above for task
difficulty, tiredness and similarity. In order to adequately determine if the tasks were
viewed to be different, a nonparametric analysis was completed for each topic area. A
Friedman test of score by task, blocked by subject was completed using the
questionnaire data concerning task difficulty, strength requirement, tiredness, and
86
7.00
6.00
5.00
4.00
3.00
2.00
1.00
-+-Difficulty -B-Strength --t-Tiredness ,+Similarity
Task Task Task Task Task Task 1 3 5 6 7 8
Task Number
Figure 11: A graphical representation of the summarized questionnaire data for all tasks and each topic area (forcible entry substudy)
similarity (Table 21). The results from the Friedman test revealed no significant
differences in scores across tests within any of the topic areas.
Table 21: Friedman’s Nonparametric ANOVA for the questionnaire data (forcible entry substudy)
i F. 1 df i D
Task Difficulty 9.61 5 0.090
Strength Requirement 4.64 5 0.461
Tiredness 4.64 5 0.461
Task Similaritv 4.97 5 0.420
07
7.4 Discussion:
. . 7.4.1 ObWve One .
As hypothesized, hitting the tire was not significantly different to hitting the
reinforced structure in terms of HRR, completion times, pre-impact speeds and pre-
impact momentums. These measures were equivalent when the subjects completed 10
swings on the reinforced structure and on the tire (tasks 1 & 3 with the 4.54 kg sledge
hammer versus 2 & 4 with the impact hammer, respectively). The results reveal that
the subjects were being physically challenged during the 18.1 to 19.1 seconds required
to complete the tasks. Even though the subjects rated the tasks as moderately
challenging, the physiological response of 93.2 to 96.0 % of HRR indicated that the
subjects were exerting more strenuous effort than that perceived. The fire fighters may
have not reported that they were being heavily challenged because they are expected
in the fire fighting profession to perform such tasks without difficulty.
During this study, there was not a perceived difference between hitting the
reinforced structure (tasks 1 and 3) and hitting the tire (tasks 2 and 4). The subjects
scored the tasks to be not significantly different in terms of difficulty, strength
requirement, tiredness, and similarity. For the most part, the subjects scored the tasks
near the mean (i.e. 4.0) which would be expected when administering questionnaires
unless the subjects have a strong opinion for the topic.
7.4.1 .I . . .
Mmmces between the hitma the t ire and h . ittina the reinforced structure
Hitting a tire may be perceived to be different from hitting a reinforced structure
because they are physically and visually different materials. During the circuit
88
development testing completed by Deakin, Stevenson, Pelot and Wolfe (1994) the
investigators asked the subjects to verbally provide their perceptions of hitting the tire ,
after completing the test. Hitting the tire was perceived as less realistic than striking an
actual structure like a door or door frame, but the subjects could not explain in detail
what the differences were. Conversely, the subjects did believe that both tasks were
challenging and both required effort.
The only significant differences between hitting the tire and hitting the reinforced
structure in the current study were the rebound and pull-back speeds. Due to the
rubber properties of the tire, hitting it caused a higher rebound speed when compared
to the reinforced structure. The fire fighters mentioned that there was a large rebound
when striking the tire. Perhaps the subjects might have benefited from the tire rebound,
thus allowing them to swing faster and decrease the time to completion time compared
to hitting the reinforced structure. In fact, there was no decrease in completion time
and the investigators speculate that the performances on the tire and the reinforced
structure were similar because the extra effort needed to control the hammer after it
rebounded off the tire negated the possible benefits from the rebound energy.
Comments from the majority of the subjects indicated that a greater effort was required
to control the hammer after it rebounded off the tire before they could initiate another
swing.
Despite the differences when comparing the data for the reinforced structure and
the tire, it was evident that they were very similar in the majority of measures. The
inherent differences in the properties of the reinforced structure and the tire caused
89
differences in rebound and pull-badk speeds for the subjects. Based on this
information, the investigators concluded that the reinforced structure and the tire were
very comparable tasks. Therefore, Objective Two concerning the appropriate
parameters for the simulated forcible entry test could be discussed.
. . 7.4.2 Ob!ectlve Two
This objective was divided into two parts. The first tested whether the 30 cm
distance to move the tire for the test was a suitable distance, and the second tested
whether the standard issue 4.54 kg sledge hammer was an acceptable hammer for the
task. To investigate the effect of altering the distance to move the tire on the measured
outcomes, distances of 15 cm (task 7) 30 cm (task 5) and 45 cm (task 8) were
compared. The data for moving the tire 15 cm showed that the task did not adequately
challenge the subjects. Since moving the tire 15 cm was very short in duration (mean
8.0 set; range 4.4-12.5 set), it did not force the subjects to take many swings(mean 4.0
swings; range 3.0 - 7.0) and did not show a sufficient heart rate response (86.5Or6
HRR). Some of the subjects described the test as “too short” and “too easy” and stated
that they really were not challenged.
The purpose of the circuit was to physically challenge the subjects and moving
the tire 30 cm was successful in doing this. When the subjects moved the tire 30 cm
there were significant increases in mean completion time (12.9 seconds), number of
swings (7.0), and HRR (93.2Oh) when compared to moving the tire 15 cm. Comparison
of the tasks in terms of pre-impact speed verified that they were swinging equally fast
during the tasks, since the pre-impact speeds were not significantly different. The
90
average heart rate response when moving the tire 30 cm was not at a critical level (i.e.,
average response of all the subjects was < 100% HRR) but some of the subjects were
at greater than lOOoh of predicted maximal HRR during all of the tests (reaching a
maximum value of 113%). The data for moving the tire 45 cm revealed a significant
increases from 30 cm in terms of completion time (17.6 seconds) and number of swings
(10.5) but not in HRR response (97.2%). The significant increase in task duration only
caused a slight increase in physiological response.
