PRACTICE ORDER EFFECT ON BILATERAL TRANSFER

OF THE INSTEP DRIVE IN SOCCER

by

Paul A. Stumpf

A Thesis

Presented to

The Faculty of Humboldt State University

In Partial Fulfillment

of the Requirements for the Degree

Master of Science

In Kinesiology

May, 1998

PRACTICE ORDER EFFECT ON BILATERAL TRANSFER OF THE INSTEP DRIVE IN SOCCER

by Paul A. Stumpf

Approved by:

Kathy D. Munoz, Committee Chair Date

Chris A. Hopper, Committee Member Date

Kim T. Benson, Committee Member Date

Scott Nelson Graduate Coordinator Date

Linda A. Parker, Graduate Dean Date

Abstract

PRACTICE ORDER EFFECT ON BILATERAL TRANSFER OF THE INSTEP DRIVE IN SOCCER

by

Paul A. Stumpf

The purpose of this study was to determine the effect of

serial and sequential practice methods on the bilateral skill

of the instep drive in soccer. Forty-five fifth grade boys

and girls from a local elementary school were used for the

study. It was a pre-test, post-test repeated measure design,

and treatment consisted of 5 days of practice. Prior to each

day's practice attempts, the subjects were given a

demonstration of a different aspect of the instep dive. Two

variables, accuracy and velocity, were measured to determine

the quality of the instep drive. The results of the study

showed that both practice order groups lowered their accuracy

and velocity scores. The inability to produce an improvement

in skill was attributed to a change in the subjects'

technique and the scoring system utilized.

iii

Table of Contents

Page

Abstract iii

List of Tables vi

List of Figures vii

Chapter One

Introduction 1

Statement of the Problem 3

Review of Literature 4

Purpose 19

Operational Definitions 20

Assumptions 20

Hypothesis 21

Limitations 21

Delimitations 22

Significance of the Study 22

Chapter Two

Methodology

Subjects 23

Assessment 28

Pilot Study 31

Statistical Analysis 32

Chapter Three

Results 33

Chapter Four

Discussion 41

iv

References 49

Appendices

A. Consent Forms 51

B. Participation Questionnaire 57

C. Score Sheets 60

D. Instruction Demonstration 65

E. Human Subjects Committee Letter 67

List of Tables

Page

Table 1. Mean Accuracy and Velocity Scores 34 at Pre-Test and Post-Test

Table 2. Demographics of Participants 35

Table 3. Number of Years on Organized 36 Soccer Team

Table 4. Correlation Coefficients Between 39 Gender and the Dependent Variables Accuracy and Velocity in All Participants

Table 5. Correlation Coefficients Between 40 Velocity and Accuracy

vi

List of Figures

Page

Figure 1. Schematic Drawing of the Floor 30 Plan for the Assessment Portion of the Study

Figure 2. Frontal View of the Target With 31 Corresponding Dimensions of the Concentric Squares

vii

Chapter One

Introduction

Bilateral transfer is a theory regarding motor learning

that has been defined as, "the extent to which an

individual's ability to acquire and perform a skill is

transferred from a limb on one side of the body to one on the

other side" (Dunham, 1977, pg.51). This is a fascinating

theory with a number of potential applications regarding

skills that are produced from both sides of the body.

Typing, for instance, is an example of a bilateral skill, as

the ability to type on a standard keyboard requires the

fingers on the left and right hands to perform.

This theory can also apply to skills required for sport.

For instance, soccer is a game that requires both legs and

feet to be skilled at manipulating a ball for passing,

trapping, shooting, and crossing. Basketball is another

sport in which both arms and hands are vital for performing

the skills required at the higher levels of competition.

According to Parker-Taillon & Kerr (1989), the bilateral

transfer theory is not heavily contested, in fact it is

generally accepted that transfer of information does occur

between limbs during skill acquisition and performance.

Although the theory is generally accepted, researchers have

been unable to agree on exactly how the transfer of

information occurs. There are currently two popular

1

2

hypotheses explaining the bilateral transfer phenomenon, the

neuromuscular activation hypothesis and the cognitive

hypothesis.

The neuromuscular activation hypothesis suggests that

when one limb is participating in a skilled performance,

there is measurable EMG activity recorded in the non-

practicing limb. The EMG readings in the non-practicing limb

potentially represent the covert development of the motor

skill, which is being transferred from the practicing limb.

This is a peripheral information processing hypothesis.

