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Author: Alaydaa, Thamer, Ali.
Title: Musculoskeletal Disorders in Electronic Frame Manufacturing.
The accompanying research report is submitted to the University of Wisconsin-Stout, Graduate School
in pmtial completion of the requirements for the
Graduate Degree/ Major: MS Risk Control
Research Adviser: Dr. Brian Finder
Submission TermN ear: Fall,2012
Number of Pages: 75
Style Manual Used: American Psychological Association, 6th edition
IZJ I understand that this research report must be officially approved by the Graduate School and that an electronic copy of the approved version will be made available through the University Library website IZJ I attest that the research report is my original work (that any copyrightable materials have been used with the permission of the original authors), and as such, it is automatically protected by the laws, rules, and regulations of the U.S. Copyright Office.
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This section forMS Plan A Thesis or EdS Thesis/Field Project papers only
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This section to be completed by the Graduate School This final research report has been approved by the Graduate School.
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Abstract
As result of significant increases in the occurrence of upper extremity work-related
musculoskeletal disorders (UEWMSDs ), Company XYZ has experienced sizable monetary
losses which are draining from the organization's profitability. The fact that UEWMSDs appear
over time has placed Company XYZ at continued risk of loss due to personal injuries, product
damage, legal expenses, and time lost. Therefore, the purpose of this study was to analyze and
identify the ergonomic risk factors that are causing upper extremity musculoskeletal
injuries/illnesses among photo-etch operators at Company XYZ. The focus of this study was to
perform a comprehensive review of Company XYZ's OSHA 300 forms, determine the
recommended weight limit for materials using the NIOSH Lifting Equation, and analyze the
workstation using the Rapid Upper Limb Assessment (RULA), as well as an ergonomic task
analysis worksheet. The results of the data collection used in this study indicate that there are
various risks present when workers perform the photo tool inspection at Company XYZ. Based
on the conclusions of this study, various recommendations were provided which may eliminate
or at least reduce the exposure of ergonomic-based risk factors and the occurrence of
musculoskeletal disorders for employees who are performing the photo tool inspection process at
Company XYZ.
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Acknowledgments
First of all I would like to thank Allah Almighty for giving me the courage and strength
to accomplish the success of completing my Master degree. Second, I would like to thank my
parents, brothers, and sisters for their courage and support over the past three years of my
graduate studies. Also, I would like to thank my wonderful wife and kids for their understanding
and supp01i that they have provided to me during my studies. I would also like to thank my
friends, colleagues, and the company where I did my research for their assistance and support.
Finally, a special thanks to my advisor Dr. Brian Finder for his patience, understanding,
expertise, and guidance from my first day into Risk Control Program to the completion of my
thesis.
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Table of Contents
.................................................................................................................................................... Page
Abstract ........................................................................................................................................... 2
List of Tables ................................................................................................................................. 7
List of Figures ................................................................................................................................ 8
Chapter I: Introduction .................................................................................................................... 9
Purpose ofthe Study ................................................................................................................. 11
Goals of the Study ..................................................................................................................... 11
Background and Significance ................................................................................................... 11
Limitations ................................................................................................................................ 12
Assumptions .............................................................................................................................. 12
Chapter II: Literature Review ....................................................................................................... 13
Background of Ergonomics ...................................................................................................... 13
Types of Musculoskeletal Disorders ......................................................................................... 14
Tendinitis .............................................................................................................................. 14
Tenosynovitis ........................................................................................................................ 14
Lateral epicondylitis .............................................................................................................. 15
Medial epicondylitis .............................................................................................................. 16
Carpal tunnel syndrome ........................................................................................................ 16
Thoracic outlet syndrome ...................................................................................................... 16
Vibration syndrome .............................................................................................................. 17
Causes of Musculoskeletal Disorders ....................................................................................... 18
Postures ................................................................................................................................. 18
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Repetition .............................................................................................................................. 19
Force ..................................................................................................................................... 19
Extreme temperatures ........................................................................................................... 21
Duration ................................................................................................................................ 22
Costs of Musculoskeletal Disorders ......................................................................................... 22
OSHA: Ergonomics Safety and Health Management.. ............................................................. 23
Ergonomic Risk Assessment Tools .......................................................................................... 24
Quantitative assessment ........................................................................................................ 24
Semi-quantitative assessment ............................................................................................... 25
RULA ................................................................................................................................ 26
NIOSH revised lifting equation ............................................................................................ 29
Ergonomics task analysis worksheet. ................................................................................... 33
Control Methods ....................................................................................................................... 34
Elimination and substitution ................................................................................................. 35
Engineering controls ............................................................................................................. 35
Administrative controls ......................................................................................................... 36
Personal protective equipment .............................................................................................. 3 7
Summary ................................................................................................................................... 38
Chapter III: Methodology ............................................................................................................. 40
Subject Selection and Description ............................................................................................ 40
Instrumentation ......................................................................................................................... 40
Data Collection Procedures ...................................................................................................... 41
Ergonomics task analysis worksheet. ................................................................................... 41
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Rapid upper limb assessment (RULA) ................................................................................. 41
NIOSH revised lifting equation ............................................................................................ 42
Data Analysis ............................................................................................................................ 42
Chapter IV: Results ....................................................................................................................... 44
Presentation of Collected Data ................................................................................................. 44
Objective one ........................................................................................................................ 44
Objective two ........................................................................................................................ 49
Objective three ...................................................................................................................... 51
Objective four ....................................................................................................................... 52
Discussion ................................................................................................................................. 54
Chapter V: Conclusions and Recommendations ........................................................................... 58
Major Findings .......................................................................................................................... 58
Conclusions ............................................................................................................................... 59
Recommendations ..................................................................................................................... 60
Elimination and substitution: ................................................................................................ 60
Engineering controls: ............................................................................................................ 61
Administrative controls: ........................................................................................................ 61
Areas of Further Research ........................................................................................................ 62
References ..................................................................................................................................... 63
Appendix A: Ergonomics Task Analysis Worksheet ................................................................... 68
Appendix B: RULA Employee Assessment Worksheet.. ............................................................. 75
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List of Tables
Table 2.1: Action score of RULA ........................................................................ 28
Table 2.2: Frequency multiplier ........................................................................... 33
Table 2.3: Coupling multiplier ............................................................................. 33
Table 4.1: NIOSH lifting equation ......................................................................... 49
Table 4.2: RULA scoring table ............................................................................ 51
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List of Figures
Figure 2.1: The extensor carpi radialis brevis ........................................................... 15
Figure 2.2: Thoracic outlet syndrome .................................................................... 17
Figure2.3: Repetitive task ................................................................................. 19
Figure 2.4: Activities that require force .................................................................. 21
Figure 2.5: 360 degree clear plastic goniometer ........................................................ 25
Figure 2.6: RULA employee assessment worksheet ................................................... 28
Figure 2.7: Graphic representation of angle of asymmetry (A) ....................................... 31
Figure 2.8: Hierarchy control .............................................................................. 34
Figure 2.9: Examples of engineering risk control ....................................................... 36
Figure 4.1: Incident cost obtained from Company XYZ' s injury records ........................... 45
Figure 4.2: Ergonomic risk factor cost analysis ......................................................... 46
Figure 4.3: Frequency of ergonomic risk factor cases obtained from Company XYZ's OSHA 300
log .............................................................................................. 47
Figure 4.4: Frequency of ergonomic and non-ergonomic injury analysis ........................... 49
Figure 4.5: Ergonomic Task Analysis Worksheet Summary .......................................... 53
Chapter 1: Introduction
It appears that various consumer-oriented business/industrial entities will often market
their products in different sizes in order to fit the people who purchase such for their personal
and/or professional needs. As an example, the clothing industry will typically offer different
sizes of garments in order to account for the wide variety of heights and girths of people who
may want to wear such items. This variation in product design can also be observed in
automobile seating systems that can be adjusted for height and other bodily dimensions of those
who may occupy the interior of the vehicle. As a result of the dimension-based differences that
appear to occur within a given population of individuals, manufacturers seem to be producing
products and equipment to meet people's requirements and ensure their comfort as well as
safety. Therefore, manufacturers have to understand the human body applications in order to
design these tools. These applications can be performed through a science that also focuses on
aligning work environment and workers to accomplish the best relationship possible (Tayyari &
Smith, 1997). This science of matching the worker with the work environment is called
ergonomics.
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The primary intention of ergonomics is to provide ample comfort, prevention of illness
and injury risks, improved productivity, and increased satisfaction along with the workers.
Jeffress (OSHA Archive, 2000) states that work-related ergonomic injuries cost employers a $15
to $18 billion of worker compensation in work environments every year due to the occurrence of
musculoskeletal disorders, soft-tissue injuries, and upper extremity as well as lower back
injuries. These types of injuries can be debilitating, serious, costly, but most importantly they
are preventable and an effective ergonomic program may not require significant amount of
money. It is often quite likely that risk managers are charged with implementing injury
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prevention programs witch focus on utilizing ergonomic techniques to align job-related demands
with employees' capabilities.
Company XYZ is a global technology leader that engages in the design, manufacture,
development, and supply of suspension assemblies for hard disk drives. Company XYZ
produces photo tools which consist of large plates of glass that contain images of parts. A
significant quantity of photo tools may require only a single piece of glass while others utilize
two pieces of glass that are hinged together. The photo tool is used in the manufacturing to
expose a part image on a thin sheet of metal. Due to the quality of the parts being produced, the
photo tools need to high quality images and therefore not contain defects. The photo-etch
operators at Company XYZ are required to examine the photo tools and remove unwanted
deficiencies or repair the areas that are missing parts of the image. This process requires a strong
level of awareness to repair the flaws. As a result of deficiencies in the design in their
workstations as well as long work hours in the photo-etch work area, workers have suffered
injuries/illnesses that are related to the touchup tasks that they are required to perform. Company
XYZ mangers' have experienced complaints from workers with regard to the presence
musculoskeletal disorders and have also incuned financial loss as a result of such physical
conditions requiring medical treatment from a local health care provider. Thus, the potential
presence of excessive force, duration, posture, and repetitious work activities among aging
photo-etch operators at Company XYZ is placing the organization at risk of incuning additional
upper extremity-based injuries/illnesses and related financial loss.
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Purpose of the Study
The purpose of this study was to analyze and identify the ergonomic risk factors that are
causing upper extremity musculoskeletal injuries/illnesses among photo-etch operators at
Company XYZ.
Goals of the Study
The goals of this study were to:
•!• Determine the frequency of ergonomic-based injuries/illnesses through a comprehensive
review of Company XYZ's OSHA 300 forms.
•!• Determine the recommended weight limit for materials and equipment that the photo
etches workers manually handles through the use of the NIOSH Lifting Equation.
•!• Perform comprehensive workstation analysis using the Rapid Upper Limb Assessment
(RULA).
•!• Perform comprehensive workstation analysis using an ergonomic task analysis
worksheet.
Background and Significance
As result of significant increases in the occurrence of upper extremity work-related
musculoskeletal disorders (UEWMSDs ), Company XYZ has experienced sizable monetary
losses which are draining from the organization's profitability. The fact that UEWMSDs appear
over time has placed Company XYZ at risk of losses for personal injuries, product damage, legal
expenses, and time lost. While the above-stated losses are considered to be direct costs, the
indirect costs may include training and replacement, decrease productivity, lost reputation,
administrative follow up, incident investigation, and increased insurance premiums. The total
number of ergonomic-based incidents which occmTed from 2003 to 2011 represents 53% of all
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the organization's employee-related losses. After experiencing a general decline in the costs
associated with ergonomic injuries after 2006, the loss-based costs once again begin to increase
after 2009. It should be noted that the occurrence of these injuries appear to be related with the
company's overall component production rate, but there are other factors that may be related to
the increase of injury costs like the state's worker compensation laws and medical treatment
costs. Therefore, the administration of Company XYZ is encouraging early diagnosis and
control as well as ergonomic design-based follow up in order to control these risk factors that can
impact the organization's profitability.
Limitations
1. This study was limited to the time period between September 1, 2012 to October 1, 2012.
Assumptions
1. It is assumed that the loss-based data which was received from Company XYZ was
correct.
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Chapter II: Literature Review
The goal of this research was to analyze and define the ergonomics hazard that cause
upper extremity musculoskeletal injuries/illnesses. This chapter provides information about
various ergonomic risk factors and injures that may be associated with it. Also, a description is
provided on the ergonomic assessment tools that can assist an ergonomist to analyze these
activities and the proper control-based techniques that may used to eliminate/reduce the hazard.
After that, an overview of the ergonomic costs that employers may incur annually with regard to
the occurrence of workplace design-based injuries will be provided.
Background of Ergonomics
In the twentieth century, ergonomics appeared as a result of concerted efforts by various
companies' efforts to correct system design and operational problems. It is a combination of
various sciences that have been used by scientists when they joined together to address difficult
issues and include the areas of anatomy, psychology, physiology, physics (mechanics and
environmental), and engineering (Bridger, 2009). Ergonomics looks at the use of information
about human action, limitations, and capabilities in the design of tools, machines, tasks, or
workstations in order to provide health, safe, productive, and effective individual use as well as
physical and mental comfort (Mustafa, Kamaruddin, Othman, & Mokhtar, 2009). Thus,
ergonomics is defined as the field of science that is concerned with achieving the best links
between employees and their working environment. The term ergonomics was derived from two
Greek words, ergon meaning "work" and nomikos meaning "law" (Tayyari, & Smith, 1997).