When the subjects were required to move the tire 45 cm, the motion of the
swings changed because the subjects had to move the position of their feet as the tire
moved closer to the 45 cm mark on the table. This was confirmed by comments from
subjects in the open-ended section of the questionnaire. The 30 cm distance allowed
the subjects to complete the task with their feet in one location and maintain the same
swing motion throughout. As the tire moves along the table nearer the 45 cm mark,
subjects mentioned that it becomes more difficult to avoid hitting the table top. Thus
the subjects had to develop the skill to complete the task without hitting the table.
To determine whether the 30 cm task was more suitable than the 45 cm task,
one must recall that the purpose of the entire circuit was to physically challenge the
subjects during each test. As previously mentioned, the 15 cm task did not seem to
challenge the subjects, whereas the 30 cm task did. On the other hand, the 45 cm task
appeared to be very physically challenging for the subjects because the mean value for
HRR was 97.2% and 9 of the 20 subjects worked at great than 100% of their predicted
maximal HRR (with a maximum of 117%). Since the simulated forcible entry test is the
91
sixth task in the circuit, with the fire fighters working at 97.2% of their predicted maximal
HRR, there would be a potential for the subjects to become fatigued and not finish the
last three tests in the circuit.
In the context of the circuit, when a subject knows that he or she is weaker in
one test, that person is able to plan the completion of the circuit by making up for lost
time elsewhere. This would mean that if the forcible entry test is the hardest test to
complete, he or she might try and move more quickly on the ladder climb to
compensate for the slower forcible entry task. If the SFET distance were set at 45 cm,
relatively few subjects could use the forcible entry task as a method to make up time
because it was too physically challenging. In most respects the 45 cm distance did not
provide an appreciable advantage over the 30 cm distance in terms of physiological
response or performance. Based on all of the information, it seems appropriate to use
the present 30 cm distance for the SFET.
The next part of Objective Two was to determine if the standard issue 4.54 kg
sledge hammer was the more appropriate hammer to use compared to the 5.6 kg
sledge hammer. There were no significant differences for the majority of the measures
between the two hammers (HRR, completion time, number of swings, pull-back speeds
and perceptions). The only differences between the two hammers were their pre-
impact speeds and pre-impact momentums but these did not correspond to a difference
in performance. The subjects’ ability to swing the 4.54 kg hammer more quickly with
less momentum was similar to swinging the 5.6 kg hammer more slowly with a higher
92
momentum. Based on all of the data it seems appropriate to conclude that the
standard issue 4.64 kg sledge hammer allowed the subjects to complete the 30 cm task
with similar performances compared to the 5.6 kg sledge hammer. Therefore, the use
of the 4.64 kg standard issue hammer would be appropriate for the 30 cm task, and it is
not necessary to further consider the 5.6 kg sledge hammer.
. 7.4.3 Comparison To Previous R esearch
It was important to compare the methodology and results of the current study to
the relative merits of previous simulations because the experimental setups of the
earlier research varied so dramatically. However, this comparison was difficult
because most of the previous studies did not report the means, standard deviations,
and ranges for completion times and heart rates for completing their tests. From the
studies that did report mean completion times, the results of the present study were
consistent with Misner et al. (1987) and Davis (1995). The mean completion times for
those tests were 9.4 and 10.0 seconds respectively. However, there were simulated
tests which reported much longer completion times. Davis et al. (1982), Schonfeld et
al. (1990) and Louhevaara et al. (1994) reported mean completion times of 1 SO, 1.09,
and 2.00 minutes respectively, arising from very different test parameters.
In terms of the real life forcible entry data reported by Gledhill and Jamnik
(1992a), the results of the current study were consistent with their average maximum
heart rates but were not as comparable to their completion times. The average
maximum heart rate for real life forcible entry was 164 bpm versus 166 bpm in this
study, and the average completion time for real life forcible entry was 46 seconds
93
versus 12.9 seconds in this study. The difference in completion times could have been
primarily due to differences in the starting and finishing of data recording.
7.5 Conclusion:
The current study has shown that tasks completed on the tire were comparable
to tasks completed on the reinforced structure in the majority of measures. The
physiological response, performance measures, and perceived exertion and perceived
similarities were equivalent when the subjects completed similar tasks on the reinforced
structure and on the tire.
Varying the task parameters can control the physical effort needed by the
subjects. Increasing the distance for the tasks caused a significant increase in
percentage of heart rate reserve and in the number of swings required. Therefore,
distance can be a suitable control for achieving a desired range for a percentage of
heart rate reserve because of the response range displayed by the subjects.
The current study has also shown that tasks completed on the tire were
comparable to tasks completed on the reinforced structure in the majority of measures.
The parameters for the SFET that were determined to be most appropriate were to
move the tire 30 cm and use the 4.54 kg sledge hammer.. Based on all of the
information presented in this study, the investigators have demonstrated that the
parameters for the SFET of the circuit make it a bona fide test of a real life task that fire
fighters must complete in their job.
94
. Chapter 8:
\ RECOMMENDATIONS
8.1 Introduction:
The goal of this research project was to develop a valid minimum physical
fitness maintenance standard for CF and DND fire fighters. The work contained within
this report represents an undertaking consistent with the rules governing the
establishment of a bona fide occupational requirement (BFOR), as set out by the
Government of Canada (1988). The ERG makes the following recommendations with
respect to the selection and implementation of a single performance objective for all
active fire fighters under the jurisdiction of CFFM.
8.2 Determination of the Performance Objective:
Based on the analyses contained within the main data collection, the ERG
recommends that a standard of 8:00 minutes on the circuit be set as a cut off score for
the physical maintenance test. This performance objective falls within one standard
deviation of the grand mean of 7:46, as well as the mean performance times for all
fitness rating categories. The average performance of the two subgroups of women fire
fighters (professional 20 - 39) with adequate sample size on which to make inferences,
also falls within one standard deviation of the 8:00 minute criteria. It is a performance
objective that, in the view of ERG, will provide a moderate challenge for the young,
aerobically fit fire fighters, while representing an attainable objective for older, or less
aerobically fit individuals.