In direct opposition, lies the cognitive hypothesis,

which suggests that transfer of information between limbs is

the result of central information processing. Information is

gathered in the brain during skill acquisition or imagery,

and can be passed on to either limb. Proponents of the

cognitive hypothesis believe they have research findings that

suggest the neuromuscular activation hypothesis may not be

the complete answer to bilateral transfer, and that the

cognitive theory is at least partially responsible for the

transfer of information. Research on two separate

experimental groups resulted in bilateral transfer being

equal between the groups--the first group physically

practiced a skill (neuromuscular activation), while the

second group only mentally practiced a skill (cognitive).

Prior research suggests that mental practice of a skill only

produces EMG activity in the imaged practicing limb. Since

3

the transfer of skill was measured equally between the two

groups, the question of whether neuromuscular activation is

the only possibility to producing bilateral transfer is a

credible one.

The inability of researchers to synthesize an acceptable

theory for how bilateral transfer is produced, may suggest

that a combination of physical and mental practice may

maximize the transfer of information between limbs.

For a theory with so much potential to increase the

knowledge base of motor learning, there is limited research

regarding the topic, and precious little research regarding

applied gross motor skill found in sport settings.

Statement of the Problem

Practice time for youth sports is limited, and the time

spent teaching bilateral skills needs to be spent in the most

efficient manner. Kicking a soccer ball for distance,

velocity, and accuracy with both feet is essential for

success at the higher levels of competition. This skill is

used for shooting, crossing, clearing, and making longer

passes. It has yet to be determined, what practice order

provides the best results in the skill acquisition for

soccer's instep drive.

4

Review of Literature

The literature reviewed regarding bilateral transfer is

filled with information that suggests that the transfer of

information does occur between limbs. However, the

literature is also filled with inconsistent findings that

would suggest further research of bilateral transfer is

necessary to more fully understand the theory.

The inconsistencies in the literature seem to focus on

practice order, direction of most effective transfer, and an

explanation as to how the transfer of information occurs. In

many articles, more than one of these factors are discussed.

For this literature review, the topics will be broken down

separately, and each topic will be discussed individually.

The majority of the research has employed the use of

novel tasks like rotary pursuit, (Dunham, 1977 & 1978 and

Byrd, Gibson, & Gleason, 1986), but there is some research of

bilateral transfer on complex motor tasks like catching,

(Fischmand & Sanders, 1991) and kayak rolling, (Smith &

Davies, 1995).

Although most research located regarding bilateral

transfer supports the theory, one study suggests that

transfer of information may not be possible for complex motor

skills like dancing or dribbling a soccer ball. The study by

Hicks, Frank, and Kinsbourne (1982) suggests that during

skill acquisition for one limb, transfer of information to

5

the non-practicing limb is blocked if the non-practicing limb

is engaged in an unrelated task.

In this study, 128 subjects were randomly placed into

two groups, an experimental and a control group. Both groups

practiced a one-handed typing exercise. During the one

handed typing exercises, the control group was instructed to

leave their opposite hand free, while the experimental group

was instructed to have their free hand grip the table leg.

The authors hypothesized that the control group would show a

significant amount of transfer of information, while the

experimental group would show little or no transfer of

information.

The results of the study agreed with the hypothesis set

forth by the authors. The control group showed a significant

transfer of information, while the experimental group had

little or no transfer take place. The authors suggest that

when the muscles that are to be involved in the transfer are

not available, the covert instruction for the movement

pattern can not take place.

These results were potentially devastating to the

possibility of bilateral transfer aiding individuals in

bilateral skill acquisition for many sport related or gross

motor skills. This study would suggest that bilateral

transfer is not possible while kicking a soccer ball with the

instep drive. Since one leg is involved in learning how to

kick the ball, the opposite leg would be used for things like

6

planting, balance and locomotion. The muscles involved in

the transfer of information in the untrained leg are

unavailable to receive the covert instruction for the

movement pattern, and therefore unable to receive any

transfer information.

Since research supports the theory that transfer of

information is possible for gross motor skills like dancing,

further investigation is necessary for a possible

explanation. Again, the results suggest that transfer of

information is not possible when the non-practicing limb is

involved in an, "unrelated activity" (Hicks, Frank, and

Kinsbourne, 1982, p. 277). It is clear that when kicking a

soccer ball, both legs are involved in the activity. Both

legs are used for locomotion and balance when approaching the

ball, but each leg has separate activities just prior to

contact. The plant foot and leg are involved in stopping the

forward motion of the body and keeping the body in balance,

while the practicing limb is the only limb involved in making

contact and driving the ball.

It remains to be seen whether the plant foot or non-

practicing limb, while engaged in an activity, will receive

any transfer of information. One possible explanation may be

that non-practicing limbs may receive transfer information if

it is engaged in a related activity. Further research needs

to be done to determine if transfer of information may be

possible and readily accepted in limbs engaged in a related

7

activity. Again, this is only an anecdotal suggestion as to

why gross motor skills can be bilaterally transferred when

both limbs are engaged in activity.