The ergonomist, or ergonomics practitioner, is focused on ensuring that the task/job is properly
adapted to individuals by indentifying the work stresses that may affect the workers' safety,
health, and efficiency. Therefore, the successful integration of ergonomics into the workplace
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system design process can enhance overall productivity by avoiding unwanted process
deficiencies which result in fatigue, inefficiency, accidents/injuries, user difficulties, errors, and
low morale (Bridger, 2009).
Types of Musculoskeletal Disorders
Chronic injuries of the musculoskeletal tissue or system are identified as cumulative
trauma disorders (CTDs) that affect the soft tissues of the body and may refer to a high rate of
manual repetition tasks (Putz-Anderson, 1988). Cumulative trauma disorders (CTDs) may be
referred to as regional musculoskeletal disorders, repetitive strain/musculoskeletal injuries, or
overuse syndrome (Putz-Anderson, 1988). According to Putz-Anderson (1988), various types
of cumulative trauma disorders include tendinitis, tenosynovitis, ganglionic cyst, lateral
epicondylitis, medial epicondylitis, carpal tunnel syndrome, thoracic outlet syndrome, and
vibration syndrome.
Tendinitis. Tendinitis is the inflammation or swelling in the tendon which attaches the
muscle to the bone and is often caused from the stresses of repetitive strain (Putz-Anderson,
1988). As a result of extra effort on the worker's part, fibers that form the tendon can tear away
from each other. Also there are certain, tendons, like those which are located in the shoulder,
that are not sheathed and can become calcified as result of injury (Putz-Anderson, 1988).
Tenosynovitis. Tenosynovitis is inflammation of the synovial sheath that surrounds a
tendon. As a result of extreme repetition, the sheath produces an extreme quantity of synovial
fluid (Putz-Anderson, 1988). This fluid becomes swollen, painful, and the joint becomes
difficult to move where the inflammation occurs. For instance, repetitions that exceed 1500 to
2000 per hour can lead to tendon sheath irritation. In some situations, the tendon can become
locked in the sheath and any movement will cause snapping movement. This condition is often
15
called trigger fi nger, trigger thumb, or stenosing tenovaginitis. Furthermore, De Quervain's
syndrome is the most familiar stenosing tenovaginitis (Abrisham, Karbasi, Zare, & Behnamfar,
20 11 ). De Quervain's syndrome affects the tendons of the lower part of the thumb and the side
of the wrist. This disease is result from the excessive friction of the thumb tendons and their
sheath that resulted from the activities that require heavy use of the thumb (Putz-J\nderson,
1988).
Lateral epicondylitis. Lateral epicondylitis is an inflammation of the tendons that
anchor to the muscles of the forearm. It often takes place at the extensor carpi radialis muscle
(Figure 2. 1) (Chaudhary, Rathore, Han if, & Rashid, 20 II ). Lateral epicondyli tis is also known
as tennis elbow because it more commonly occurs with individuals who play this sport. rt should
be noted that any activities or sports which use the ann for gripping or throwing can cause this
issue (Putz-Anderson, 1988). Symptoms that are associated with this physical ailment may
include pain at the lateral epicondyle on the outer side of the elbow and may increase with
activity that is required for the extension/holding with the wrist or arm.
Figure 2.1: The extensor carpi radialis brevis (American Society for Surgery of the Hand, 2006).
16
Medial epicondylitis. Medial epicondylitis is inflammation in the tendon that is
connected to the finger flexor muscle inside of the elbow. Medial epicondylitis may be caused
by activities that require more powerful rotation ofthe forearm and flexing of the wrist (Putz
Anderson, 1988). Also, medial epicondylitis is known as golfer's elbow because it can affect
athletes. Symptoms of this disorder may include pain at the medial epicondyle and may increase
with activities that require the use of the flexor muscles in a bending motion (Wolf, Mountcastle,
Burks, Sturdivant, & Owens, 2010).
Carpal tunnel syndrome. The carpal tunnel is a small diameter area which contains
nerves and tendons within the palm side of the wrist. Subhan et al., (2012) postulate that when
the carpal tunnel size is reduced or the volume of its content is increased within any condition,
the median nerve maybe compressed. For example, a worker supports his arm by leaning the
forearm against a sharp edge. As a result, the mechanical disruption of the nerve function may
occur as well as cause ischemia. Ischemia is insufficient blood flow to the body area because of
blockage blood vessels to supply that area. In time, symptoms appear as pain, numbness, and
tingling ofthe hands (Subhan et al., 2012).
Thoracic outlet syndrome. Thoracic outlet syndrome is the symptom resulting from
pressure or irritation of neural structures or arteries which exit the rib cage through a narrow port
(Lindgren, 201 0). Some other terms used for thoracic outlet syndrome include neurovascular
compression syndrome, hyperabduction syndrome, and cervicobrachial disorder (Putz-Anderson,
1988). In fact, the thoracic outlet consists of the first rib and Sibson's fascia and contains many
structures in a confined space. Lindgren, 2010 argued that the compression ofthe neurovascular
may frequently take place at three different levels. These three levels are in the superior thoracic
outlet, in the costoscalene hiatus, or in the costoclavicular passage (Lindgren, 201 0). The
17
superior thoracic outlet is bounded anteriorly by the manubrium, posteriorly by the spine, and
laterally by the fi rst rib. The costoscalene hiatus is bounded posteriorly by the middle scalene
muscle, anteriorly by the anterior scalene muscle, and caudally by the first rib. The
costoclavicular passage is bounded posteriorly by the scapula, laterally by the clavicle, and
medially by the first rib (Lindgren, 20 I 0). The work-related thoracic outlet syndrome may occur
when the worker is frequently required to reach above shoulder level (Figure 2.2).
· '-'~.......... .....,. c..
Notm~lanatorny Thoracic Outlet Syndrome Tho ihtO<OCIC OUIItl l yndiOII\0 II o group of aymploma o~11ng 001 0111y It om lho upl)tr oxllomltr. bul nl110 from 11>o chu t. noek. lind ahoulc!Q ThO aymplomt nro prcducod by n PQtlliOt\31, lnlorm.ttenl comprenton of lho bt!Kh .. l plexus ondi<W avbcllovlan o"ery ond voln
-robdu<UOn oyndmM ------_.,.. __ .. _
Figure 2.2: Thoracic outlet syndrome (source: Beyond Wellness LLC, 2011)
Vibration syndrome. Vibration syndrome, also known as Raynaud's phenomenon or
white finger, is a century old disease that is generated by prolonged usc of vibrating hand-held
equipment such as chain saws, pneumatic hammers, and power grinders (Putz-Anderson, 1988;
Mitu, Leon, & Florescu, 20 11 ). Research confirms that vibration tools can also contribute to
occtmence of carpal tunnel syndrome (SaLmi et al., 2009). Therefore, the risk factors that arc
associated with vibration syndrome are the vibration dose and time exposure. Tt should be noted
that vibration syndrome is more common in men than women (Mitu, Leon, & Florescu, 20 11 ).
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Thus, the proper way for eliminating exposure to vibration is by controlling the etiologic factors
and modifying the workplace. These factors can help to determine the disease symptoms that
may depend on the body factors such as age and/or the existence of musculoskeletal disorders,
harmful environmental factors such as exposure to a cold microclimate and noise, or any specific
work-related conditions such as the weight and shape ofthe tool (Mitu, Leon, & Florescu, 2011).
Causes of Musculoskeletal Disorders
Musculoskeletal disorders (MSD's) have been recognized as a major cause of ill-health
or disability in a number of workers in the last few decades and therefore have become one of the
important issues that ergonomists face at work around the world (Hossein, Reza, & Abolfazl,
2011). As a result, both time away from work and difficulties encountered in the workplace such
as loss of work productivity as either quantity or quality as result of workers injuries/illnesses are
forms ofwork disabilities caused by MSD's (Roy et al., 2011). The risk factors that are
associated with musculoskeletal disorders (MSD's) include workplace activities such as
awkward postures, rate of manual repetition tasks, excessive manual force, extreme temperature,
and work duration (Bridger, 2009).
Postures. Certain jobs may require the worker to use awkward postures that pose
significant risk to the joints and soft tissues which are active during physical activity. Positions
that are typically associated with awkward postures may include kneeling, twisting, and extended
reaching, even though if these positions performed for a short period oftime (Choobineh,
Tabatabaei, Tozihian, & Ghadami, 2007). Therefore, these awkward postures may involve some
areas ofthe body such as neck, wrist, shoulder, arm, knees, hand, and back. Furthermore, the
reasons behind the occurrence of awkward postures may include poorly designed
tools/equipments, workstations, or a lack of proper training on how to use equipment correctly
(Agrawal, Madankar, & Jibhakate, 2011). Awkward postures are also found to be linked to
reduced effectiveness and performance of workers (Choobineh, Tabatabaei, Tozihian, &
Ghadami, 2007).
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Repetition. Body motion can be dangerous when it involves continues use of certain
joints and/or muscles. Workers who are performing highly repetitive actions are at the highest
risk for MSD's (Anderson, 1988). Although ergonomic-based conditions have been improved in
many industries, many workplaces still need workers to carry out repetitive tasks (Spallek, Kuhn,
Uibel, Van Mark, & Quarcoo, 2010). When task requires high rate of repetition, such as fast
paced palletizing activities as displayed in Figure 2.3, the ergonomist must take in his/her
consideration the posture of limbs, force demanded, and the predictable recovery period when
he/she redesign the process. For instance, repetitions should not exceed 1500 to 2000 per hour to
prevent the symptoms of tendon sheath irritation (Putz-Anderson, 1988).
Repeatedly lifting heavy boxes stresses the same body parts again and again.
Figure2.3: Repetitive task (California Department of Industrial Relations, 1999)
Force. Force is the amount of muscular output that is required to perform various
activities such as lifting, lowering, carrying, holding, pushing, or pulling. It is a critical factor
that contributes to start musculoskeletal disorders. Excessive levels of muscular effort can
20
decrease the circulation to the muscle and result in fatigue (Anderson, 1988). There are two
types of muscular effort, which include dynamic and static oriented motions. Dynamic effort is
rhythmic rotation of tension and relaxation, or muscular extension and contraction. On the other
hand, static effort is a state of muscles contraction for a long period of time (Grand jean, 198 8).
The basic difference between dynamic and static muscular effort is that the muscle works to help
pump the blood during dynamic effort. However, in static effort situations, the blood is unable
to flow through the muscle since the internal pressure of the muscle compresses the blood
vessels (Chengalur, Rodgers, & Bernard, 2004). The key point between dynamic and static
effort is the amount of movement that linked with the muscle contractions. Static effort is more
difficult than dynamic because of the potential for muscle fatigue. Therefore, static effort can be
considerable when high non-movement muscular effort is sustained for 10 seconds or more,
moderate effort continues for 1 minute, or minor effort ( about 1/3 of maximum force) take place
for 4 minutes or more (Grandjean, 1988). In fact, the time required for muscular-based recovery
can exceed the actual work time when high forces are demanded and little/no movement exists
during the performed task (see Figure 2.4).
21
Push Pull Carry
Figure 2.4: Activities that require force (source: Worl\.SafeBC, pull, push, & carry
calculator 2012).
Extreme temperatures. Working in an extreme temperature environment can be
dangerous to workers. Excessi vc heat exposure is known as heat stress and work in such
environment places a significant demand on the cardiovascular system. Both skin and working
muscle require an increase in blood tlow, where the skin requires up to I 0 L/min and the
working muscle up to 25 Llmin (Bridger, 2009). Since the average maximum cardiac output is
about 25 Llmin, the demands cannot increase blood flow by converting blood from the viscera to
supply the working muscles and cooling the body (Bridger, 2009). When the body temperature
exceeds 42°C the blood pressure decreases and the vital organs such as brain, heart, and kidney
do not have enough blood flow. Some of the conditions that may occur as the core temperature
increases are heat exhaustion, heat hyperpyrexia (heat stroke), heat hyperventilation, or heat
syncope. On the other end of the spectrum, the excessive cold exposure is known as cold stress
(Bridger, 2009). The body temperature can be controlled if the worker is provided with
protective clothing in the cold. When the worker performs physical activities, the metabolic heat
amount increases three times when it is compared to non-performing activities. Therefore, it is
22
recommended to maintain the workers' physical activities in cold environments and thus
maintain the metabolic heat generation that will maintain a reasonable level of body warmth.
The central nervous system can be disrupted when the core temperature becomes less than 33°C.
When workers are exposed to cold stress, the negative bodily responses may include thickening
of synovial fluid, decreases muscle output and reduced blood flow from vessel constriction. The
condition that may occur as the core temperature decreases is referred to called hypothermia
(Bridger, 2009).
Duration. This risk factor refers to the hours of work (during a given shift) that workers
must incur and can vary in length between 8 to 12 hours. Over the past 100 years, many
countries have used the 8 hour per day and 5 day work week approach (Bridger, 2009). There is
a study that was conducted for the German working population to analyze incident risk and its
relationship to working hours. After analyzing data which was located within the Swedish
Occupational Injury Information System, it was found that the accident risk was almost at the
same level during the first 8 to 9 hours (Hanecke, Tiedemann, Nachreiner, & Grzech-Sukalo,
1998). However, it was found that the incident risk exponentially increased after the 9th hour of
work, although these findings need to be supported by more research to identify the fundamental
causes of the accidents. Although, the 8 hour shift is widely established, the United States has
the tendency to increase the job time beyond this time frame (Hanecke, Tiedemann, Nachreiner,
& Grzech-Sukalo, 1998). It should be noted that working a 12 hours shift may be popular
among the workers because of the extended period of time-off that is provided to the employees.