95
8.3 Implementation Schedule: -
Based on the analysis of data collected on 226 fire fighters (CF, DND, and
professional women), it is anticipated that between 2942% of this population would not
achieve the standard (see Figure 4). It is acknowledged that, initially, certain
individuals may have difficulty achieving that performance time, and we suggest the
gradual phase-in of this 8:00 minute standard. With physical fitness training, and the
opportunity to practice the circuit, it is anticipated that more individuals will be able to
meet the standard. Fire fighters will require some time for physical training, and to
accept the new maintenance test. The following recommendations are made with
respect to the implementation of the maintenance test:
8.3.1 A three year implementation period should be adopted, whereby the 8:00 minute
standard is accepted, but that a grace period be provided in the first two years:
Year One: 8:00 minutes + 30 second grace period (8:30)
Year Two: 8:00 minutes + 15 second grace period (8:15)
Year Three: 8:00 minutes (8:00)
8.3.2 Initially, there should be no job sanctions based on an individual’s inability to
meet the standard. Rather, any individual not meeting the standard should be
required to participate in a mandatory physical fitness training program, and
retested 6 months later, to provide feedback to the individual, and to the
administrators of the training program.
96
8.4 Testing Schedule and Protocbl:
The following recommendations regarding the test protocol and testing schedule are
provided:
8.4.1 Prior to participation, all fire fighters taking part in the physical maintenance test
program be required to complete a health appraisal questionnaire, and have
resting heart rate and blood pressure assessed, as per ACSM (1995) guidelines.
8.4.2 All fire fighters should be provided with the opportunity to practice the circuit at
various times throughout the year. This may be accomplished by arranging
practice days at each fire hall, with the circuit being set up by trained individuals
(to ensure standardization of the circuit tasks).
8 4.3 Use of the assist device (piece of rope) made available in the Women’s
Substudy should be permitted, within the confines of appropriate rescue
technique.
8.4.4 For the annual maintenance test, all candidates should complete a dry run in full
turnout gear no more than 48 and no less than 24 hours preceding the actual
test.
8.4.5 For the actual test, the circuit must be set up on a surface which falls within the
guidelines of this report (Appendix B), and that all task parameters (mass,
distance, and equipment) are standardized. Any deviation from this protocol
may have a significant impact on the performance times of the circuit, and thus
on the candidates themselves, particularly in terms of the consequences of a
poor performance.
97
8.4.6 For the actual test, only trained and qualified staff should administer the test
protocol. ,
8.5 Remedial Assistance:
For all fire fighters who are not successful in meeting the standard for circuit
performance, the following recommendations are made:
8.51 Unsuccessful fire fighters should be directed to immediate physical fitness
training in an effort to improve their performance on the circuit. It must be
emphasized that the standard for the circuit has been designed and developed
to improve the fitness levels of all fire fighters in the CF and DND, and not as a
reason to terminate these individuals. Every effort should be made to ensure
that all fire fighters are provided with the opportunity to succeed at the circuit.
8.5.2 This remedial physical fitness program should be administered and supervised
by qualified personnel. Individuals who enter this program should be provided
with the opportunity to practice the components of the circuit, in addition to
fundamental training activities and exercises. After a six month remedial training
period, the individual should be retested on the circuit, following the same
protocol as described above.
98
8.6 Retest:
8.6.1 If a fire fighter fails to meet the standard by less than 15 seconds, it is
recommended that they be provided with the opportunity for retest within six
months.
8.6.2 If the fire fighter fails to meet the standard by more then 15 seconds, it is
recommended that they be required to participate in a mandatory physical
fitness training program as outlined above.
8.7 Sanctions:
8.7.1 To enable fire fighters the time required to improve their fitness levels and to
provide the time to familiarize themselves with the circuit and to accept the
maintenance test, it is recommended that there be no career sanctions against
any fire fighter who fails to meet the standard in years one and two, other than to
require them to participate in a physical training program.
8.8 Incentives:
It is the opinion of the Ergonomics Research Group that many fire fighters are
motivated by the development of this maintenance test, which is perceived to
accurately reflect job demands. There is also support for improving the fitness levels of
CF and DND fire fighters. In order to encourage the fire fighters’ interest in the circuit,
it is suggested that standardized training programs be provided to fire fighters in an
effort to improve their performance on the circuit.
99
Chapter 9:
LITERATURE CITED
Adams, T.D., Yanowitz, G., Chandler, S., Specht, P., Lockwood, R., 8 Yeh, M.P. (1986). A study to evaluate and promote total fitness among fire fighters. Journal of Sports Medicine, 26, 337-345.
. American College of Sports Medicine. (1995). Guidelines for Exercise Test ina and _ . .
Prescnptm 5th ed. Philadelphia: Lea & Febiger.
American College of Sports Medicine. (1991). Guidelines for Fxercise Testina and Prescription, 4th ed. Philadelphia: Lea & Febiger.
Astrand, P.O. 8 Rhyming, I. (1954). A nomogram for calculation of aerobic capacity (physical fitness) from pulse rate submaximal work. Journal of Applied . Physloloay , Z, 218-221.
Astrand, P.O. & Rodahl, K. (1986). Jextbook of Work Phvsiolocy. (3rd ed.) New York: McGraw-Hill Book Company.
Bahrke, M.S. (1982). Voluntary and mandatory fitness programs for fire fighters. The Phvsician and Sportsmedicine, 1 O(8), 126-l 32.
Barnard, R.J., Gardner, G.W., & Disco, N.V. (1976). lschemic heart disease in fire fighters with normal coronary arteries. Journal of Occuotional Medicine, j& 818-820.
Bell, D.G. & Allen, C.L. (1983). An Evaluation of the Standard Test of Fitness of CF Male Personnel. DCIEM Reoort No. 83 s B R 08.