One study that appears to add further proof of the

existence of bilateral transfer was conducted by Fischman &

Sanders (1991) who studied 20 undergraduate and graduate

students at Auburn University. The study investigated

whether skilled baseball/softball players could perform

single gloved catching with both the dominant and non-

dominant catching hand. The results showed essentially

perfect performance in all conditions. Out of 1600 total

trials, only 7 balls were dropped.

The players enjoyed overwhelming success in catching

with both hands. The number of balls dropped (7) out of the

total number of trials (1600) represents a percentage of less

than 1/2 of 1 percent. This would suggest the existence of

bilateral transfer, because it is not a common practice

method to train baseball/softball players to catch with the

non-dominant hand.

One heavily researched factor in bilateral transfer is

practice order. For instance, Dunham (1977), developed a

study to determine whether the order in which subjects were

taught a skill influenced the outcome. Sixty undergraduate

students volunteered to be subjects for this study, and the

novel task was rotary pursuit. Two practice orders were

being observed for this study, serial practice and sequential

8

practice order. Sequential practice order requires the

performer to practice the skill for a prescribed period or

until a criterion level is reached, on one side, and then

similar practice is performed on the other side (RRRRR

LLLLL). Serial practice is employed when the performer

alternates trials from one side of the body to the other

(RLRLRLRLRL).

The results of the study were clear, and suggested that

the sequential order of practice was more advantageous in

bilateral skill acquisition. These results agreed with the

expectations of the author, who had drawn his conclusion from

the theory of forgetting. This theory suggests that, the

holding of conflicting events to a minimum, during skill

acquisition, provides subjects with the best opportunity to

learn. Serial practice order prescribes rotating the

practice of a skill from one side of the body to the other,

and this rotation provides conflicting information to the

learner, and blocks them from maximizing their time spent on

learning the skill.

Dunham (1978) produced further evidence of bilateral

transfer, and the use of sequential practice order on

bilateral transfer. In this study, he used 44 undergraduate

male subjects, and the apparatus was a photoelectric rotary

pursuit mechanism. He broke the subjects into four groups:

preferred serial, preferred sequence, non-preferred serial,

and non-preferred sequential.

9

The results suggested that the order of practice does

provide a significant effect on acquisition, and the more

effective practice order was the sequential method. The

sequential order provides the individuals the opportunity to

learn the task with less conflicting information.

From research closer the present day, and involving

skills that are more complex in nature, a study on practice

order was conducted by Puretz (1983). In this experiment,

the use of a complex dance movement pattern to test the

effects of practice on bilateral transfer was employed.

It is customary in dance classes for the instructor to

demonstrate simple or complex movement patterns on the right

side only, and the students in the class regularly practice

and perform the demonstrated dance pattern on the right side

only. No further class time is spent to practice the

movement on the left side, but dancers can mentally or

physically practice the movements on their own. The students

are then expected to perform the movement on the left side

without the benefit of demonstration or augmented feedback

from the instructor. This observation of dance classes

suggest that instructors of dance classes assume the theory

of bilateral transfer is valid.

The subjects for this study were freshmen through

seniors at the State University of New York, and split into

two groups, beginners and experienced dancers. The dancers

were taught two different eight count movement sequences, one

10

at a time, and from one side only. After each sequence was

taught and practiced, the experimenter instructed the

subjects to perform the movement on the opposite side, and

the results were videotaped.

The findings were significant. The results showed that

there was a significant amount of transfer from the practiced

to the non-practiced limb. This result suggests that dance

teachers have been intuitively correct in their teaching

methodologies, and that they should continue to count on the

bilateral transfer of information to aide their students in

learning the movement patterns on both sides.

Further, Smith & Davies (1995) studied the effect of

practice order on a complex motor kayaking skill. Contextual

interference can be manipulated by changing the practice

order of a skill. Like the complex dance pattern study,

Puretz (1983), the Pawlata roll in kayaking is generally

taught to criterion in one direction only. It was the

purpose of this study, to discover whether this is the most

effective means of teaching the skill.

"Context intervention literature predicts that skill

retention would be better served by practicing on alternate

sides" (Smith & Davies, 1995, pg.455), but in this case, the

study was also measuring the effects of context intervention

on skill learning.

There were 16 undergraduate student subjects from the

University of Wales, and they were split into two

11

experimental groups. Group 1 was the low contextual

interference group, while Group 2 was the high contextual

interference group.