Costs of Musculoskeletal Disorders
Since production-based work must be performed by a certain number of employees,
employee absenteeism is a significant factor that may reduce an organization's productivity.
23
Musculoskeletal disorders cause injuries at the workplace and thus result in worker
compensation costs to cover the medical loses which are associated with these incidents (Office
of Ergonomics Research Committee, 1996). The rate of non-fatal workplace injury and illness
cases that required days off work in order for the employee to recover was 118 per 10,000 full
time workers in 2010 (US Bureau oflabor statistics, 2011). During this same year, the rate of
musculoskeletal disorder (MSD) cases that required days away from work increased 4% from
2009 to 34 cases per 10,000 full-time workers for all employers (private industry, local
government, and state government). In regards to the type ofMSD's that most often occurred,
back and shoulder disorders were almost the half of all occupations. In light of the fact that
approximately 346,400 MSD's occurred in 2010, this means that 29 percent of all workplace
injuries and illnesses required days away from work in 2010 were related to some type of a
workplace design issue (US Bureau of labor statistics, 2011).
OSHA: Ergonomics Safety and Health Management
On Feb. 2, 1996 OSHA proposed a revised version ofthe recordkeeping requirements for
occupational injuries and illnesses (OSHA form 300) to raise the accuracy of collecting data
(Roughton, 1997). This revised version provided better use of injuries/illnesses records,
enhanced employee participation and awareness, and improved the information system of
injuries/illnesses. The OSHA form 300 is a record of information where employers must report
work-related deaths, injuries/illnesses, medical treatment beyond first aid, days away from work,
or job restricted/transferred and this must be document to the OSHA annually (OSHA, 29 CFR
1904). The OSHA form 300 must be used wisely to protect the confidentiality of employees
since it contains information that relate to the employees' health. While some employees may
not view it in such a manner, this recordable injury/illness information may be used as a tool for
24
a company's management to review existing loss-based data (Roughton, 1997). By reviewing
the records, it allows the management to evaluate and develop the company's safety and health
standards, identify and evaluate the workplace hazards, and carry out risk assessment with regard
to injury/illness causes and prevention methodologies (Roughton, 1997).
Ergonomic Risk Assessment Tools
There are numerous tools that can be used in the assessment of job/task analysis. Several
of these tools are based on equipment-generated measurements while others utilize more of a
visual inspection approach (Bridger, 2009). Chengalur, Rodgers, & Bernard (2004) have divided
assessment/technique methods into categories of quantitative and semi-quantitative, and
following is a summary of these approaches.
Quantitative assessment. Quantitative assessment places more effort on gathering data,
concentrating on high-risk body joints/limbs, considering a number of contributing factors, and
analyzing such data to make a decision (Chengalur, Rodgers, & Bernard, 2004). In fact, when
the severity of the risk is not clear, quantitative tools can be more practical. When conducting
the ergonomic quantitative assessment, recording tools to aid in the study are used. In processes
that include the measurement of bodily functions and response to various activities, video
cameras are used to provide a visual representation of the proceeding. In quantitative types of
research, results are recorded in numerical values that represent actual measurements which can
be replicated. It is in the best interest of a researcher to take numerous measurements as a
backup plan to verify his/her originally-collected data. Given that work-based measurements are
recorded for various body parts, the potential in which an individual at work may incur injuries is
estimated through a comparison between what the job requires and anthropometric data. These
procedures define the level of body balance in accordance to pressure which is exerted on
25
various body parts. It should be noted that the angular positioning of various body pmis
determines the ability of an employee or a worker to continue working from a given position
(Arthritis Foundation, 1985). The time required to perform a task can be increased and affected
by the body postures, inflexion angles of the limbs, connection between the neck and the body
trunk, and movement of the wrist.
These movements and bodily functions are measured in accordance to the processes
measuring tools and are presented or recorded on devices to help in quick and concise analysis of
results. One form of instrumentation which is used to collect data for ergonomic quantitative
assessment may include a goniometer (Briggs & Green, 1989). A goniometer is used to measure
a joint's range of motion (see Figure 2.5) and can be considered to be similar to a protractor. It is
an appropriate device used in the determination of a patient's level of movement or mobility due
to injury or else to quantify the postural demands of a particular task.
trlWH9$li!C I<Mt? fi¢f~~t.>
~UUJM!'i.m-Y<a
Figure 2.5: 360 degree clear plastic goniometer (Source: electro-medical, 2012)
Semi-quantitative assessment. Semi-quantitative assessment methods may require
additional effort with regard to gathering data, are able to concentrate on a body joint/limb, and
can consider a number of contributing ergonomic risk factors (Chengalur, Rodgers, & Bernard,
2004). Semi-quantitative assessment can be recommended either when professional judgment of
the risk factors for a task/job are known, or when qualitative assessment focuses on a body
region. One of the more common semi-quantitative tools may include the Rapid Upper Limb
Assessment (RULA) analysis which will be discussed in greater detail.
26
RULA. RULA was developed by Drs. Lynn McAtamney and E Nigel Corlettis in 1993.
It is a fast observational method for workplace inspection where ergonomic injuries are reported.
It is an appraisal chart which recording permits the process of activities of employees in
accordance to their active pmiicipation in a task. The required application of RULA has been
reported by employees and managers to assist with understanding musculoskeletal loading and
foster change in the overall workstation design. Changes which need to be made to the
workplace are associated with the grand scores that essentially reflect the risk for ergonomic
based injuries to occur (Hendrick, 1995). The RULA employee assessment worksheet is a
document that presents management with an assessment of the type of work that employees must
undertake in the work place. The usefulness of the RULA employee assessment worksheet is its
ability to identify moderate to high risk ergonomic-based and consequently influence
management to improve performance and production in general (Hendrick, 1995).
RULA is divided into three developmental phases that define and determine the
wellbeing of an individual in terms of their working postures/activities, the scale of action
system and an overall scoring system. Working postures are divided or a classified into specific
areas including the arm, wrist, neck, trunk, and the legs. This division helps in the application of
the scoring system, which classifies the activities of several body parts in accordance to their
application of angles. The working postures are defined by the bending of the truck, twisting of
the wrist, movement of the joints, and movement of the arms. Managers can apply the RULA to
27
determine the safest and the quickest way of aligning machinery with the physical limitations of
the employees (McAtamney, et, al. 1993).
Employees and managers can use the RULA scoring system as a risk management tool to
determine the employees' working postures and the effect of the work that they are subjected to.
In this case, an employee is likely to hmi him/herself if twisting of the spine occurs. The scoring
system classifies working postures in angles and limits some of the working postures for the arm
and the neck among other parts within a certain angular range (motion range).
• For arms, 60°- 1 00°angles are classified or marked with a value of 1, and a 2 if
they fall below 60° or exceeds beyond 100°.
• For the neck, 0°-10 ° is marked with a value of 1, 10°-20 ° with a 2, 20° +of
neck flexion with a 3, and 4 in cases of neck extension.
• For the cases of trunk, a 1 is added anytime if it is side bending or twisting.
• If the neck is twisting or side bending the value can be adjusted by adding a value
of 1.
The reason for adding a value of 1 in every twist or deviate-based motion is to account
for high-risk as well as strenuous activities (see Figure 2.6). The scale of action system is the
actual recording of an employee's activities with regard to his/her likelihood of incurring some
form of musculoskeletal injury. The scale of action can be categorized in the same class as the
RULA employee assessment worksheet and measures the effort involved with connecting
various work particulars and the ability of the employee to handle tasks continuously and in a
certain postures. The differentiation aspect of one employee to another is determined by the
scoring system, which represents the scale of action system (Table 2.1) (GAO, AEF A, and
Raytheon 1997).
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SCORES
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VIPtt :~ ~~ ~:: ~~ r~· . - -. 121212 1 2
I 2 2 2 2 I l I
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l l l l I •• l l I 4 4 •
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28
Figure 2.6: RULA employee assessment worksheet (Source: University of South Florida
College of Public Health, 2009)
Table 2.1: Action score of RULA (Source: Neeae Consulting, Inc, 2004)
SCORE DESCRIPTION
1-2 Posture is acceptable
3-4 Further investigation is needed and changes may be required
5-6 Investigation and changes are required soon
7 Investigation and changes are required immediately
29
NIOSH revised lifting equation. The NOISH lifting equation has been used widely by
safety and health practitioners since it was first developed in 1981. In 1991 the lifting equation
was revised to cover a greater percentage of lifting tasks (Waters, Putz-Anderson, Garg, & Fine,
1993). The NOISH lifting equation assists practitioners to evaluate lifting jobs/tasks that
increase the risk of causing musculoskeletal disorders by calculating the recommended weight
limit (RWL) for a giving task through the incorporation of a multiplicative model which provides
a weighting for each of six task variables. The weighting as described and presented by the
equation is meant to decrease the loading constant (LC) which represents a maximum weight 23
kg or 51 lb that a person should lift or lower. The equation is highlighted below, and its steps are
subsequently explained.
RWL=LC xHMx VMxDMxAMxFMx CM
The horizontal multiplier (HM) measures the horizontal location from the central part of
a line which connects the inner bone of the ankle to a spot which is directly below the central
point where the hands grasp the load (Hewlett Packard, 1992). This distance is expressed as HM
and the horizontal multiplier is therefore calculated as 1 0/H, when H is measured in inches and
25/H when H is measured in centimeters. The multiplier is 1.0 if, and only if, H is >= to 10
inches because HM decreases with an increase in horizontal distance. HM is reduced to 0.4
when the horizontal distance is 25 inches or 63 centimeters. If the horizontal distance is greater
than 25 inches, then zero is the value for HM (Waters, Putz-Anderson, Garg, & Fine, 1993).
The vertical multiplier (VM) defines the vertical height of the hands above the floor
which an individual is standing on. VM is measured vertically from the surface an individual is
standing on to the midpoint ofwhere the hand grasps (Hewlett Packard, 1992). A limit to the
floor and the maximum height of lifting are defined as the vertical restriction. Measurement of
30
the vertical location should be performed from the origin and destination of the lift to indicate
travel distance. In order to determine the vertical multiplier, an optimum height of 30 inches (75
em) is calculated from the absolute or deviation ofV. Therefore, the vertical multiplier (VM) is
(1-(0.0075[V-30])) where Vis measured in inches (Waters, Putz-Anderson, Garg, & Fine, 1993).
The distance between the origin and the destination of a lift is referred as Vertical Travel
Distance (D) (Hewlett Packard, 1992). The value ofD is assumed to be between 10 and 70
inches. If the ve1iical distance is smaller than 10 inches, then D should be adjusted to 10 inches.
The distance multiplier (DM) is calculated as (0.82+ (1.8/D)) and is measured in inches. The
calculated DM value decreases consistently with an overall increase in travel distance (Waters,
Putz-Anderson, Garg, & Fine, 1993).
A lift which begins and ends outside of the midsagittal plane as displayed in Figure 2. 7 is
known as asymmetry. In normal working conditions, asymmetrical lifting should be avoided,
but in cases where it must be performed, weights should be smaller than those which may be
lifted in symmetrical lifting (Hewlett Packard, 1992). However, if the origin and the destination
of the lift are elevated at an angle, an asymmetrical lift may be required. The asymmetric
multiplier (AM) is restricted to zero if the worker's overall angular rotation is greater than 13 5°.
The AM is calculated as (1-(0.0032A)), and has a maximum value of 1.0 ifthe load is
maintained directly in front of the midline. The AM decreases with a linear increase of the angle
of asymmetry (Waters, Putz-Anderson, Garg, & Fine, 1993).
31
Figure 2.7: Graphic representation of angle of asymmetry (A) (Source: Applications
manual for the revised NIOSH lifting equation).
The number of lifts per minute, the amount of time invested in the lifting activity, and the
vertical height of the lift above the floor are variables which are used to define the frequency
multiplier (FM). The average number of lifts that the worker performs per minute defines the
lifting frequency (see Table 2.2) (Hewlett Packard, 1992). For repetitive lifting, the frequency
range is from 0.2 lifts per minute to a maximum frequency depending on the vertical location of
an object and the amount of time which is required to perform in the lift. The FM value depends
on the mean of lifts per minute (F), vertical location (V), and the amount of time taken in
continuous lifting. For tasks which require a frequency ofless than 0.2 lifts per minute; the
frequency should be set to 0.2 lifts per minute (Waters, Putz-Anderson, Garg, & Fine, 1993).
32
The nature of the gripping mode may affect the maximum force that worker can or must
perform and the vertical location of the hands through the lift. Therefore, a good coupling may
reduce the maximum grasp forces that are required and increase the suitable weight for lifting,
while the poor coupling will increase the grasp forces and reduce the suitable weight for lifting.
In fact, a good coupling may become a poor coupling if a single hand lift is performed. The
coupling is classified as good, fair, and poor with regard to values of the vertical location being
less than 30 inches or else greater than or equal to 30 inches as display in Table 2.3 (Hewlett
Packard, 1992). If there is a doubt in classifying a particular coupling, it is recommended that
the respective analyst use the most stressful classification.