Bell, D.G. & Jacobs, I. (1986). Relationship of Field Test Battery to Laboratory Tests of Muscular Strength and Endurance, and Maximal Aerobic Power. DCIEM_ Reoofl No. 86 --. R 22
Ben-Ezra, V. & Verstraete, R. (1988). Stair climbing: An alternative exercise modality for firefighters. Journal of Occupational Medicine, a, 103-105.
Brooks, D. J. (1991) ‘SCBA training drill’ Fire Emeraency, 13-l 4.
100
Brownlie, L., Brown, S., Diewert, G.; Good, P., Holman, G., Laue, G., & Banister, E. (1985). Cost-effective selection of fire fighter recruits. Medicine and Scia . Jn Sports and Exercise, 17(6), 661-666.
Bruno, J.F. (1988) ‘Fire fighters physical test exam #7022’ New York City Fire Department.
Byrd, R. & Collins, M. (1980). Physiologic characteristics of fire fighters. Ameria . Correcttve Therapv Journal , &j.(g, 106-109.
Cady, L.D., Bischoff, D.P., O’Connell, E.R., Thomas, P.C., & Allan, J.H. (1979). Strength and fitness and subsequent back injuries in firefighters. Journal of Occupational Medicine, u, 269-272.
Cady, L.D., Thomas, P.C., & Karwasky, R.J. (1985). Program for increasing health and physical fitness of fire fighters. Journal of Occupational Medicine, a, 110-114.
Caiouo, V.J., Davis, J.A., Ellis, J.F., Anus, J.L., Vandagriff, R., Prietto, C.A., & McMaster, W.C. (1982). A comparison of gas exchange indices used to detect t:7e anaerobic threshold. Journal of Applied Phvsioloav, 5315), 1184- 1189.
Considine, W., Misner, J.E., Boileau, R.A., Pounian, C., Cole, J., & Abbatiello, A. (1976). Developing a physical performance test battery for screening Chicago fire fighter applicants. Public Personnel Management, JanlFeb, 7-l 4.
Cooper, K.H. (1968). A means of assessing maximal oxygen intake. Journal of the American Medical Association, 203(13), 135-l 38.
Davalos, D. (1972). Smoke eaters’ heart disease. Fire Command, &, 41-46.
Davis, P.O. & Dotson, C.O. (1987). Physiological aspects of fire fighting. Fire Technolooy, a, 280-291.
Davis, P.O., Dotson, C.O., & Santa Maria, D.L. (1982). Relationship between simulated fire fighting tasks and physical performance measures. Medicine and Science in Sports and Fxercise, 14(l), 65-71.
Davis, P.O., Dotson, C.O., & Santa Maria, D.L. (1978). The physical requirements of fire fighting, Fire Command I m, 36-38.
101
Davis, P.O. & Star& A.R. (1992). Excess body fat - not age viewed as a greater culprit in the fitness decline. Fire Fnaineering, u, 33-37.
Davis, P. (1995) ‘The American Fire Fighter Combat Challenge’. ESPN TV Program.
Deakin, J. , Stevenson, J. , Pelot, R. , & Wolfe, L. (1994). DND Firefiahtina Circuit . . Development. h-mm Rood Ergonomics Research Group, Queen’s University, Kingston, Ontario.
. . . Department of National Defence. Canadian Forces Admrnrstratrve Order 50 1 - .
Department of National Defence. Canad ian . . .
Forces Admrnrstratrve Order 50 - 73 .
Department of National Defence. (1981). CF FXPRES Operations Manual.
Doolittle, T.L. (1979). Validation of phvsical requirements for firefiahters. (un pub)
Dotson, C.O. & Caprarola, M.S. (1984). Maximal oxygen intake estimated from submaximal heart rate. British Journal of Sports Medicine, 18(3), 191-194.
Faria, I.E. & Faria, E.W. (1991). Effect of exercise on blood lipid constituents and aerobic capacity of fire fighters. The Journal of Work Medicine and . Ph\rslcal Fitness ,3111);75-81.
Fitness and Amateur Sport. (1986). Canadian Standardized Test of Fitness (CSTF) Ooerations Manual. (3rd ed.) Ottawa.
Fitness and Amateur Sport. (1981). Canadian Standardized Test of Fitness (CSTF) . Ooeratrons Manual. (1 st ed.) Ottawa.
Gilman, W.D. & Davis, P.O. (1993) Fire fighting demands aerobic fitness. NFPA Journal, Mar/&, 68-73.
Gledhill, N. & Jamnik, V.K (1992a). Characterization of the physical demands of . firefighting. Canadian Journal of Sport Sciences , 17(3), 207-213.
Gledhill, N. & Jamnik, V.K (1992b). Development and validation of a fitness screening protocol for firefighter applicants. Canadian Journal of Sport Sciences, 17(3), 199-206.
. . . Government of Canada (1988). Bona fide Occupational Requrrement Policy .
Ottawa: Canadian Human Rights Commission.
102
Government of Canada. (1985). Canadian Human Riahts Ad. Ottawa: Canadian Human Rights Commission.
Government of Canada. (1’982). Canadian Human Rqhts Act. Bona Fide . . .
. . . . Occypatronal Rewnt Gurdelrna. Commission.
Ottawa: Canadian Human Rights
Green, J.S. & Crouse, S.F. (1991). Mandatory exercise and heart disease risk in fire fighters: a longitudinal study. international Archives of Occupational ati . mHealth, B, 51-55.
Guidotti, T.L. (1992). Human factors in firefighting: Ergonomic-, cardiopulmonary-, . and psychogenic stress-related issues. jnternatlonal A rchives of . Occupational and Environmental Health , lfi4, i-12.
. . Heyward, V. (1991). Advanced Fit ess Assessments and Exercise Prescnotron (2nd ed.). Illinois: Human Kiietics Books
Hilyer, J.C., Brown, K.C., Sirles, A.T., & Peoples, L. (1990). A flexibility intervention to reduce the incidence and severity of joint injuries among municioal firefighters. Journal of Occuoational Medicine, a, 631-637.