Kayak rolling consists of a number of sub-components,

and is therefore conventionally taught in the progressive

part technique. Within this technique the task is taught in

manageable chunks, and integrated as successively larger

components of the task are mastered.

The findings suggested that the group with high amounts

of interference learned the skill faster, and were also

quicker to achieve successful performance in retention.

These findings were not expected, as they suggested that

bilateral transfer was increased by randomizing practice.

It was suggested that the variation of the task required

only the transfer of skill between limbs. Since the

variation in skill was within the same generalized motor

program, this was not a sufficient difference to provide a

significant contextual interference effect.

The next topic that needs attention from the bilateral

transfer literature is the idea of which direction is the

transfer of information the most effective. In other words,

does a greater amount of information or skill acquisition

transfer from the preferred limb to the non-preferred limb,

or does information/skill transfer better in the other

direction. Most of the above mentioned studies discussed

this topic.

12

In both studies conducted by Dunham (1977 & 1978) the

novel task employed was the rotary pursuit mechanism. The

author was interested in determining whether the side of the

body initially employed during practice, would significantly

influence the bilateral acquisition. In other words, would

there be a difference in acquisition if an individual started

practicing with the preferred side, as opposed to starting

with the non-preferred side.

For both studies, the subjects were randomly assigned to

one of four practice groups: preferred serial, non-preferred

serial, preferred sequential, and non-preferred sequential.

The author expected to find that starting to practice a new

skill with the preferred limb, would result in a better

acquisition of the skill. The results of both studies were

similar, and showed no significant differences in starting

with preferred over non-preferred limbs. The author provided

no concrete evidence to explain this finding, but suggested

that the number of practice attempts may have been

insufficient to observe a significant difference.

Referring back to Puretz (1983) a surprising result was

determined. The results of the study suggest that for complex

movement patterns, there is greater transfer of information

going from the non-preferred side to the preferred side. In

other words, when the complex movements were demonstrated and

practiced originally from the non-preferred side, it would

13

appear that the transfer of information was greater, because

the overall performance was better.

Since most bilateral transfer studies have used novel

tasks to measure transfer, it is unclear whether this one

study would indicate that complex movements will normally

transfer best from the non-preferred to the preferred side.

Unfortunately, this information confuses the issue

regarding application to sport specific situations. It is

suggested, from this study, that constant repetition of the

non-preferred side is important in providing self-efficacy

toward a complex skill, which makes sense. This study also

agreed with the research by Dunham (1977) regarding practice

order, and suggested that practicing a skill on one side to a

certain criterion level (sequential) is more effective than

switching back and forth from side to side during skill

acquisition (serial). Where this research confuses the issue

is deciding on which side of the body to start skill

acquisition, preferred or non-preferred.

This information directly contradicts findings from

Byrd, Gibson, & Gleason (1986), in which 96 female subjects

ranging in age from 7 to 17 years employed a novel rotary

pursuit tracking task. This study will be discussed further,

but the results showed that the subjects had greater transfer

of information going from the preferred limb to the non-

preferred limb in their initial practice order.

14

Finally, it is apparent from the research that age also

plays a roll in the influencing bilateral transfer. Getting

back to Byrd, Gibson, & Gleason (1986), a novel rotary

pursuit tracking task was used, and measured bilateral

transfer in 96 female subjects ranging in age from 7 to 17

years. In this study, a novel task was used to minimize

transfer from past situations, and to limit the complications-

by uncontrolled factors. It was expected that the ability to

transfer more information may be functions of maturation or

the accompanying of a greater variety of neuromuscular and

psychological/cognitive experiences.

This study suggested that there was definite progress in

skill acquisition between the ages of 7 to 13 years, but the

15 to 17 year old group learned the skill significantly

faster. Two explanations for increased learning in the older

subjects were suggested. First, their increased repertoire

of stored motor experiences, and second, their improved

ability to analyze motor problems. The authors suggest that

these possible explanations may facilitate adaptation to new

situations. It is not clear at what age bilateral transfer

is maximized, but the results of this study suggest it is not

before the age of 17 in females.

When instructing individuals in complex movement

patterns, like improving on the instep drive, a study by

Southard & Higgins (1987) researched the effects of practice

versus demonstration on the development of a movement pattern

15

for a motor skill. Forty females ranging in age from 18-28,

that had no previous racquetball experience, participated in

the study. The authors suggested that during skill

acquisition of hitting a forehand shot in racquetball, the

beginner's primary goal will be to make contact with the ball

only. During skill acquisition of a complex motor skill like

hitting a forehand, individuals will employ an inefficient

movement pattern to attain the goal of making contact.