The lifting index (LI) is defined as the estimated level of physical stress that is associated
with a manual lifting task by using the weight of the load that lifted and the RWL (Waters, Putz
Anderson, Garg, & Fine, 1993). The LI can be calculated by dividing the load weight by the
RWL. When the LI magnitude increases, the risk level for a given worker to sustain a back
related disorder would also increase. The LI has been used to identify the potential risk that
associated with job; therefore, a lifting task with aLI value greater than 1 would increase the risk
for lifting-related low back pain. Thus, the goal is to design the lifting jobs to achieve aLI of
one or less (Waters, Putz-Anderson, Garg, & Fine, 1993 ).
Table 2.2: Frequency multiplier (Source: NIOSH, 1997)
h'ork Duration -------------------------------------------------
~'requency
:..,ifts/min (E'):
2 3
10 ll 12 13 14 15
>15
<'"'' Ho0.r -------------V<JO" V>~30
i.OO l. 00 . 97 . 97 .94 • 94 . 91 .9i • 88 .88 . 84 .81 .80 . 80 .'l':J .75 .70 . 7 0 . 60 . 60 .52 .52 .15 .45 .lfl .~:.
.37 .37
.00 .34
.00 • 31
.co .28
.co .00
t Values of V are in .inches
>1 but <~2 Hours >2 but <~8 Hours
---------------- ----------------V<30 V>c"3Q V<30 V>~30
.95 .95 .85 .85
.92 .92 . 8!. . 8l
. 88 .88 ."J'J . 7 5
.84 . 84 .65 .65
.79 . 79 .55 .ss
.7?. .7:! .I; 5 .45
. 60 .60 .JS .3:::
.50 .50 .n .n
.42 • 4 2 .22 .22
.35 .35 • l B .18
. 30 .30 .DC .lS
.26 • 26 .00 .13
.00 .23 .00 .DO
.00 .21 .00 .00
.00 .00 .00 .00
.00 .00 .oc .oc
.00 .00 .oa .oc
.00 .00 .oc .00
For lifting less frequently than once per 5 minutes, set F = 0.2 l~f~s/rninute.
Table 2.3: Coupling multiplier (Source: NIOSH, 1997)
Coupling multiplier Coupling type
V < 30 inches V > = 30 inches
Good 1.00 1.00
Fair 0.95 1.00
Poor 0.90 0.90
33
Ergonomics task analysis worksheet. Developed by Great American Insurance Group,
the ergonomics task analysis worksheet offers a method to evaluate, identify, and
control/eliminate the risk factors of ergonomic. These risk factors may include repetition,
posture, vibration, reach/proper height, force, static loading and fatigue, pressure/contact stress,
lifting and material handling, and environment. The scoring system for these risk factors differs
from either ideal (1, 2 ... 30), warning level (lA, 2A ... 30A), or take action (lB, 2B ... 30B). Each
risk factor must be scored in reference to the drawing which most resembles the task that's being
34
analyzed (see Appendix A). Any task that falls within the A orB "take action" columns should
be addressed to control the risk. The preferred practices that are addressed within this ergonomic
task analysis worksheet have been established by NIOSH and OSHA which makes this particular
tool practical method for identifying, quantifying, and addressing ha:t.ards in the workplace
(Great American Insurance Group, 2004).
Control Methods
Once one or more musculoskeletal disorders (MSD' s) risks have been identified and
evaluated, analysts need to create a suitable control strategy. The common control-oriented
strategies are called "hierarchy of controls" (see Figure 2.8) because of the options that can be
implemented to ensure the effective implementation of a workplace hazard control (NO ISH,
1997). The hierarchy of controls follows a ranking approach from most effective to the least
effective and includes elimination, substitution, engineering controls, administrative controls,
and personal protective equipment (NO ISH, 20 1 I ). In fact, elimination and substitution can be
considered as a patt of the engineering controls because of the design process.
Hierarchy of Control Apply the highest level cf ccnlrcl ccmmensur~lc with the risk level-lower value controls may be used In lhe Interim until
long·term controls are Implemented.
ELIMINATION SUBSTITUTION
ENGINEERING
I '"'"'·~""'"''' , ...
•rod~.,...
-- ~ :
Figure 2.8: Hierarchy control (Source: Machine Safety Specialists)
35
Elimination and substitution. Both elimination and substitution are considered the
most effective process to control musculoskeletal disorders (MSD's) risks. Ifthejob process is
still in the design phase, the implementation of elimination and substitution can be used easily to
apply the proper design and use an alternative substance that is less hazardous (NOISH, 2011).
These approaches tend to be diffi~ult to apply in the existing job process since significant
changes may be required to reduce the risk.
Engineering controls. Engineering controls are the ideal approach for the designer in
order to control and prevent musculoskeletal disorders (MSD's) where the physical characteristic
of the workplace may change with regard to work methods, selection and use of tools, and the
workstation layout (NOISH, 1997). The ideal connection helps to reduce the work-related risk
factors such as unacceptable postures and static loading of the body parts in order to make the
work less stressful. In fact, engineering controls are considered the most effective long term
approach that may reduce MSD's risk factors that associated with work (Chengalur, Rodgers, &
Bernard, 2004). For example, changing the workstation layout where materials/tools can be
located within the reaching distance or the height of workstation can be adjusted to enable the
worker to activate the control easily (NO ISH, 1997). Another example of the engineering
control is using mechanical assist devices to change the way that materials/products can be
transported to mitigate the heavy load carrying and lifting activities. Also, changing the
equipment design is another approach for engineering control, for example, using pistol handle
grips to reduce the wrist deviation. Figure 2.9 displays a number of options to control various
identified risk factors.
f"~1.l Raise and til tthc
~con taincr for easier ac.cc~s ancl Lo reduce bending and litting burdens.
~Usc a_LUmtabic ~ wnh hxturc to hold the work; sclc.:t a tool that reduces wrist deviations.
~Usc nK"Chanical ~assist devices for less stressful handling.
i T I b <end and '.·u. pport ' tool to red ucc stre!'s on arm and shoulder.
. ..
Round or pad cuges of guards, curllain
crs. or work tables.
Select power tools with anti-vibnuion
properties. Usc handle coatings that suppress vibrations: increase coefficient offriction to reduce f(>rcc requirements.
~ U!>c conveyors to X reduce twisting
and elintinatc lifting and carrying.
~Raise worker with ~ platfurnl and u,e in-line tool to '""ducc wrist bL"Tiding.
Usc balancers. '---:-----' isolators and
damping materials to rL-ducc vibrations at the so urcc or a lung transruis,ion path. 1\-1akc driving surface smooth.
Figure 2.9: Examples of engineering risk control (Source: NIOSH, 1997).
Administrative controls. The administrative controls are management-based policies
which are used to reduce or control the risk factors by training the workers how to perform the
job properly to reduce the stress and strain, rotating the workers during work, or changing the
work procedures (NOISH, 1997). Administrative controls can be performed when the
36
engineering controls are not technically possible. At this time, the management must be sure that
the policies and standards are being followed because the administrative controls do not prevent
the risk (NOISH, 1997). For example, to control the repetitive motion workers can be rotated
37
through different works. The employees need to share their work to avoid repeating the same
movement and that can be implemented in either weekly or daily schedules. Also, the work-rest
schedules can be modified to provide more rest breaks with sh01i duration (Bridger, 2009). At
this time, the worker can perform different activities that would help for recovery of muscles.
Moreover, workers must be trained on how to perform the work correctly to reduce the risk by
implementing the correct position and utilize the right tool (Tayyari & Smith, 1997).
On the other hand, it is the duty of an employee to take his duties seriously, adhere to the
organization's policies, and uphold the ethics of that organization (Tayyari & Smith, 1997).
Most importantly, employees are required to respect the objectives of the general organization
while at the same time committing to the standards. The work of managers is to create surplus
by planning, staffing, organizing and implementing policies that drive the performance towards
sustainable growth of the organization (Bridger, 2009).
Personal protective equipment. The Personal Protective Equipment (PPE) reduces the
hazard by blockade the source. Safety goggles, respirators, safety shoes, ear plugs, and hard hats
are examples ofPPE (NOISH, 1997). PPE is often used within processes that already existed
and hazard is not mostly well controlled. Also, PPE may not be expensive to set up; however,
over the time it can be expensive. In fact, there is consideration on the effectiveness of PPE from
ergonomics standpoint. Although PPE may reduce the hazard exposure, it may increase it again
because the worker may not be comfortable or has to fight the PPE in order to perform the work
(NOISH, 1997). PPE sometimes reduces the productivity by minimize the practical movement
that workers need during the work. For example, using vibration attenuation gloves to attenuate
vibration make it harder to worker to grip the tools. At this time, worker may apply more force
to control the tools which may cut the blood flow to the fingers and fatigue may increase
(Anderson, 1988).
Summary
38
This chapter highlighted the most significant risk factors which are associated with the
occurrence ofMSD's in workplace activities and the OSHA legislation. When conducting the
ergonomic quantitative assessment, recording tools are used to aid in the study. These tools
include audio recording in that an observer or the researcher can record measurement in audio
and video formats. The use of a video recorder is to account for time lapsing with recording of
events on a virtual memory or tape. Other measurement devices include; a goniometer which
used to measure joint's range of motion. Some of the assessment tools that use both quantitative
and qualitative assessments include RULA. RULA is divided into three developmental phases
that define and determine the wellbeing of an individual in terms of their working posture, the
scale of action system and the scoring system. Working postures are divided or a classified into
the arm, wrist, neck, trunk, and the legs. This division helps in the application of the scoring
system, which classifies the activities of several body parts in accordance to their application of
angles.
The NOISH revised lifting equation apply to be a valuable tool to calculate the
recommended weight limit (R WL) through the incorporation of a multiplicative model providing
weighting for each of six task variables. The equation is represented as R WL = LC x HM x VM
x DM x AM x FM x CM. Among other identified assessment tools include ergonomics task
analysis worksheet. The ergonomics task analysis worksheet is an assessment tool that helps to
evaluate, identify, and control/eliminate the risk factors of ergonomic. The ergonomics task
analysis worksheet provides information about the risk factors of a task conducted by an
individual rather than a group of individuals. This research looks to quantify musculoskeletal
disorders in electronic frame manufacturing while workers perform inspection tasks.
39
40
Chapter III: Methodology
The purpose of this study is to determine the extent that ergonomic risk factors are
causing the occurrence of upper extremity musculoskeletal injuries/illnesses among photo-etch
operators. The focus of this study was to perform a comprehensive review of Company XYZ's
OSHA 300 forms, determine the recommended weight limit for materials using the NIOSH
Lifting Equation, and analyze the workstation using the Rapid Upper Limb Assessment (RULA),
as well as an ergonomic task analysis worksheet. This chapter explains the steps that were used
to address the research goals by providing a description on how the subject was selected. Also,
this chapter will discuss the tools that were used to perform this research and the procedures that
were used to collect the data. A description is eventually provided on how the data was
analyzed.
Subject Selection and Description
At the worksite, the worker was informed of the purpose of the study in order to be
video-taped by the management of Company XYZ to analyze the awkward postures. Since the
worker and researcher were working at Company XYZ a consent form was not required. The
video-tape was maintained in a secure locked office cabinet at the company after the task was
analyzed. The Human Resource Department of Company XYZ provided the researcher with the
requested OSHA records of injuries and illnesses without the workers' names or any other
personal identifier information.
Instrumentation
In this study, the RULA worksheet was used to determine whether or not awkward
postures were associated with the task. Also, a video-recorder was used to record the task in
order to gather visual data for future analysis. In order to measure posture angles, a goniometer
41
was used in conjunction with the video recording of the task. Based on various forms of data
that were collected on the task, the NIOSH Lifting Equation was used to calculate the
recommended lifting weight and the lifting index. Also, an ergonomics task analysis worksheet
was used to assess a variety of musculoskeletal exposures that the RULA worksheet wasn't able
to critique.
Data Collection Procedures
The company supervisor used a handheld digital camera to film the procedure and
primarily focused on the worker's shoulder, neck, wrist, and elbow areas in order to provide a
view. The data was collected by reviewing the video recording and identifying the awkward
postures that were associated with the shoulder, neck, wrist, and elbow. Observational
techniques were used to gather information and evaluate the work/task.
Ergonomics task analysis worksheet. The entire task cycle was observed in order to
be familiar with the working practices and postures. All risk factors that were involved in
completing the task such as repetition, posture, yibration, reach/proper height, force, static
loading and fatigue, pressure/contact stress, lifting, material handling, and environment were
recorded and scored in reference to the drawing which most resembles the task being analyzed.
Then the risk factors were totaled to rate the task from either an ideal (1, 2 ... 30), warning level
(lA, 2A ... 30A), or take action (lB, 2B ... 30B) standpoint.
Rapid upper limb assessment (RULA). The RULA form was used to evaluate the
postures that are associated with the work/task. Each part of the body was scored in a manner
which depended on the posture level and occasional body adjustment which was required. The
total score was compared to the action list where a score of 1 or 2 means acceptable posture, 3 or
42
4 indicates that a change may be required, a score of 5 or 6 means that a change should be made
soon, and a score of 7 means that a change should be performed immediately.