Horowitz, M.R. & Montgomery, D.L. (1993). Physiological profile of fire fighters compared to norms for the Canadian population. Canadian Journal of Public Health, u, 50-52.
Horsfield, K., Guyatt, A.R., Cooper, F.M., Buckman, M.P., & Cumming, G. (1988). Lung function in West Sussex firemen: A four year study. British Journal of industrial Medicine, 4, 116-l 21.
Hughes, M.A., Ratliff, R.A., Purswell, J.L., & Hadwiger, J. (1989). A content validation methodology for job related physical performance tests. Pub& Personnel Manaaement, i, 487-504.
Jamnik, V.K. & Gledhill, N. (1992). Development of fitness screening protocols for physically demanding occupations. Canadian Journal of Sport Sciences, 17(33,222-227.
Jette, M. (1979). A comparison between predicted V02 Max from the Astrand procedure and the Canadian Home Fitness Test. Canadian Journal of . led Sport Science, m, 214-218.
103
Jette, M., Campbell, J., Mongeon, J., & Routhier, R. (1976). The Canadian Home Fitness Test as a predictor of aerobic capacity. Canadian Media . .
socratlon Journal, m,680-682.
. . . Lamb, D.R. (1984). Phvsioloov of Exercrse. Reponses and Adaptations . (2nd ed.) New York: MacMillan Publishing Company.
. Lee, S.W. (1991). Task related ae obic and anaerobic ohvs ical fitness
Ph.Dr thesis, University of Alberta. standards
for the Canadian Am,
Lemon, P.W.R. & Hermiston, R.T. (1977). The human energy cost of fire fighting. Journal of Occupational Medicine, m, 558-562.
Louhevaara, V., Smolander, J., Tuomi, T., Korhonen, O., & Jaakkola, J. (1985). Effects of an SCBA on breathing pattern, gas exchange, and heart rate during exercise. Journal of Occupational Medicine, 27(3), 213-216.
Louhevaara, V., Soukainen, J., Lusa, S., Tulppo, M., Tuomi, P., & Kajaste, T. (1994). Development and evaluation of a test drill for assessing physical work capacity of fire fighters. Jnternational Journal of Industrial EraonomicS, n, 139-l 46.
MacDougall, J.D., Wenger, H.A., & Green, H.J. (1991). Phvsiolooical Testina of the High Performance Athlete, (2nd ed.) Champaign, IL: Human Kinetics.
Margaria, R., Aghemo, P., & Limas, F.P. (1975). A simple relation between performance in running and maximal aerobic power. Journal of Applied Phvsiology, w, 351-352.
Maud, P.J. & Shultz, B.B. (1989). Norms for the Wingate anaerobic test with comparison to another similar test. Research Quarterlv for Exercise and sport, @Jo, 144-l 51.
McArdle, W.D., Katch, F.I. & Katch, V.L. (1991). Exercise Phvsioloav: Fne gy, . . utntlon. and Human Performance . (3rd ed.) Philadephia: Lea & Febiger.
Misner, J.E., Boileau, R.A., & Plowman, S.A. (1989). Development of placement tests for firefighting: A long-term analysis by race and sex. &plied Ergonomics, m, 218-224.
Misner, J.E., Plowman, S.A., & Boileau, R.A. (1987). Performance differences between males and females on simulated firefighting tasks. Journal of Occuoational Medicine, 29(10), 801-805.
104
Myles, W.S., Brown, T.E., & Pope, 3.1. (1980). A reassessment of a running test as a measure of cardiorespiratory fitness. fiaonomics, 23(6), 543-547.
O’Connell, E.R., Thomas, P.C., Cady, L.D., & Karwasky, R.J. (1986). Energy costs of simulated stair climbing as a job-related task in fire fighting. Journal of
. upattonal Medicine, 2&&, 282-284.
Pelot, R.P., Dwyer, J.W., Deakin, J.M. & McCabe, J.F. (1996). The validitv of a simulated forcible en@ test for fire f ahters Working paper IE96-01. Department of Industrial Engineering, TUNS, Halifax, Nova Scotia.
Pelot, R. P. , Klatt, J. W,. & Lachance, C. J. P. (1994). Preliminary evaluation of forcible entry in fire fiam Canada, Kingston, Ontario.’
Internal report, Royal Military College of
Radford, E.O. & Levine, M.S. (1976). Occupational exposures to carbon monoxide in Baltimore fire fighters. Journal of Occuoational Med’cine, u, 628-632. I
Rasch, P.J. & Wilson, t.D. (1964). The correlation of selected laboratory tests of physical fitness with military endurance. Militarv Medicim, 129, 256-258.
Raven, P.B., Davis, T.O., Shafer, C.L., & Linnebur, A.C. (1977). Maximal stress test performance while wearing a self-contained breathing apparatus. Journal of Occupational Medicine, 19(17), 802-806.
Reischl, U., Bair, H.S., & Reischl, P. (1979). Fire fighter noise exposure. American jndustrial Hvoiene Association Jourd, 4, 482489.
Rogers, C.C. (1984). Firing up for fitness. The Phvsician and Sportsmed . . lclne,
l.20, 134-142.
Romet, T.T. & Frim, J. (1987). Physiological responses to fire fighting activities. Eurooean Journal of Applied Phvsioloqy, s, 633-638.
SAS Institute, Inc. (1985). SAS user’s guide: Statistics. Cary, NC: Author.
Saupe, K, Sothmann, M., & Jasenof, D. (1991). Aging and the fitness of fire fighters: The complex issues involved in abolishing mandatory retirement . ages. American Journal of Publrc Hea lth, m, 1192-l 194.