The results suggested that the control and demonstration

groups showed the same amount of improvement in their

movement patterns. The practice group, however, made

significant improvement in their movement patterns. The

subjects were not given any augmented feedback during

acquisition, but the intrinsic visual feedback from actual

performance was available to the practice group only. It was

suggested that the actual practice of the skill provided the

learner with the kinematic characteristics of the skill, and

enabled the learner to improve their movement pattern more

rapidly than the demonstration only group.

Southard & Higgins provided their subjects only 10

minutes of practice for 5 consecutive days. This study

suggested that 5 practice sessions was enough time for

beginners to show a significant improvement in a movement

pattern.

Southard (1989) provides further research on changes in

striking patterns. In this study, the changes in an arm

16

striking pattern as a result of practice was measured, also,

what effect speed and accuracy have on the changes of the

movement pattern.

The subjects were hitting a ball off of a batting tee.

Ten females between the age of 18 and 26 participated in the

study. They were broken into three practice groups. Group 1

was instructed to hit the ball with maximum velocity without

regard to accuracy, Group 2 was instructed to hit the ball as

accurately as possible, and Group 3 was instructed to hit the

ball as fast with the greatest amount of accuracy possible.

They were not shown how to hit the ball. Again, they relied

on the feedback from their performance, to aid them in their

improvement.

The subjects initially constrained limb segments, or

used an inefficient striking pattern, because it is easier to

control the segments of the striking limb if they are to act

as a unit. Since the main goal was to make contact with the

ball, again, their striking pattern was hindered. With

practice, all subjects' striking patterns became less

constricted and more efficient.

With regards to the striking instructions, it was found

that sacrificing velocity to increase accuracy was not the

best strategy. First, a reduction in velocity slows

development of the striking pattern, and increasing accuracy

may not be achieved by slowing down the striking pattern.

17

Also, if inefficient movements are learned, they become

potentially difficult to unlearn in the future.

In testing theories like bilateral transfer of the

instep drive, assessment of velocity and accuracy will be

necessary in determining ability levels, and development of

that ability after treatments.

In a study developed by Cohen et al. (1994), the tennis

serve of 40 tournament-level tennis players was evaluated.

The study was interested in determining the relationship

between anthropometric data, extremity strength, and

functional serve velocity. The measurement in ball velocity

was in miles per hour, and the equipment used to measure

velocity was a calibrated Juggs radar gun (Tribar Co.,

Montreal, Canada). The radar gun was placed in one standard

location at the opposite end or the baseline of the receiving

end of the court. Another experiment by Pawlowski and Perrin

(1989) studied throwing velocity in intercollegiate pitchers.

The assessment tool used in their study was an M.P.H. K-15

(Chanute, Kansas) hand held stationary radar device.

Velocity was also measured in. miles per hour, and the hand

held stationary radar device was mounted on a tripod. It was

calibrated before each pitch, following the instructions

given in the operating instructions (R & R Electronics,

Hammonton, NJ). For right handed subjects, the device was

placed to the right of the throwing platform, and to the left

for left handed subjects.

18

In a study developed by Fleury and Bard (1985), the

variation in response to diverse coincidence/anticipation

tasks in subjects aged 9-52 years of age was studied. They

hypothesized that aging has a profound implication for many

aspects of both motor and perceptual individual behaviors.

186 subjects volunteered for this study, and they were broken

up into 6 different age groups. (9-11, 11-14, 14-18, 18-30,

30-41, 41-52)

A throwing accuracy test was given, and a target was

utilized. The target was a 50cm x 50cm frame inside which

the subject must throw a ball. Photoelectric cells located

on horizontal and vertical axes on the frame provided the

precise location of the ball's impact. The subjects facing

the target were 3m away, and were allowed 10 throws. The

accuracy of the attempts were measured on the X and Y axes,

and converted to a 1 to 9 score. The score of 1 represented

the best throw, and was the center of the target. The target

was broken up into concentric zones each of which was 3cm

wide.

A study presented by Gruetter and Davis (1995),

investigated the differences between oversized tennis

racquets and standard sized racquets. Tests for accuracy on

four basic strokes were measured. 57 undergraduate students

were the subjects, and they were separated into two groups,

intermediate (n=29) and beginners (n=28). A skill test was

constructed, by painting lines on the tennis court, and the

19

score of each shot related to the area that the ball bounced

in on the opposite side of the net. Each subject attempted

10 shots, 5 down the line and 5 cross court for both the

forehand and the backhand. It would appear that the

researchers were most interested in mean scores for the two

different groups.