NIOSH revised lifting equation. The recommended weight limit (RWL) for each
lifting-based task was calculated through the incorporation of a multiplicative model which
provides a weighting for each of six task variables. The weighting as described and presented by
the equation is meant to decrease the loading constant (LC) which represents a maximum weight
of 23 kg or 51 lb that a person should lift or lower. The equation is represented as RWL = LC x
HM x VM x DM x AM x FM x CM. The lifting index (LI) for the analyzed task was calculated
by dividing the load weight by the RWL.
Data Analysis
The video-based data was analyzed by using a goniometer which was used to measure a
given joint's flexion or extension angles. It is an appropriate device used in the determination of
required range of motion. In the determination of body part range, the goniometer must be used
with a video-recorder or digital picture to track the exact range of motion. The video-recorder
was used to provide a visual representation of the task's postural angles. The hinge part of the
goniometer was placed over the joint in question and one stationary arm was placed along one
body segment while the other movable arm of the goniometer was attached to other adjoining
part of the body. Also, an OSHA 300 form was analyzed by focusing on the past
injuries/illnesses rate ofMSD from 2003 to 2011 in comparison to non-ergonomic incident rates.
Company XYZ has provided the researcher with the incident record without including the
workers' name-based information. The workstation and common risk factors such as (posture,
force, repetition, duration, and temperature extremes) were analyzed by using RULA assessment,
NIOSH lifting equation and ergonomic task analysis worksheet. Also, a basic form of
descriptive statistical data (such as percentages and total numbers) was used to discuss the
collected data.
43
44
Chapter IV: Results
The purpose of this study was to analyze and identify the ergonomic risk factors that are
causing upper extremity musculoskeletal injuries and/or illnesses among photo-etch operators at
Company XYZ. The goals of this study were to:
•!• Determine the frequency of ergonomic-based injuries and/or illnesses through a
comprehensive review of Company XYZ's OSHA 300 forms.
•!• Determine the recommended weight limit for materials and equipment that the photo-etch
workers manually handles through the use of the NIOSH Lifting Equation.
•!• Perform a comprehensive workstation analysis using the Rapid Upper Limb Assessment
(RULA).
•!• Perform a comprehensive workstation analysis using an Ergonomic Task Analysis
Worksheet.
The methodology used to collect data consisted of gathering video recording and still
photography in conjunction with using a goniometer to measure a given joint's flexion and/or
extension angles. Also, a comprehensive analysis of Company XYZ's OSHA 300 forms was
performed by focusing on the past occurrence of MSDs from 2003 to 20 11 in comparison to non
ergonomic injuries and/or illnesses. The workstation and common risk factors including posture,
force, duration, temperature extremes, and repetition were analyzed using the RULA assessment,
the NIOSH lifting equation and an ergonomic task analysis worksheet.
Presentation of Collected Data
Objective one. The first goal of this study was to determine the costs and frequency of
ergonomic-based injuries and/or illnesses through a comprehensive review of Company XYZ's
loss records and OSHA 300 forms. For this goal nine years worth of data, from 2003 to 2011,
45
was collected for comparison between ergonomic and non-ergonomic incident costs as di splayed
in f igure 4.1.
$350,000.00
$300,000.00
$250,000.00
$200,000.00
$150,000.00
$100,000.00
$50,000.00
$0.00 2003
Incident Cost Analysis
2004 2005 2006 2007 2008 2009 2010
• Non-ergonomic incidents • Ergonomics incidents
Figure 4.1: Incident cost obtained from Company XYZ's injur-y records.
2011
Figure 4. 1 indicates that the overall ergonomic incident costs appear higher than the non
ergonomic incident costs, with a total of$ 237,939.06. ln 2003 and 2004, the non-ergonomic
incident costs were higher than the ergonomically based costs. ln 2005 and 2006 the ergonomic
incident costs increased significantly. The ergonomic incidents percentage of the total incident
costs were 57% during 2005 and 2006, as compared to 38% during 2003 and 2004. Company
XYZ experienced a general decline in the costs associated with ergonomic injuries after 2006,
although the loss costs began to increase again after 2009, a fact apparently related to the
company's overall increase in component production rate. Based on an analysis of Figure 4.1, it
appears that non-ergonomic injury losses were more prevalent during declining production
46
periods of2003, 2004, 2008, and 2009, than ergonomic injury losses. Notably higher
ergonomic-based losses occurred during the increased production periods of2005, 2006, 2007,
20 I 0, and 2011 , and therefore, Figure 4.1 displays an overall view of how Company XYZ was
financia lly impacted by ergonomic-based injuries.
Figure 4.2 provides details which identify the various risk factors that most likely
contri buted to the ergonomic-oriented injury costs that Company XYZ experienced from 2003 to
20 11 .
Ergonomic Risk Factor Cost Analysis
$250,000.00
$200,000.00
$150,000.00
$100,000.00 - ·-..
$50,000.00 -- -
$0.00 i Jl J It •~ II ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
Years
Figure 4.2: Ergonomic risk factor cost analysis.
-
2'-4 1%
• Not Identified
11 Awkward Posture
Bend/Stretch
liil Excessive Force
II Lift/Push/Pull
Repetitive Motion
u Static Position
Figure 4.2 displays the suspected risk factor costs for calendar years 2003 through 20 11 .
The costs of li ft/push/ pull risk factors amounted to 4 J% of the total while repetitive motion risk
factors accounted for 35% of all costs during this time span. Additionally, bend/stretch risk
factors totaled 11 %, awkward postures were responsible for 7%, excessive forces caused 3%,
static positions accounted for 2%, and not identified risk factors were related to 1% of
ergonomic-based losses from 2003 to 20 11. Note that repetitive motion-based losses appear as
47
the most prevalent types of injuries during calendar years 2003 through 2005, although
beginning in 2006, the occurrence of lift/push/pull and bend/stretch risk factors losses appeared
to be more significant.
Figure 4.3 below displays the occurrence of ergonomic risk factor-based cases which
were obtained from Company XYZ's OSHA 300 logs. This graph demonstrates that for the nine
years investigated, the number of injury and/or illness cases involving li ft/push/pull risk facto r
totaled 33% and those related to repetitive motion risk factor accounted for 43% of the total
number of risk factors. During this same time span, the number of bend/stretch accounted for
11 %, awkward postures caused 7%, and excessive force, static position, and not identi tied risk
factors as a whole accounted for 2% of the total number of employee injuries and/or illnesses.
The year 2003 reveals a significantly high number of cases as well as costs involving repetitive
motion risk ractors.
Frequency of Ergonomic Risk Factor Analysis 30
25
20 !- --rJl
"' rJl t'S C,l
c... 15 0 1-- -"" "' .Q
e = 10 z -I- - ·- 1-
---5 1-- 1-
0 ~~~ 3 • I 11::
2003 2004 2005 2006 2007 2008 2009 2010 2011
• Not identif ied
11 Awkward Posture
w Bend/Stretch
Iii Excessive Force
Lift/Push/Pu II
u Repetitive Motion
w Static Position
Figure 4.3: Frequency of ergonomic risl< factor cases obtained from Company XYZ's
OSHA 300 log.
48
A comparison between Figures 4.2 and 4.3 indicates that the number of repetitive motion
cases generated loss-costs of over $50,000 in each year from 2004 through 2007. During the
years 2008,2009, and 2010, Company XYZ experienced a decline in the number of injury and/or
illness cases involving repetitive motion risk factors to lower than $50,000 for each year.
Despite another decrease in total repetitive motion cases in 2011, the injury costs increased
approximately $90,000 that same year, likely indicating an increase in the severity of these fewer
cases and rising medical costs. Although the number of injury and/or illness cases involving
awkward posture risk factors increased from 2003 through 2006, these injury and/or illness costs
decreased to lower than $50,000 per year. Conversely, during 2007 and 2008, the number of
injury and/or illness cases decreased, yet the injury and/or illness costs increased more than
$50,000 in 2008, again likely indicating the severity of these cases and reflecting rising medical
costs. Since Company XYZ experienced zero injury and/or illness cases involving awkward
posture risk factors from 2009 through 2011, it may logically be concluded that the company
instituted an effective control program to eliminate awkward posture risk factors by either
training workers in proper tool use and body mechanics within the workplace or else redesigning
the workplace and tools.
Figure 4.4 below displays an analysis of the frequency for both ergonomic and non
ergonomic injuries. The occurrence of strain/sprain injuries correlates with an increasing
frequency of ergonomic risk factors which are related to lift/push/pull and repetitive motion. As
production rates increased, the number of injuries became elevated. These loss totals indicate a
need to further investigate the root causes ofthese incidents and thus provide Company XYZ's
administration with a starting point for post-loss review, planning and eventual implementing
changes to minimize these costs.
60
50
~ 40 'I: = . .., .e ~ 30
10
0 J·~
Frequency of E rgonomic and Non-ergonomic Injury Analysis
--
-- --
-- -- --
--
-• ia.. d ·- I
-- - -
II • •
li Strain/Sprain
II Internal Injury
u Bruise/Bump
II Headache
• Hernia
Personal Medica l Condition
• Cut/Scratch
u Difficulty Breathing
2003 2004 2005 2006 2007 2008 2009 2010 2011
Figure 4.4: Frequency of ergonomic and non-ergonomic injury analysis.
49
Objective two. The second goal of this study was to determine the recommended weight
lim.it for materials and equipment that the photo-etch workers manually handle tlu-ough the use of
the NIOSII Lifting Equation. Table 4.1 represents the data collected and analyzed using the
NlOSH lift ing equation.
Table 4.1 : NIOSH lifting equation.
R WL = LC X liM X VM X DM X AM X FM X CM
RWL LC liM YM DM AM FM CM RWL 51 lbs IOIH l-(.0075[v-30] .82+( 1.810) 1-(.0032A) Table 2.2 Table 2.3
RWL 51 lbs H= IO in V = 14.5 in D= [ 14.5-30]
A = 0 dcg 0.85 0.90 = 15.5 in
RWL 51 lbs I 0.88 0.94 I 0.85 0.90 RWL = 32.27 Ll = Load weight I RWL = 15. 18 I 32.27 = 0.47
50
Each value in the NIOSH lifting equation represents:
•!• LC, Load Constant, set at 51 pounds, the maximum recommended weight for lifting.
•!• HM, Horizontal Multiplier, set at 10 inches, the horizontal distance ofthe load from the
spine of the worker.
•!• VM, Ve1iical Multiplier, set at 14.5 inches, the vertical height of the hands above the
floor lifting the load.
•!• DM, Distance Multiplier, set at 15.5 inches, the actual distance that the photo tool
vertically travels during the inspection.
•!• AM, Asymmetric Multiplier set at zero, the angle between the sagittal plane and the plane
of asymmetry. This means that the worker's spine was not twisted during the time that
the photo etching process was analyzed.
•!• FM, Frequency Multiplier, scored at 0.85 and was selected from Table 2.2. The lifting
frequency was 0.2 since the worker was lifting less frequently than once per five minutes
during a work duration of more than 8 hours.
•!• CM, Coupling Multiplier, scored at 0.90 and was selected from Table 2.3. The coupling
was determined to be poor since the photo tool has less than optimal design and the
vertical height is less than 30 inches.
•!• Load Weight, set at 15.18 pounds, the photo tool's weight.
Using the NIOSH lifting equation, the calculated recommended weight limit (RWL) of 32.27
pounds for the photo etch tool manual handling process is placed in a fraction format with the
photo etch tool's actual weight in order to calculate the lifting index (LI). In this case, the LI
equals 0.47, which is a level that would be safe for most industrial workers.
51
Objective three. The third goal of this study was to perform a comprehensive
workstation analysis using the Rapid Upper Limb Assessment (RULA). Recorded video, still
photos and a manual goniometer were used to evaluate worker postures as they performed the
tasks associated with photo-etching at Company XYZ.
Manual goniometer. The goniometer utilized the recorded video and still photos gathered
as part of the RULA process to measure the various joint ranges. These ranges represent the
flexion and abduction postures occurring while the worker performs the photo tool inspection.
The joint range measurements include:
•!• The neck (cervical spine) experienced flexion of35° during the entire photo tool
inspection task.
•!• The trunk incurred flexion of20° to 30° during the entire photo tool inspection task.
•!• The elbow experienced flexion of 45° during the entire photo tool inspection task.
•!• The shoulder incurred vertical abduction of 4Y to 90° during the entire photo tool
inspection.
Utilizing the video footage and still shots to perform the goniometer measurements
provided the data to create RULA scores. Table 4.2 displays the RULA scores collected from a
visual analysis of the photo-etcher workers who were performing the inspection task.
Table 4.2: RULA scoring table.
RULA Upper Lower Wrist Wrist Neck Trunk Leg Neck, Final Arm Arm Score and Arm Score Score Score Trunk, Score Score Score Score &Leg
Score
Inspecting 4 2 3 7 3 3 7 7
photo tool
52
Table 4.2 presents the scoring results of workers performing the photo tool inspection
process. Since the process associated with rotating the photo tool requires raising the upper arm
higher than 90°, the upper arm score is determined to be 4. Holding the magnifier for inspection
requires a flexed lower arm position of more than 100°, thus resulting in a score of2. Touching
up the photo tool image to repair any defects demands that the wrist be flexed and extended
approximately 15°, therefore the applicable score is 3. The combined wrist and arm score
calculated yielded a 7 on a scale of 8, which indicates significant risk for injury to the upper
extremities (see Appendix B).