Schonfeld, B.R., Doerr, D.F., & Convertino, V.A. (1990). An occupational performance test validation program for fire fighters at the Kennedy Space . Center. Journal of Occupatronal Med icine, 32(7), 638-643.
105
Shephard, R.J., Cox, lvi., Corey, P.;& Smyth, R. (1979). Some factors affecting accuracy of Canadian Home Fitness Test scores. Canadian Journal of .
red Sport Science, m, 205-209.
Singh, M., Lee, S.W., Wheeler, G-D., Chahal, P., Oseen, M. & Courture, R.T. . (1991). Final Report on Developawd of Forces Mobile Command Army . . . Phwcal Fitness Fvaluatlon and Standa . .
rds for Field UnQ Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Alberta.
SkUldstrom, B. (1987). Physiological responses of fire fighters to workload and thermal stress. Eroonomics, 3O(lQ 1589-I 597.
Sothmann, M., Landy, F., & Saupe, K. (1992). Age as a bona fide occupational qualification for firefighting: A review of the importance of measuring aerobic power. Journal of Occupational Medicine, 34(l), 26-33.
Sothmann, M., Saupe, K, Raven, P., Pawelczyk, J., Davis, P., Dotson, C., Landy, F., & Siliunas, M. (1991). Oxygen consumption during fire suppression: Error of heart rate estimation. Eraonomics, 34(17), 1469-1474.
Sothmann, M.S., Saupe, K.W., Jasenof, D., Blaney, J., Fuhrman, S.D., Woulfe, T., Raven, P.B., Pawelczyk, J.P., Dotson, C.O., Landry, F., Smith, J.J., & Davis, P.O. (1990). Advancing age and the cardiorespiratory stress of fire suppression: determining minimum standard for aerobic fitness. Jiuman Performance, m, 237-258.
StatSoft, Inc. (1994). Statistica for Windows. Tulsa: Author.
Stevenson, J.M., Andrew, G.M., Bryant, J.T., Thompson, J.M., Lee,, S.W. & Swan, . . R.D. (1988). Development of MInImum Phvs ical Fitness Standa ds for the
. Canadian Armed Forces. Phase JU . School of Physical and HLatth Education and Department of Mechanical Engineering, Queen’s University, Kingston, Ontario, Canada.
Thoden, J.S. (1991). Testing aerobic power. In J.D. MacDougall, H.W. Wenger & H.J. Green (Eds.). Phvs
. ioloaical Testlna of the Hiah-Performan
(pp. 107-173). Champaign, III.: Human Kinetics Publishers, tncC e Athlete
Thomas, C.L. (1993). Taber’s Cvclopedic Dictionarlv, (17th ed). Philadelphia: FA. Davis Company.
106
Wilmore, J.H., Parr, R.B., Girandola, R.N., Ward, P., Vodak, P.A., Barstow, T.J., Pipes, T.V., Romero, G.T., 8 Leslie, P. (1978). Physiological alterations . . consequent to circuit weight training. Medicine and Science In Sports t
’ lOf2), 79-84.
Windle, 0. (1975). Physical agility tests used in Albuquerque Fire Department recruit selection process. Fire Enaineerinq, Mar, 41-43.
Wolfe, L.A., Walker, R.M.C., Bonen, A. & McGrath, M.J. (1994). Effects of pregnancy and chronic exercise on respiratory responses to graded exercise. Journal of Aoolred Phvsioloay, 76(5), 1928-l 936.
Wolfe, L.A., Cunningham, D.A., Davis, G.M. 8 Rechnitzer, P.A. (1978). Reliability of non-invasive methods for measuring cardiac function in exercise. Journal of Applied Phvsiology, 44(l), 55-58.
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APPENDICES
108
APPENDIX A: MOST COMMON AND DEMANDING TASKS FOR CF FIRE FIGHTERS
1. Perform tasks in hazardous environments wearing self-contained breathing apparatus (SCBA):
a) oxygen-generating breathing apparatus; b) positive-pressure breathing apparatus; c) negotiating the smoke maze wearing breathing apparatus.
2. Use and maintain fire department ladders: a) correctly carrying and raising a 7 m ladder; b) correctly carrying and raising a 12 m ladder as a member of a team; c) correctly climbing a 12 m ladder and applying a leg-lock at a height of at least 8 m.
3. Perform forcible entry practices: a) demonstrate the proper procedure for gaining access through doors, locked windows, walls, ceilings, roofs, and floors.
4. Participate in rescue operations during emergencies by operating the following equipment:
a) portable rescue saw; b) chain saw; c) engine generator set; d) hydraulic rescue kit; and e) power rescue tool.
5. Perform fire apparatus practices: a) operate a structural fire fighting vehicle connected to water sources; b) correctly perform a hydrant-to-fire lay of hose; c) open hydrants; and d) tighten couplings.
6. Perform the following search operations: a) room search; b) above ground search; and c) search and rescue in a smoke maze while wearing an SCBA.
7. Conduct rescues form buildings using the following methods: a) helping a victim to walk; and b) carrying a victim by seat carry, chair carry, lone rescuer lift and carry, bunker coat or blanket drag, and stretcher carry.
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8. Perform rescues using:. a) breathing apparatus; b) cordage; c) ladders; and d) rescue equipment.
9. Perform ventilation, salvage, and overhaul operations: a) use smoke ejector/exhauster; b) fold, throw, and roll savage cover; c) use mop-up kit; d) use clean-up kit; and e) apply water fog to expel gas and smoke.
10. Perform vehicle extrication: a) remove trapped casualty from a vehicle; b) gain access to vehicle through windows, doors, tops, and floors.
11. Perform aircraft fire fighting and rescue operations: a) apply foam, dry chemical, and halon using handline techniques; and b) casualty evacuation.
12. Fight structural fires: a) carry dry hoses and advance charged hoses; b) carry, raise, use, and lower fire fighting equipment; c) carry, raise, climb, and lower ladders, d) perform duties of hoseman, nouleman, rescue man, and salvage
man; e) direct water streams; f) conduct search and rescue operations; g) conduct ventilation operations; and I) perform forcible entry.