An extensive computer/electronic search for information

regarding soccer skills and accuracy has been completed. The

inability to locate specific information on vital aspects of

this study has made it necessary to conduct a pilot study.

Some specific information missing from the literature review

include: specific placement of the radar detection device,

distance between point of kick to target, value to be

attached to separate target areas, and scoring apparatus.

Purpose

This study examined two practice orders and their effect

on the bilateral skill of the instep drive in soccer. The

two practice orders were: sequential practice order and

serial practice order. The purpose of this study was to

determine if one practice method was superior to the other in

teaching children the instep drive, and to provide soccer

coaches with the information on how they can most effectively

spend their practice time with this bilateral skill.

20

Operational Definitions

Preferred Foot: the foot the subject prefer to use when

asked to kick a ball as fast and as far as possible. This

foot will be used first during all practice and testing

phases.

Organized Soccer Experience: describes the number of

years involved in an organized league, with coaches, and

standings recorded.

Other Sports Teams: describes the teams that are

organized in leagues, with coaches, and standings recorded.

Instep Drive: a style of kicking a ball with the instep

or the top of the foot. It was described to the subjects as

the top of their foot, or where their shoe laces cover their

feet.

Things Done When Playing: are the things done while

actively playing. (ball games, bicycle riding, skating,

running/jumping/swinging, etc.)

Things Done When Not Playing: less physical activities.

(reading, cooking, socializing, watching TV, sleeping,

working/playing on computers, etc.)

Assumptions

One assumption is that the subjects will be giving their

best efforts during the practice sessions and testing

periods.

21

Another assumption will be that the subjects are honest

and truthful when responding to the questionnaire regarding

their organized soccer experiences.

A third assumption is that this test is sensitive enough

to produce a measurable difference in the subjects' skills.

An important assumption is that the students will be

able to produce a proper instep drive prior to practice.

Hypothesis

The sequential order of practice is more effective than

the serial order of practice for skill acquisition in the

bilateral skill of the instep drive in kicking a soccer ball.

Limitations

One limitation is the number of subjects tested as time

and resources were limited.

Another limitation is the number of instructors during

the practice phase. There were a number of students

practicing at once, and the instructor was able to watch 1 or

2 children at a time. That means a number of subjects

practiced without the aide of personal instruction.

Another limitation was locating radar equipment that is

sensitive enough to measure all speeds of the subjects

attempts.

22

Delimitations

The study was limited to individuals with less than five

years of organized soccer playing experience, and

demonstrated a low level of skill for the instep drive. It

was thought that this provided for a significant and

measurable improvement in the subject's skill performance

after treatment.

The testing for accuracy and velocity was held indoors

to control for variables like wind, temperature, and to

minimize potential distractions for the subjects.

Significance of the Study

Soccer is the most popular game in the world, and there

are millions of children playing on organized teams. Coaches

and players train very hard at improving their skills. There

are a number of skills that must be performed from both sides

of the body. These are called bilateral skills. The instep

drive is a style of kicking a ball, and it has many uses in

soccer including: shooting, crossing, clearing defensively,

and making longer types of passes. The ability to use both

legs is critical, especially at the higher levels of the

game. Unfortunately, coaches and their soccer teams have

limited practice time. This study provided information on a

practice method related to the transfer of bilateral skill of

the instep drive.

Chapter Two

Methodology

Subiects. The subjects were 5th grade elementary school

children from a local elementary school in northern

California. There were 23 boys and 22 girls who completed

all requirements of the study, and their ages ranged from 10

to 11 years.

Fifth grade students were chosen, because it was

expected that they would demonstrate a lower level of skill,

for the instep drive, than older children. Both males and

females were studied in this experiment, and their

differences are noted in the results and discussion sections.

The subjects for the experiment were taken from two

separate classes from the elementary school, and the

intervention was scheduled as part of their regular classroom

day. All students who completed the questionnaire and agreed

to participate, were included in the activity. However, only

the data of those subjects who completed all portions of the

experiment was computed. To avoid any mixing of information

between practice method groups, one class was directed to

employ the serial practice method during the treatment

portion of the experiment, while the other class employed the

sequential practice method. The determination of which class

would employ which practice method was chosen at random.

23

24

The study was a pre-post test design, and was set up as

follows:

Grp 1 01 T1 02

Grp 2 03 T2 04

Because this study was designed to determine the effects of

practice methods on bilateral transfer, T1 and T2 represent

the two different practice methods which were administered.

Independent measured t-tests were conducted to test for

significant group mean difference between pre and post

treatment. The changes between 01 and 02, and between 03 and

04 were the most critical changes to analyze for this study.