With regard to the upper and lower spine positioning, the neck experienced flexion of 35°
while the worker inspected the photo tool used the magnifier, thus resulting in a score of 3.
Since the trunk was flexed between 20° to 60° during the inspection of the photo tool, the trunk
score is determined to be 3. The legs were supported while the worker sat during the inspection,
thus yielding a leg score of 1. A calculation of the preceding scores equals the final neck, trunk,
and leg score a 7 on a scale of 7, indicating significant risk of injury regarding the identified
postures. The overall final score on the RULA of 7 indicates that the task demands further
investigation to implement changes and therefore eliminate or minimize the injury risks of the
workers.
Objective four. The fourth goal of this study was to perform a comprehensive
workstation analysis using the Ergonomic Task Analysis Worksheet (Appendix A). This
worksheet offered a way to evaluate, identify, and control the ergonomic risk factors scored in
reference to drawings most resembling the task being analyzed. Figure 4.5 displays the summary
of the completed Ergonomic Task Analysis Worksheet, where the first column indicates ideal or
53
acceptable work conditions, the second column is considered a monitor or warning situation, and
a third column represents conditions which need immediate remedy to prevent injuries.
J.
4. llead And ncc:k Mt- UJJfi.Qhl o~nd ttralghl. (Monftor It hc~d ;md nc~ •rtt bunt rorwoud ~ houtsfday. )
11~••1 ood n~<k •r• h'l/)1 M•k· (Mf!" / r<>t H • 10'; t ake ocliot' II ~10',) Head~ :tn<;l ncck_AJO bont_,~·!.a...(~r if~ 20•; tak, P'll~n U ,.2:0'.)
~<L••.1a ..!!!'!!< >'I• twlslln.!J._(Mottllor If • 20'; take ottior!.JI •20~
~. Ha~~(pal.!n!i) -.w..vW.!S~lh.J~O,!J]t<rc: H h;m dy,: mt"tL• 2..9'i tf'l\(_nc;t((Jr~ U ~ndJ.,!.2jll!9,,.2:0',) 6. \'/rls.t.s 1ue Jtrftlg ht . (MonftDt tr ""' ''u oro bent, e.torl~lort/ftt"XIQn, • 20' (ur 5·10 t irlluS/ru iriute; r()J..O tttt(on U
bont •20' 01 ~Jg_ti'!]_~J/J!!J.!!J!.!!.}. ____ ------------Wris.ts mow &ldew~tyl, ult~oJr/•~dlnl. (Nanllol U < zo• 11nd ~·lD tirM,/mlnute; loAtr ocrlnn If bant >2.0' or .. Jo llmrV~t~lnu\&) __ _
Vlbri'lt1on t. No b•!!Jl...!ll..i'!.!JWIJb-t·•ti~(Mqeii<>LJI' ~~~•loool: to~-. action It cooll•••tJ 8. Na wht)1o .. • body vilJt.i\_iqrl. (tr'!ni(.q_r ( O~~UJI()rro\t; tnb n~inu U r;onu.:wL.,) --
Rea<h 9. 1\tnr\ pus,t lon6td a\ ttlbuw lvvtl. (Morlflor It up La ~ 5· or fl'equanlly oul ot Ide• I
ho~,t r'/Jt~lJ!:rkJLe(l[~I.LiL·'!!!ILA!OJ~~rwa~~.~'...i~~~:tn JY ..... RHJ "l..=..._""'"'""""-:.0.-""""-'-"'"'U----1 AuM bnd, (MDnftOf tf ftMU bac\c up tO 20' botwcrt~n 2 .. ~ CimrJjmtnulv !9r "\ore th-_n ~ hour~$/Cf4y; CttN q$_tion tr :um' b.r£!..!:.2~ur.J:.1J I11Jes./mtnut_Q for mort thaJL.l_l.tou_nLd~.)
FlbowJ bont upward, (Moni tor U ~lbo<Ns benl up to 2Str. abo~ or below hf(.'Al uo,h.foo ~4 hOUh/d:.y; ttJh· !l!l[oa If bgn\ Yl!~l~b~vo_Q!J!!!Qw ld••l po•ltion .. }J"'u•</doy.) __ Elbow& 01woy from body. (Mom'tor If ol.betws ono up lo 4S ' AW•lY from body • " hours/dey; tnAt octron If clbDwl lU~ a.o'l'j' JW.!-}1. fe1)~~1 h.2ill.V~.vJ__ -;:-;;;;-;;-;:~;;;-;:r.;,j:;;;;-;;
tO. No twinlno. re~chii1D or btndir1g .. twi\t,ng/frr,et1Hvt.!. (MtMitar n tw!o.t lny up to '•5' nr ?. '• toko oqftm If • 4a ' 9f •4 tlruct/minujp..~)1 ___ _
fOr<e
Rc!Olchlng/bcndfng forward. (/tfonlt.ot H bcndfn9/f~dChtuu rorW41td up lo .45' Ot 2 ~4 h n /dny wfnut ~upfiort~ tpk~t action !f ~~f o' >1 Um\1,/mlnult-_or •2 htS/dl'_y ~r"-"'U>""''!!.l.!l-----1 Reach1no/bendlno to tht- ~ldt. (Mcmllur tr up lo '.0' or 2· '• thtH~~/tnlnul•; tCJ,_q ortloo H •20 ' or )II" !lnWml~uJ!.l------------------
ll. Objc"ll tHtvd by h iJOd weigh hH; . ., than ono pound. INo/1/tot lf oblot.u .- 1 lb. ft te Ufl-:tl up to 20 Jimct.,/trnur; lflkc n(llQtt U:_QbjacU: wolgh ~1 lb. Cll.._U tlnD oq.ur~ •~0 t!n>o~(ll(OJ.I.r·L---------~
12. ObJacts Uftitcl by UU! btu~ic W(lfg h lUI liHm 5 pounds. ( MOt}{I(JT ff Obj~Cts ~rgh S--2~ !bJO, or lifting Ot(UI~ Yp to 20 tim.esLb~our; l okD_ttcCfon If ot.>j~Cl! ... ~!nlt. ... !: .. 2...!...!b~ .. _g,r_tl~ ocwrt 1!'?'0 Umto,fhn,n,)
13. No pinch o.aip u'cd. (MorJitor uso of plnth g rip with ~ 2 lbs. of fc rca : tnk• nction U pfnch grip with ~~ t b::. or ~..!.> u•ud.) -------~.i!!£tu1Liv..Y••.d. (~J!"il.c1f.JU!Igllll:i_!o.IW:i'.!!!Sl..l£A• ortloUf..e~rorno\y_)'o'l__<!!:}
1/.i. Powar grlp usad w\th no tore~. (Monitor If powQr g•lp with -c 10 tb\. fore• ls. liS()d .Qnd ro ro 01rm ~s__::_.5lbS.J tgkt! ac:tto_n U .,..PO)Y_ltf grip with ~lOjb\, fnt« h '"''d. _pnd~f'il_!t'Mm _ru.1tlnn (Off(! '1•5 " '.1!1-----l
l'l, fnl,rq h<lnd contro ls ttlggcr, (Monitor 1t thulil b cont1ols;. to~ tttfJO" If .flrt!)Hf l"tl "-"·"-'"<'"'--:-:-:-----j 16, TOOI.l Or objcC1'1 hi'JYO IOUIIdad, padd~d hand l,c), (J.ron((OJ If h:.ndlCS M(t o1WkW~.trd;
, :tndl('t or t'landlc.\ _co~~n!fll!.eJ:n..tc;!.)~-~-:-"7':"-----17. Glove-' do not n<'cd t o bf" wnrn "' •ny th110. (N4>nfrCJr " Rlovcs Qf'(! nctded but Ht wcH.z toh uctiM1 H ytovct
filRo~~~---------------------------------St at1c loAding ;~nd Fatfguo 1&. Con~t;,nt, posltioll. lool or objlt~ b hrtd I on thi\n 6 .t.OUH!di. (Monit or 1f held bclw~en 6·10 second'; cok~
(ICf/011 tf tH'~~ .,~-
19. t~J!_l~Jul 2S'1. ~.!..!!!!..!.!,ik tr. rt=pctltlv~. (Mo11i{or tf 2S 'lO.,.~ rqpctlt\va; (p.C.o actfn_Q ~.2!!:....!.s:Pq!.itlv".j
Prtuur•/ConUcl StreujRepaottd J mpocu to. No tonl.at l/frnp.1c l uuut (MtMitlJt H U(ctuion.tl tm:U Vf¢ Ot body p)ttt 1,. u1ard ,,, hlmmt r -r ~ hn~ttrS/di'y;
lOb tKlfOII 1.f C_(!]U.t t'lt\! prtH'Wr~ Ot boriy p~nt h mrd _,,_ h o'IIJHIWI ~~u.!.U~.:ty,)
LUling ond Molerfats Hondllng ZJ. No Uftfng or lowt •lng ol m•lariai"J. (Momtor U oc:chfon•l anrl/or no mont lhi'n 20 tlrnu/hout; (oAa artlon U
s_nnst•nt •lnd/or grutN than 20 ttmeJ/hOU!·----- ----22. No pushing nr pulling or molorlol.s. (MOI>itor rr pu•hlng/pu\llno 10-50 c•rt•/shln; ton acti<Jn If ""''""'YII>UIIIIII9
~'2..WI.lbl!l!l.J -23. SHghl roree if rqquhod to pu'h or pull mnlori~l'!i . (Mo11ltor rr r~~odemtc force h roqulrcu1: toflv oC1fcn It hfgh
fore• Is !!!lll!w~.) Envitonme nt
Z4. Worker h6li_cftfl!!_~9JO,Ol(OI OV\'I!.YfOrk~lilCO. (Mo~~O!J<"aJ.Jnu. s~Ait!_~troli toA.u_ Oft(o:~ "..;::'":''"""~"",=->;"':";':"! 25. IJ.Qhl!Jl!IJV!I~Rll>•Ur..ii.•'U•t!<.._@nitot)[Jjig)tlly_tqsul•J~ or brl!lll\; lql.v. ac@n II •!inlnrnnlly too 7""-7~:-""-=-J 26. Tomp•roturg h comlort ablo. (Monltot If lllohtlv too ~~ ur hol:.J!>A• octlog U_slgnlll<ant\y_loa cq!d or hot.) 27. ~o~~t. (Monitor if \l~.9h)ty loa no{!y; <gAtt nsCI£!1 I{.Jj~~~-:---:---:-
28. Ooerlng provldo.s oood t rO<\Ion. (Mollll£!.illl09,tlng Is >li!J!>Ijy \llpr>'<!)l; l!!!:!,~·.~~·,.:.o..J~""'"":LII~=~u~l!.l'.l!="'-1 29. Flooring fs lurfldantly p.O:ddod to rallovo Jtrass on b11ck 11nd le:Q!i. (Honf tor If 11fghl slrtu to buk and
!Jctlon I~ moderAtely .to extreme. Sl!,!.s,__J_ _.. --- ~-:-:---1 10. Roor m 1\i iltiU provldtd. [mp1oy.v c:.-n ~l~otniltO lurtwc.on J'ltlno 11nd !itlndlng. (Monitor If ~rnplt>yet ls '
to SOY. of t hUt without floor mats or oth(lr 1trtu •~lid for bl'lck Dnd leg'; loA.t- oct/on 1r standing "''Qff• of w\U1out floor "'·'h or oth~t teUef rot bn~k .tnd
[I] 9
?
lEI
"' !ill G:Q
l2
fffi J
8B 5
1G
17
[ill I ?
IE]
21
~ [ill
~ l!l!l 27
lrn [ill
[lli
111 16
211 2 9
711
M
911
00
9C
00
l Oll
I221D IOC
Il l\
[ill) ll/1 nn
14/1
I M
IGA
~
l OA
191\
2011
~ 2211
llll
z•" 25A
26A
[ill] 2811
2911
3011
16
@] loO 4(
1,0
58
61\
GB
76
8~
96
I OJ\
10U
lOC
t lll
128
131\
138
1711
1.011
21B
22B
2411 Ull 2611 276 280
296
JOB
Figure 4.5: E rgonomic Tasl< Analysis Worksheet Summary.
54
As presented in Figure 4.5, the repetitive risk factor scored ideal, indicating no repetitive
work was occurring. The posture risk factor scored ideal for standing, at the warning level for
sitting, and in the take action column for the head/neck. The hand and wrist postures scored in
the ideal column. The vibration risk factor was scored as ideal since no vibration exists. For
reaching, the risk was assessed in the take action column because the arms reach forward more
than 45 °, the elbows are flexed more than 25% above the ideal position and the elbows were
more than 4Y away from the body. The score was ideal with regard to twisting, although the
force risk factor was scored at the warning level column because the object weighs between 5
and 25 pounds. The pinch grip score is ideal since no pinch grip is required. The take action
column was selected since the object has no handles. The task requires gloves to be worn, and
the gloves fit well, therefore, the force should be visually monitored to control slipperiness of the
photo tool. The minimal presence of static loading scored ideal, but since the task is repetitive,
fatigue was selected as a take action column. The lifting was determined to be at the warning
level since the photo tool needs to be rotated during the inspection process. The environmental
risk factors score was considered ideal for workplace control, lighting, and temperature;
however, the workplace is somewhat noisy and therefore could also be monitored. The floor
mats are provided to relieve stress on the back and legs, and therefore the score was dete1mined
to be ideal.