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‘APPENDIX B: CATALOGUE OF EQUIPMENT
Ladders:
I Physical Measurements
ladder length 4.44 m 7.8 m 12.1 m ’ 13.8 m
ma= NO 13.6 30.9 75 81.8
number of rungs 12 24 38 52
distance between 34.5 34.5 34.5 34.5 rungs (cm)
circumference of 10 10 10 10 rungs (cm)
number of extensions 0 2 3 3
rope diameter (cm) N/A 3.8 3.8 3.8
inside width (cm) 44.7 44.7-52.1 43.3-58.2 44.0-58.2
outside width (cm) 51.5 51.5-58.2 50.1-63.6 50.8-65.0
first step height (cm) 24.4 26.4 27.1 27.1
Task Measures
Extension forces N/A
Retraction forces N/A
Number of carriers 1
222-289 N 467-489 N N/A
222N 467-489 N N/A
2 (1 is possible) 2 from truck; 4 4 carry
fiotes; 1: with stabilizer poles Mass of rescue ladder is 15.9 kg
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Hoses, Couples, and Nozzles: .
Hose diameter
length (m)
uncharged mass (kg)
hydrant gate (kg)
hydrant bolt size (mm)
nozzle
’ Physical Measurements
100 mm 65 mm 38 mm
16.25 or 32.5 16.25 16.25
20.5 or 39.5 15.9 a.2
6.8
33
mystery nozzle 38 mystery nozzle 65 2W solid stream ml; 2.7 kg ml; 4.5 kg 6.8 kg
hose drag
torque to open hydrant
Task Measures
178 N (rolled) 236 N to start (pull rope/drag on ground)
267-311 N maximum (charged)
31 l-444 N I
Note; Mass of 44 mm hose is 7.7 kg
High Volume Hose Pull (Task 5): This task must be completed on a concrete slab floor (common to most CF fire
halls). The minimuq force to initiate movement of the 100’ length of 100 mm rolled hose was 189 N. During the performance of the circuit, the force required to initiate movement should be between 177.9 and 200 N (4045 Ibs of force). A 50’ length of 65 mm hose may be added in order to achieve the target force requirements.
l Measurement of the minimum force requirements was conducted using a Shimpo MF-100 force gauge. To measure the minimum force, the gauge was attached to the end of the 30.48 m length of rope, and pulled with a smooth motion until movement of the hose was initiated.
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Protective Clothing:
I Equipment t Mass (ka) 1
IC oat and liner (size 6x) I 4.1 I
Pants, boots and liner (size 6x) 6.4 I
I Helmet
I Mask
Boots 3.6 I 1 Tank (empty)
Tank (full)
Ultralite tank (full), harness, regulator, and mask
5.9
11.4
Fixture Heights:
Equipment Height from ground (m)
Running board 0.57
Top of chassis 1.73
Hose bed 2.25
Intake and discharge 0.41-0.65
Ladder down 1.3
Ladder up 2.06
Tail board to hose bed 1.52
Note; Ail measurements taken from ground level on a Spartan truck Over a dozen different truck types.
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Additional Measures:
Equipment I Mass (kg) I
2H gallons 12.3
Stoker stretcher (1.81 x 0.65 m) 9.1
Equipment Starting Force (N)
Jaws of Life power unit 467-489
3250 W Generator 245311
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. APPENDIX C: PRELIMINARY INSTRUCTIONS / TESTING ADVISORY
In order to achieve standaidization and ease of measurements, the following
instructions should be followed:
a) Dress Requirements: For the sub-maximal progressive step test, a t-shirt, shorts or
sweat pants, and running shoes are recommended. Full turnout gear and SCBA will be
required for both the walk-through and performance trial of the circuit.
b) Food: Do not eat for at least two hours prior to testing.
c) Beverages: Do not drink any caffeine beverage for two hours prior to testing, or
alcoholic beverages for six hours prior to testing.
d) Smoking: Refrain from smoking for two hours prior to testing.
e) Exercise: Refrain from exercise for six hours prior to testing.
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- APPENDIX D: INFORMED CONSENT FOR CIRCUIT
I, , author& the Ergonomics Research Group of Queen’s University, to administer and conduct a sub-maximal progressive step-test, and testing on circuit performance.
Prior to completing the progressive step-test, measurements of my resting blood pressure and resting heart rate will be taken. For the sub-maximal progressive step-test, I will be required to perform a series of 3 minute stepping sequences on a double 20.3 cm step tp a six-count musical rhythm with a progressive increase in tempo as set by a cassette tape. I will be started at an appropriate stage based on my age and gender. At the end of each 3 minute sequence, I will be stopped and my heart rate will be taken. Based on my post-exercise heart rate, the tester will ascertain whether I will be permitted to continue.
The circuit is designed to measure my physical abiities to perform fire fighter related physical performance tasks. These measures are performed in a circuit consisting of a one-arm hose carry, a 14 foot ladder carry and raise, a charged hose drag, a 24 foot ladder climb. A charged hose drag, a 24 foot ladder climb, a high volume hose drag, a forcible entry simulation, a victim drag, and a spreader tool carry. Instructions in regards to the conduct of each tasks within the circuit will be given to me prior to the start of the performance on the circuit. I will also be permitted a familiarization walk-through of the circuit. Since the circuit is a simulation of tasks performed at the scene of a fire, I will be required to wear my full turn-out gear and SCBA. During the performance of the circuit, my heart rate will be monitored using a Polar Electra heart rate monitor.
For safety purposes, during performance of these items if I experience intolerable discomfort, pain in the chest, shortness of breath, nausea, or dizziness, then I will immediately inform the testers and terminate the task without prejudice. Every effort will be made to conduct all the items in such amannerastominimize discomfort and risk. However, I understand that just as with other types of physical testing, there are potential risks. These potential risks include episodes of transient lightheadedness, fainting, chest discomfort, leg cramps, nausea, and extremely rarely, heart attacks.