The parents of the students were sent a letter which

represented an implied consent form (Appendix A). The letter

described the purpose of the study as well as the experiment

that their children were to participate in. In the letter,

they were instructed to contact the school or the

experimenter if they did not wish their children to

participate in the study.

Students read and signed the consent form (Appendix A)

in the presence of their teacher and the experimenter, and

then the students completed the questionnaire (Appendix B),

which included information about organized soccer experience,

play time activities, other interests and activities when not

playing, as well as general information about soccer

experiences like attending games and watching soccer games on

TV.

25

In addition, each student was asked to indicate their

preferred limb. This piece of information is important

because the subjects were instructed to begin each practice

session and testing phase with their preferred limb.

Testing phase. The instruction and protocol for the pre

and post-test were identical.

Pre and post-test consisted of each subject performing

the instep drive of a soccer ball with both feet. The

dependent variables of velocity and accuracy were measured.

The pre and post-tests consisted of 20 attempts, 10 with

the preferred limb, and 10 with the non-preferred limb. The

scores for velocity and accuracy were noted on score sheets

(Appendix C). The subjects were instructed to use their

instep, to drive the ball at the target wall, and produce as

much velocity as possible.

Since maximal effort was measured in the pre and post-

test phases, the subjects were encouraged and instructed on

how to warm up the kicking mechanisms before the experiment

begins. During the testing phases only, the subjects were

given the opportunity to kick a ball at a wall while warming

up. The subjects who opted to take practice attempts for the

pre and post-tests, were limited to five attempts for each

foot. During these optional warm up attempts, the subjects

were not given velocity feedback, nor were they able to kick

at the assessment target. The subjects began the testing no

more than three minutes after completing warm-ups.

26

For both test phases, the subjects were instructed to

produce the attempts in the practice order they were

employing during the treatment phase. For example, the group

who employed the sequential practice method during the

treatment phase produced all ten attempts from their

preferred foot before using their non-preferred foot.

Likewise, the group employing the serial practice method

alternated from preferred foot to non-preferred foot for all

20 attempts.

Since maximal effort was requested from the subjects,

they took a minimum of 15 seconds between attempts. Since

time was an issue in the testing phase, the subjects were

given a maximum of 60 seconds between attempts.

In assessing velocity, all attempts that produce a

reading from the radar device were noted and figured in for

average velocity. Any attempt that did not produce a reading

from the radar device, but hit the target wall on the fly was

counted for accuracy, but was not measured for average

velocity.

When assessing accuracy, any ball that was kicked, but

did not reach the wall before bouncing was given a score of

zero. Any ball that was kicked, reached the wall before

bouncing, but was not within any target areas was given a

score of one and averaged for mean accuracy.

27

Treatment Phase. After the pre-test was completed, the

subjects participated in five practice sessions. The

practice sessions were given only one per day, and were

scheduled to begin on a Monday and end the following Friday.

Because of scheduling problems and pre-testing that took

longer than expected, the schedule was modified. The

treatment phase began on Monday and Tuesday, continuted on

Thursday and Friday, and ended on the following Monday. The

subjects were given instructions and a brief demonstration at

the beginning of each of the five practice sessions. The

instructions were provided to break down different elements

of the instep drive, and describe one or more component for

the subjects to work on during each practice session. Both

groups were given identical instructions and demonstrations.

The different elements and days provided to the subjects are

listed in (Appendix D).

The testing and practice sessions were completed indoors

in the school gymnasium, and targets were attached to the

walls for the subjects to have a frame of reference to work

from. The subjects did receive minimal augmented feed back

during the practice sessions, and they were encouraged to use

the environmental feedback available to them from their

practice performances.

Before beginning the experiment, the subjects were given

instruction on how to warm up the kicking mechanisms. For

each practice session, the subjects were given ample

28

opportunity and encouraged to warm up, but they were not

given an opportunity to kick a ball before the practice

attempts begin. There were a number of reasons for this.

First, since this was an indoor experiment, the potential for

injury and or property damage was present, and second, there

was the potential loss of some control by the experimenter.

Each practice session consisted of 30 total performances -

of the instep drive for each subject. The subjects were

instructed to take exactly 15 attempts with their right foot

and 15 attempts with their left foot. Again, one group was

using the sequential practice method (RRRRR,LLLLL), while the

other group employed the serial practice method (RLRLRLRLRL).

Following the five practice sessions, the post-test was

completed, which was identical in instruction and protocol to

the pre-test.

Also, in future experiments using this methodology, a

follow-up test some time after the post-test could be

considered. This second post-test could be used to measure

the issue of retention, but will not be a part of this

experiment.