Discussion
The results of the data collection used in this study indicate that there are various risks
present when workers perform the photo tool inspection at Company XYZ. Although Company
XYZ has implemented engineering controls and modifications to the workstation, the inspection
task still poses a high risk to the workers' upper extremities. Company XYZ does not utilize
55
administrative controls to deal with long shift work (up to 12 hours) and the limited number of
workers who are qualified to perform the photo tool inspection. An in-depth discussion of the
RULA assessment, NIOSH lifting equation, ergonomic task analysis worksheet and the review
of the OSHA 300 log will illustrate how the collected data from each data set closely correlates.
The RULA form was utilized during the inspection of the photo tool as well as in
conjunction with the video analysis. The RULA score of seven directly correlates with shoulder
abduction and neck flexion during both the rotating of the photo tool and holding the magnifier.
The worker's need to lift higher than the shoulder level identified that the upper extremities are
at risk of developing a MSD as a result of elbow flexion and arm abduction away from the body.
Additionally, flexion of the neck up to 35° indicates that the cervical spine is at risk of
developing a MSD and further investigation should take place. The risk factors identified
through the assessment correlate with the information discussed in Chapter II of this study. The
results of the RULA assessment indicate significant risk exists workers developing CTDs,
therefore, implementation of changes in the near future would protect workers and minimize
Company XYZ's potential loss costs.
The NIOSH lifting equation was utilized to determine whether the lifting technique
possesses the potential for spine injury. Calculating the lifting index (LI) provides an estimate of
the level of physical stresses associated with manual lifting. Waters et al. (1993) identified the
goal for designing lifting jobs is to achieve a LI of one or less. This study found the LI for photo
etchers performing the lifting of photo tool process at Company XYZ scored at 0.47, thus
indicating the lifting of the photo tool during inspection is relatively safe.
The OSHA 300 log requires employers to report work-related deaths, injuries, illnesses,
medical treatment beyond first aid, days away from work, or job restrictions or transfers.
56
Reviewing injury cost data and the OSHA 300 log forms, this study discovered that the total
number of ergonomic-based incidents occurring from 2003 to 2011 represents 53% of all of the
organization's employee-related losses. However, this percentage was not specifically related to
the photo tool inspection task. The higher production demands were obvious in the years 2005
and 2006, and directly correlates to increased costs associated with ergonomic injuries. A
general decline in costs associated with ergonomic injuries after 2006 once again began to
increase after 2009, apparently related to the company's overall component production rates.
High incident costs ofliftlpush/pull and repetitive motion, 41% and 35% respectively,
and frequency of lift/push/pull and repetitive motion, 33% and 43% respectively, indicate
negative financial impacts which were absorbed by Company XYZ. When the production rates
decrease, the non-ergonomic incidents costs exceed the ergonomic incident costs, and when
production rates increase, the ergonomic incident costs exceed the non-ergonomic incident costs.
It could be that the Company XYZ increased the production too quickly and the workers are
unable to maintain the increase in production due to either improper training and/or because the
workplace is not correctly designed/prepared for the given task. The aging workforce may also
play an important role since the workers' average age is 50 years and the working time exceeds
10 hours per day. A strong correlation exists between the adverse work activities that the
workers are required to perform and the types of cumulative trauma disorder losses that the
company is experiencing. Roughton (1997), identified this type of information as a useful tool
for a company's management to review existing loss-based data. Through careful review of
records, management may evaluate and develop the company's safety and health standards,
identify and evaluate workplace hazards, and perform risk assessments to identify injury and/or
illness causes in order to create prevention methodologies.
57
The Great America Insurance Company ergonomic task analysis worksheet identified the
presence of neck flexion, elbow flexion, unsupported arms, and shoulder abduction postures in
the analyzed photo etch inspection process. Many of these risk factors have also been
established by NIOSH and OSHA as contributing to the occurrence ofMSDs. It is expected that
Company XYZ will use the previously mentioned risk assessment information to evaluate and
control the applicable ergonomic risk factors.
Chapter V: Conclusions and Recommendations
The purpose of this study was to analyze and identify the ergonomic risk factors which
were causing upper extremity musculoskeletal injuries and/or illnesses among photo-etch
operators at Company XYZ. The goals of this study were to:
•:• Determine the frequency of ergonomic-based injuries and/or illnesses through a
comprehensive review of Company XYZ's OSHA 300 forms.
58
•:• Determine the recommended weight limit for materials and equipment that the photo-etch
workers manually handle through the use of the NIOSH Lifting Equation.
•:• Perform a comprehensive workstation analysis using the Rapid Upper Limb Assessment
(RULA).
•:• Perform a comprehensive workstation analysis using an ergonomic task analysis
worksheet.
The methodology used to collect data consisted of gathering video recording and still
photography in conjunction with using a goniometer to measure upper extremity as well as
spine-based postural deviation. Additionally, a comprehensive analysis of Company XYZ's
OSHA 300 forms was performed by comparing occurrences of MSDs and non-ergonomic
injuries and/or illnesses from 2003 to 2011. The workstation and common risk factors including
posture, force, duration, temperature extremes, and repetition were analyzed using the RULA
tool, the NIOSH lifting equation and an ergonomic task analysis worksheet.
Major Findings
The Company XYZ's injury records and OSHA 300 logs indicate the occurrence of
strain/sprain injuries which correlates with lift/push/pull and repetitive motion risk factors. The
NIOSH lifting equation, used to calculate the lifting index (LI) score of0.47 indicated a level
59
that is reasonably safe for most industrial workers. The overall RULA tool final score of 7
indicates that the photo-etch operators' task requires further investigation resulting in changes to
the job in order to eliminate or minimize injury risks. The Great America Insurance Company
ergonomic task analysis worksheet identified unacceptable physical demands including neck
flexion, elbow flexion, unsupported arms movements, and detrimental shoulder abduction
postures which are used by the associated employees during the analyzed photo etch inspection
process.
Conclusions
The data collected for this study indicates the following conclusions concerning how
workers perform the photo tool inspection at Company XYZ:
•!• Strain/sprain injuries are the only ergonomic-based disorders which are occurring at the
photo tool inspection phase of production. Performing the photo tool inspection is a
critical task which currently requires the employees to exhibit unsupported and abducted
arms postures, improper neck flexion, and highly repetitive movements. It is reasonable
to conclude that these risk factors may contribute to the development of MSDs.
•!• Analyzing Company XYZ's injury records and OSHA 300 logs indicated that the
lift/push/pull, repetitive motion, and joint deviation/stretch risk factors from 2003 to 2011
have occurred frequently in comparison to awkward posture, excessive force, static
position, and not identified risk factors. It is believed that the rise of these risk factors
may correlate to the organization's periodic increase in production rates.
•!• The NIOSH lifting equation used for this study indicates that the amount of manual
material handling which is required for the photo-etch operators can be considered safe
for this group of industrial workers.
60
•:• The RULA tool results of this study indicate that the photo tool inspection process poses
the respective employees to a high risk of developing MSDs and therefore the process
must be further analyzed to implement changes and thus eliminate or minimize the
occurrence of identified ergonomic risk factors.
•:• The ergonomic task analysis worksheet used in this study identified that photo tool
inspection workers are usually exposed to unacceptable neck, elbow, shoulder, and trunk
postures as well as situations where the arms are unsupported.
•:• Based on the collected data from the RULA tool, Company XYZ's injury records, and
the formal task analysis process, the risk factors associated with the photo tool inspection
activity include lift/push/pull, repetitive motion, joint deviation/stretch, awkward posture,
excessive force, and static postures. Therefore, this research concludes that ergonomic
concerns are present in the photo tool inspection process.
Recommendations
Based on the conclusions of this study, following are recommendations which may
eliminate or at least reduce the exposure of ergonomic-based risk factors and the occurrence of
musculoskeletal disorders for employees who are performing the photo tool inspection process at
Company XYZ:
Elimination and substitution:
•:• Complete automation of the photo tool inspection process that aligns with another
similar process which has already been automated. This process would eliminate
the need for human interaction.
•:• Cast a metal template from the inspected photo tool's image for each batch of
product, instead of repeating the inspection process to repair the defects.
61
Engineering controls:
•:• It is recommended that management consider reducing the size of the photo tool
to enable easier manipulation by the workers during the inspection process.
•:• Use a fixed magnifier instead of moving it during the photo tool inspection
process to eliminate the occurrence of shoulder abduction and elbow flexion.
•:• Replace the standard magnifier with an electronic device which projects the
image to a screen and thus helps eliminate the occurrence of neck and trunk
flexion.
•:• Redesign the work station in order to facilitate manipulation of the photo tool in X
and Y directions, instead of maintaining the photo tool in a fixed position during
the inspection process.
•:• Allow the workers to adjust the station to within three inches below the palms of
the hands when the elbows are at a 90° posture in order to eliminate the moderate
amount of shoulder abduction and elbow flexion which is experienced by the
worker.
Administrative controls:
•:• The workers should be trained to perform the work correctly using proper body
mechanics which includes how employees should sit, lift, stand, carry, and flex
various body parts and utilize the right tools such as chairs that support the lumber
area and devices which lift parts and/or equipment.
•:• The workers should be involved in a job/task rotation system to minimize
repetitive motions and thus reduce the exposure to risk factors associated with this
task through the entire working shift.
62
•!• Modify the work-rest schedules to provide more frequent short rest breaks. Also,
it is recommended that management train the employees to perform various
stretching-based activities during these breaks to promote short-term muscle
recovery.
•!• Train workers to recognize the risk factors that contribute to the occurrence of
MSDs and various work station design approaches to provide a feedback
mechanism for input toward planned solutions which can help eliminate/reduce
identified risk factors.
Areas of Further Research
It would benefit Company XYZ to further investigate the following areas to identify and
control ergonomic-based risk factors which may be present in the photo etch inspection area:
•!• Follow up on worker concerns regarding uncomfortable neck flexion postures which are
required in the photo etch process.
•!• Execute a comprehensive loss analysis to determine the actual costs of lost and restricted
days as a result of injuries and/or illnesses which are associated with the photo tool
inspection process.
•!• Analyze the lifting techniques used during the photo tool inspection to identify safe
practices of the photo tool's rotation process.
•!• Perform in depth loss analysis to identify the reasons that non-ergonomic incident costs
exceed the ergonomic incident costs when production rates decrease.
•!• Investigate the impacts that lengthy work days (which exceed 10 hours) have or an aging
workforce as it relates to the development of MSD' s.
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2
Appendix A: Ergonomics Tasl<. Analysis Worl<.shcct
Posture (continued)
'
;
_.I Ergonomics Task Analysis Worksheet
Directions: The Ergonomics Task Analysis Worksheet provides a method for identifying, evaluating, and clirninating/controlling ergonomic risk factors. Observe sev~r~l task cycles prior to making notes or drawing conclusions. Score each risk factor (ideal, warning level, or take action) that most resembles the task you are analyzing. Once you have completed the worksheet, create an Action Plan (how to control or eliminate the risk factor). focusing on tasks from the "Take Action" column first. It is often helpful to videotape the job to facilitate a more detailed review and action plan.
Repetition NIOSH defines a repetitive task as one with a task cycle time of tess than 30 seconds or performed for prolonged periods, such as an 8-hour shift.
Posture
Standing
2. Knees are stmight, but not locked. Back is upright and straight. No twisting, reaching or bending. (Sec reaching)
Sitting ~ 3. Back and legs :
supported by comfortable chair. c .. Ji Feet are flat on floor or foot rest.
Head/Neck
4. Head and neck are upright and straight
1A. Rcpelltlve hlll!d or arm motions with cycle times of 30-60 seconds
Standing
2A. Knees partly bent.
Sitting ~ 3A. Back Is only
partially supported ·
or feet are not flat. ~Q-.
Ill. Repetitive hand or arm motions with cycle times of less than 30 seconds
28. Kneeling > 3 hrs/day
20. Using a fuot pedal ~
Sitting
38. Little support for legs and back. Feet do not touch floor.
Head/Neck
4A. Bent forward more than 20' ,. 3 hrsjday
68
Reach/Proper Height
9. Work should be performed at 90' or slightly above or below elbow level
10. No twisting, reaching or bending
9A. Am1s forward up to 45' or frequently maintained outside of the ideal position > 4 hrs/day
98. Arms back up to 20' and no more than 2-4 times per minute > 4 hrs/day
9C. Elbows bent up to 25% above or below the ideal position > 4 1m/day
90. Elbows up to 45' away from body > 4 Ins/day
lOA. Twisting up to 45' or frequent twisting (2-4 times per minute)
108. Bending/reaching forward up to 45', frequent bending (2-4 times per minute) or> 30% more than 4 hours per day without support
lOC. Bending/reaching to the side up to 20' or frequent bending (2-4 times per minute)
9A. Arms forward more than 45 • or constantly maintained outside of the ideal position > 3 hrs/day
98. Arms back more than 20' or more than 4 times per mi nute > 3 hrs/day
9C. Elbows bent more than 25% above or below the ideal position
90.