I acknowledge that the testing procedures have been fully explained to me and that I can withdraw my participation at any time without any explanation. I acknowledge that I have read, understood, and completed the Health Appraisal Questionnaire, and discussed all negative responses with the Testing Co-ordinator. I also acknowledge that I have successfully completed a complete medical examination within the last 12 months if I am over the age of 40 years.
I hereby release the Ergonomics Research Group of Queen’s University and employees from any liability with respect to any damage or injury that I may suffer during the administration of any of these items as outlined above, except where the damage or injury is caused by the negligence of the Ergonomics Research Croup of Queen’s University and/or employees acting within the scope of their duties.
Signature Date
Witness Date
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APPENDIX D (CONT’D): INFORMED CONSENT FOR LABORATORY TESTS
I, author& the Ergonomics Research Group of Queen’s University, to administer and conduct laboratory tests designed to measure my aerobic capacity and muscular strength.
During the performance of the aerobic capacity test, my heart rate will be monitored using a Polar Electra heart rate monitor. If1 am 40 years of age or older, my heart rate will be monitored by a 3 lead EKG. For safety purposes, during performance of the laboratory tests, if1 experience intolerable discomfort, pain in the chest, shortness of breath, nausea, or dizziness, then I will immediately inform the testers and terminate the task without prejudice. Instructions in regard to the conduct of each test will be provided prior to the start of that test.
For the aerobic capacity test, I will be required to run at a constant pace of 5.0 mph. After 3 minutes of running at an initial grade of 0%, the grade of the treadmill will be increased by 1.0% every minute, until I can no longer maintain the pace.
For the strength tests, I will be required to do a maximal lift in the bench press, leg press, and latissimus pulldown.
Every effort will be made to conduct all the items in such a manner as to minimize discomfort and risk. However, I understand that just as with other types of physical testing, there are potential risks. These potential risks include episodes of transient lightheadedness, fainting, chest discomfort, leg cramps, nausea, and extremely rarely, heart attacks
I acknowledge that the testing procedures have been fully explained to me and that I can withdraw my participation at any time without any explanation. I acknowledge that I have successfully completed a complete medical examination within the previous six months if I am over the age of 40 years.
I hereby release the Ergonomics Research Group of Queen’s University and employees from any liability with respect to any damage or injury that I may suffer during the administration of any of these laboratory tests as outlined above, except where the damage or injury is caused by the negligence of the Ergonomics Research Group of Queen’s University and/or employees acting within the scope of their duties.
Signature
Witness
117
Date
Date
APPENDIX D (CONT’D): INFORMED CONSENT FOR FIELD TESTS
,
5 authorize the Ergonomics Research Group of Queen’s University, to administer and conduct a battery of field tests. This battery of field tests is designed to evaluate the major components of physical fitness. This battery of field tests consists of pre-screening, resting heart rate and resting blood pressure measurement, girth measurements, &infold measurements, a sub-maximal step test, a 1.5 mile run, sit-ups, push-ups, chin-ups, handgrip, a flexibility test, a balance tests, and a victim carry task.
For safety purposes, during performance of the laboratory tests, if I experience intolerable disco~ort, pain in the chest, shortness of breath, nausea, or dizziness, then I will immediately inform the testers and terminate the task without prejudice. Instructions in regard to the conduct of each test component will be given prior to the start of that test component.
Every effort will be made to conduct all the items in such a manner as to minimize discomfort and risk. However, I understand that just as with other types of physical testing, there are potential risks. These potential risks include episodes of transient lightheadedness, fainting, chest discomfort, leg cramps, nausea, and extremely rarely, heart attacks.
I acknowledge that the testing procedures have been fully explained to me and that I can withdraw my participation at any time without any explanation. I acknowledge that I have read, understood, and completed the Health Appraisal Questionnaire (EXERES), and the answers to all the questions were negative. I acknowledge that I have successfUlly completed a complete medical examination within the previous six.months if I am over the age of 40 years. I understand that all data will be grouped for the purposes of analysis and interpretation, and that my individual anonymity will be protected.
I hereby release the Ergonomics Research Group of Queen’s University and employees Corn any liability with respect to any damage or injury that I may suffer during the administration of any of this battery of field tests as outlined above, except where the damage or injury is caused by the negligence of the Ergonomics Research Group of Queen’s University and/or employees acting within the scope of their duties.
Signature Date
Witness Date
118
. APPENDIX E: HEALTH APPRAISAL QUESTIONNAIRE
This questionnaire is a screening device to identity those members for whom physical activity might be inappropriate at the present time. Please make a check mark beside either the “Yes” or “No” response as it applies to you. Should you have any questions, please do not hesitate to ask one of the testers.
To the best of your knowledge:
1. Do you have a restricted medical category which may prevent you from being evaluated on the step test or the circuit?
YES NO 2. Do you have arthritis or any other recurring problem with your back, shoulders, hips, knees, ankles, chest or pelvis which may present you from being evaluated on the step test or the circuit?
‘3. YES NO
Do you suffer from things such as: asthma, bronchitis, emphysema or other problems with your lungs?
YES NO 4. In addition to the above, is there anything which you feel should be discussed with a medical officer prior to assessnent?
YES NO 5. Are you taking any medication (prescribed or otherwise) which may affect your ability to undertake a physical evaluation?
YES NO 6. Have you ever been told by a doctor that you have high blood pressure?
YES NO 7. Have you ever been told by a doctor that you have a high blood cholesterol level?
YES NO 8. Do you have diabetes or other problems with your blood sugar levels?
YES NO 9. Do you smoke?
YES NO 10. Has anyone in you family, a parent or sibling, had a heart attack or other serious heart problems prior to age SS?
YES NO
Name:
Signature:
Date:
119