> 3 hrs/day
45' away from body > 3 hrs/day
lOA. Twisting more than 45' or highly repetitive twisting (more than 4 times per minute)
lOB. Bending/reaching forward more than 45', highly repetitive bendin~g (more than 4 times per
1 ~
minute) or more than 2 hours per day without support
lOC. Bending/reaching to the side more than 20' or highly 1 repetitive bending 1
to the side (more ~ than 4 times \ per minute)
69
Force Force is the amount of physical effort required to do a task or maintain cont rol of the tools or equipment. Effort depends on t he weight of the object, type of grip, object dimensions, type of activity, slipperiness of t he object and duration of the task.
11. Objects lifted by hand weigh less than 1 pound
12. Objects lifted by the back weigh less than 5 pounds
Duration 13. No pinch grip used. Fingers
and thumb comfortably fit around tool or object
14. Power grip used with little to no force.
15. Entire hand controls trigger
16. Tools or objects have handles that are rounded
Slipperiness 17. Gloves do not need
to be worn at any time
11A. Objects lifted by hand weigh less than 1 pound and frequent lifting (no more than 20 times an hour)
12A. Objects lifted by the back weigh between 5 and 25 pounds or frequent lifti ng (no more than 20 times/hour)
Duration 13A. Moderate pinch grip or pinch
grip with less than 2 pounds of force
r£::1D 138. Grip is slightly too wide
~ 14A. Power grip used with less
than 10 pounds of force. Forearm rotation force is less than 5 pounds
15A. Thumb activated control
16A. Awkward handles
,• ' ~
16A. Tools with ·~ "·t' ~ .. awkwa~ ~·~ N
handles ~\ \..'(\..
r---------------~~· Ch
15A. Objects with B awkward handles lJ
118. Objects lifted by hand weigh more than 1 pound or highly repetitive lifting (more than 20 times an hour)
128. Objects lifted by the back weigh more t han 25 pounds or high ~y repetitive lifting (more t han 20 times/hour)
Duration . 13A. Severe pinch grip or pinch
grip used with greater t han 2 pounds of force
~. 138. Grip is extremely wide
d:::::n 14B. Power grip used with more
t han 10 pounds of force. Forearm rotation force is
·more than 5 pounds
158. Finger(s) activated control
16B. Handles, tools or objects that concent rate force or have no handles
168. Handles t hat concentrate ~ force -~
One
168. Objects with ~ no handles ~
Slipperiness Slipperiness 17A. Gloves are needed but fit well 178. Gloves are needed but fit
poorly
70
Static Loading and Fatigue ' Static' loading refers to staying in the same p9sition for prolonged periods. Tasks that use the same muscles or
motions for long durations (6 seconds or more at one time) and repetitively (more than 50% repetition) increase the likelihood of fatigue.
Duration 18. Constant position, tool or
object is held less than 6 seconds
Repetition 19. Less than 25% of the task
is repetitive
Duration 18A. Constant position, tool or
object is held 6 to 10 · seconds
Repetition 19A. 25% to 50% of the task
is repetitive
Pressure/Contact Stress/Repeated Impacts
Duration 188. Constant position, tool or
object is held more than 10 seconds
Repetition · 198. More than 50% of the task
is repetitive
Refers to pressure or contact from tools or equipment handles with narrow width that create local pressure. It also applies to sharp corners of desks or counter tops. Impact refers to the use of hands, knees/ foot, etc. as a hammer. (Related to Force Conditions in item 16.)
20. No contact or impact stress: tools/ objects/ or workstation do not press against hands or body
20A. Occasional and minimal pressure or impact on hands or body. Hand, knee or other body part used as hammer less than 2 hours/day
Lifting and Materials Handling
21. No lifting or lowering of materials (see also Force for weights of objects handled)
Push/Pull 22. No pushing or pulling of
carts or materials
23. Slight force is required to push or pull carts or materia Pushing is preferred over
· 'ects.
21A. Occasional lifting and/or lowering (no more than 20 times per hour)
Push/Pull 22A. Pushing or pulling 10-50
carts per shift
23A. Moderate force is required to push or pull carts or materials.
208. Constant pressure or impact on hands or body. Hand, knee or other body part used as hammer more than 2 hours/day
21B. Constant lifting and/or lowering (more than 20 times per hour)
Push/Pull 228. Pushing or pulling more than
50 ~arts per shift
238. High force is required to push or pull materials.
71
6
Environment
Work Pace 24. Worker has adequate control
over work pace.
Lighting 25. The lighting is adequate
fo r t he task.
Temperature 26. The temperature is
comfortable.
Noise 27. The work area is quiet.
Floor Surface 28. The flooring provides
good t raction.
29. The flooring is sufficiently padded to relieve stress on back and legs.
30. Floor mats are provided to relieve stress on .back and legs. Employee can alternate between sitting and standing,
Work Pace 24A. Worker has some control
over work pace.
Lighting 25A. The lighting is slightly
too bright or too dark for the task.
Temperature 26A. The temperature is slightly
too cold or too hot.
Noise 27 A. The work area is
slightly noisy.
Floor Surface 28A. The flooring is
slightly slippery.
29A. The flooring contributes slight stress to t he back and legs.
30A. Standing 0-50% of time without floor mats or other means to relieve stress on back and legs.
Work Pace 246. Worker has no control
over work pace.
Lighting 25B. The lighting is significantly
too bright or too dark for the task.
Temperature 266, The temperature is
significantly too cold or too hot.
Noise 276. The work area is significantly
noisy (too noisy to carry on a conversation).
Floor Surface 286. The flooring is moderately
to extremely slippery.
296. The flooring contributes moderate to extreme stress to the back and legs.
306. Standing more t han 50% of time wit hout floor mats or other means to relieve stress on back and legs.
Comments: --------------------------------------------------------------------~~---
Note: The levels provided above are standard practices which have been accepted or established by NIOSH, OSHA, ANSH and other related organizations. Th•IOU1Hf'ltntMn f~Uon provldtd In t"l' b/KtwN Is biJud on fflfflotty outplfd J(ljt pr(Jd(cu for mlnlmlting lon In Utt dtKtibfd sltuGtionJ. In p(f111idlng svcll lfl/.,tmQrlonl Ciftot NttfrlC(In 1nJiJtDfltt Group dtJr.r not WGnanr UtDL oil pott.nUd lttmurb 01 t4rklitfoiU hDvt bftrt llv4luottd ot lhot thq con bt coniJutflfl. 11tt hi/Onnt~lion (J ,.ol fnltndtd 01 ort of/tt to wrltt /ruu!DAct/or luth ccndftfoJU 01 ~Ui'lf, 1/11 Ht~bHi()l of Gnot Amuic!ln ol'it//ot io 1ubsld!'adu Is lirnflld ~o til• tumJ, 1/mlu ond conditfom of «Cwf ftuunznc• polfclu iJJ&Jtd t.o Jprciftc lfUut'Uh.
72
73
21 21A 216
22 22A 22B
23 ZlA 238
24 24A 248
25 25A 259 26 26A 266 27 27A 278
23 28A 28R
29 29A 298
30. Floor mats arc provided. Employe& can alternate between sitting and standing. (Monitor if employee Is standing up to SO'Io of shift without floor n1ats or other stress relief for batk and legs; take action if standing >50'/• of shift without lloor mats or other relief for back and legs.
30 30A 30B
8
Action Plan Today's date: _______ _ Date Solution to be Completed --------------
Location/Department:-----------------------------
Job/Task Title: ------------------------------
Evaluator: -----------------------.------------
Describe MSD in previous 24 months: --------------------------
Task: _____________________________________________________________ _
Summary of Problem: -----------------------'-----------
Alternative Solution and Costs; ----------------------------
Recommended Solution: 1) Engineering -------------------------
2) Administrative: ----------------------------------------------------------
3) Use of personal protective equipment------------------------
Data Solution Actually Completed: ------------------ Actual Cost: -----------
Th lon prnYfll/on lrlformotlon prrwtdtd In tht. brochure (I b11~1d on grnv41tt (l(tfpttd 14~ pro¢"1/~ tnlt~lm}lfnt to# til th• ducrlbrd lfU.'fttcmr, Itt p14vl/l'ng 1vch ~riPtt1 G•'1C MttrlcM Jm11ronct Crovp docs not WDtRJ')i thot IIU p3tlntid hurd1 IH CMdft*ms htzvt "''" f"fffuattd Cl' tfroc tltty ron 6t con!NHtd. 1M llt/iHttYJtlort IJ tm inftfldtd ru n.n cj{rr to Wl'frt ltttUMttf fiN 1utlJ tMdit1oru .w
'"FaJ~J~W, rh• lio&rlity cj Grtoor Atm'tkrJn and/or Irs jllbJflfkNIIJ l1 tfmliJd to tht flf'flj, 1/ftl/t, Dltd rOI!iJI'dom of «1\Hil WvrotK'I po/kiiJ JJJulll tD Jpt('IJI( lruwtd/,
74
Appendix B: RULA Employee Assessment Worl{shcct
RUlA Employee Msessment Worksheet .. ,....,MA, ..,..,_"""""··~o~-.ww_..,. __ .,....,, c.-_,__, "'J.''~'' , .,
\ctp II Aoi/1UI li111001141KIIliM •I u.,ttll'D&I\iWVtttd. •I lftn&l\tlrPtfttdotptt\OIUM:lUD; •I
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1< ... ~ltp ~: Loot . up Pomut Sto11 ill To bid: UtLOJ '"'llti' rrou ''•ltt '"" tb""·•. locu• «on m Tal>loA
Slip 6: .\dd ~lul<lt l'l• ~••• lt pocNil.,.IOiYIU><(lt ''M IOW1111). OctCtc~Olltp!Urtd cc:n.n .&Xpt: EUIN •I
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Sltp 8: flad Ron iu T•blt C ,\64\"&.'ltl hDt!tpi '·7tf~ll14 Wnua_a4Ata\co:t fLC4 towt:~ TabltC
SCORES
Tablo A: Wnsl Posturo Score 1 2 3 I 4
~.J (,I u .... Lo- , .. , .... lA"~ A·
lol •• J
""" -I 2 1 2 I 2 I 2 I I 2 2 2 2 3 3 )
I ~ 2 2 2 2 ) 3 ) )
1-c-l 2 ) ) 3 3 3 •• I 2 ) ) 3 ) . • •
2 2 3 ) ) 3 3 • • • ' 3 • 4 • 4 • & I
I 3 3 4 4 • • I I
3 2 3 • 4 • • • s & , •• 4 4 • I s 6 I • • • •• I 6 0
4 2 •• • • • I ' ' ' • 4 4 0 ' ' e I
' 0 0 0 0 s I ' 7
5 2 0 I I 6 0 7 7 7 , 6 I 0 7 7 I 7 I
I 7 7 7 7 7 I I 9
6 2 ' • • • a 0 0 0
3 0 v 9 9 9 0 • 9
Tallie C: Nt<l bun~ .nd Ito ~<or•
j ' I 2 l I 4
2 2 I ) • • l 3 s I l • •
4 3 I l • I
l ' 4 4 • 6 6
~ 0 4 4 I • e I I I 6 6 I
•• I I 6 1 7
Scorln9: (fln.JI SOlie rrcm Taolol C) lorl•.o<~pom ..
I I ~ I I 6 6 6 1 7 1 7 1 7
1 7
) Ot 4 • "'tllor l.....t,.gobOo\, ch.lc9o mq bo oi!Odod s .. ' • lwlhtr • ......,.bOo\, ·~·-
7 ·~to ·n4"'P'4octflldi-
ITJ Final ScOfe
B. Neck, Trunk and U!CJ Analysis
Sttp9: Lo<Mt :'\tck Polirion:
··R ··n -· r,~ ~-r~ \1tph Ail).-1 Uucku "''mJ -I Ullt<ku1idtt.GdQr ·l
110910. Al;un ll w» n nm:t4 ·i ll~u\:dobo.UJ •I
Sttp II: L•C" UltJ\ ud ftu an t~nd •I lloo• •'
l)~,. 8 ·N~t POV,\tt Sco"t -- l .... I I ' I 1 I ' : 1 I
' I 1 J 1 I . ' I • • ' ' ' ' I . • I ' • , I 1 I 1 . . • I • • r . I ' • • . , r r T , I . ' , r • I
' I ' I I • I I I • I
~ 1
I
I
r 1
I I
S1tp ll: Look-up POiturt ~on lu r.,blr 8: V~ill \tiVU O"<ICIItfiH P·ll &bo\f, loclttl(Oif Ul T~lt 8
S1tp l.l: Add ~!ul<lr t'~t ~con ltpow:ua.illlym'lcOt. ~ld IOurmu), Or U' xc.oo ft9tlltdocnn ~X FH lli:l.~t• •I
Stop I~: ..\dd forwto.~d ~co1 t U lc~J "" lb1 (t:altmlrtofl ~ Iti:Jj~.tco~~l":K(ID:.rs.~'tnl) •I UI~U .a~ to ~!~' (•tJm Of rtpt11t4j •! ltiUtfckal !! l~~ffltptll!tdCtflobom •)
Sup 1~: frud Colallllll T~blt ( A~d ' ' ltu 6oo •~P' 1:-u rooM.ua ,:.d, TI'tl.tkuJLt J\<ett 11&4C.:UIItDT.Iblt C
I . r I
I
f>~kCWit ------------ RtntwK. _________ 0•10: ______ _ Mtidfd ~ ,....._, ErpoM'<I
rto..(~t<J>'"""trl"t (111)#1-IUT
75