Assessment. The testing for accuracy and velocity were

held indoors to control for weather effects, and to minimize

potential distractions for the subjects.

The tests consisted of 20 attempts, 10 with the

preferred foot, and 10 with the non-preferred foot. The

29

subjects were instructed to use their instep, to drive the

ball at the target wall, and produce as much velocity as

possible.

To measure velocity, a radar detection device was used.

The device was The JUGS Radar Gun (The JUGS Company, 1997),

and this piece of equipment is heavily used in baseball and

softball to measure pitching velocity. The JUGS Radar Gun

measured the speed of the ball in miles per hour (mph). The

gun was hand held by the score keeper. She was seated in a

chair, approximately 2 feet to the right of the target, with

her back up against the target wall.

The distance between the point of the kick to the

wall/target was 10 yards or 30 feet. The space available in

the gym was limited, and the maximum distance the subjects

had to approach the ball was 12 ft. See Figure 1. for a

schematic drawing of the study's floor plan.

The system for measuring accuracy was extremely simple.

Tape was applied to a tarpaulin, and then hung on the wall in

the gymnasium used for testing. Three different sized

concentric squares were formed. The inner-most square was

assigned a score of 10 and was 3 ft x 3 ft in size. The

middle square was given a score of 7 and was 6 ft x 6 ft in

size. Finally, the outer-most square will be given a score

of 5 and was 9 ft x 9 ft in size. All attempts that hit the

target wall, on the fly, but did not hit within any of the

30

target squares was given a score of 1. See Figure 2. for an

illustration of the target assessment portion of the study.

Each subject's score was recorded on a score sheet

(Appendix C) immediately following each attempt. There were

4 different score sheets produced. This was done to make

sure the score keeper could keep track of which foot the

subject was to begin with, and which foot was to be used for

each attempt.

Figure 1. Schematic drawing of the floor plan for the

assessment portion of the study.

31

Figure 2. Frontal view of the target with corresponding

dimensions of the concentric squares.

Pilot Study

An extensive computer/electronic search for information

regarding soccer skills and accuracy was completed. The

inability to locate specific information on vital assessment

aspects of this study made it necessary to conduct a pilot

study before the actual study began.

The pilot study was conducted to determine the

following: specific placement of the radar detection device,

distance between point of kick to target wall, value to be

attached to separate target areas, and size of the target

areas. The subjects for the pilot study were three female

32

college soccer players and one male college soccer player.

The last subject was a 5th grade student who was only

available for one night. Since the 5th grader was available

for such a short time, he was used to make sure 5th graders

could hit the target wall on the fly. He completed one test

phase. His technique and abilities provided enough evidence

to go forward with the experiment as it was designed. The

pilot study, which was completed prior to the beginning of

the experiment, did not suggest any changes to be made in any

of the areas of question discussed above.

Statistical Analysis

The research design was a pre-test, post-test design

with two experimental groups measured on two variables. The

dependent variables measured were velocity in miles per hour

(mph) and accuracy based on a point system. The higher the

amount of points achieved, the greater the accuracy. The

independent variable was practice order. Measures on each

variable were obtained during the pre-test and post-test for

each participant.

The pre-test and post-test differences were determined

for both groups, and an independent sample t-test was

employed to analyze the data, using SPSS for Windows Student

Version 6.1 (SPSS, Inc. 1996). The criterion for statistical

significance was set at the .05 alpha level.

Chapter Three

Results

The study was a pre-test, post-test design. Two

variables, velocity and accuracy, were measured to determine

the effects of practice order in teaching children the

bilateral skill of the instep drive in soccer. Accuracy and

velocity were measured prior to and following both the serial

and sequential practice order.

Participants in the study were fifth grade elementary

school students from two separate classrooms. Only the

scores from those students who completed all elements of the

study were computed.

It was important to keep the two practice orders

separate and independent of each other. Thus, one class was

instructed to employ the serial practice order, while the

other utilized the sequential practice order during all

phases of the study. Further, the two groups practiced

separately and were tested at different times.

To determine if there was a significant difference

between the two practice orders in the velocity and accuracy

of kicking a soccer ball, a t-test for the equality of means

was computed for both variables using the pretest scores. T-

test results confirmed no significant difference between the

two groups for either accuracy (M = 1.63, SD) = 1.36) versus

33

34

(M = 1.56, SD = 1.35), p = .861, or velocity (M = 23.50, SD =

4.65) versus (M = 24.44, SD = 4.39), p = .836, for the

sequential and serial groups respectively.

Unfortunately, after the treatment phase of the study,

the post-test scores showed a decrease for both practice

order groups and for both of the variables, accuracy and

velocity. The post-test scores for the sequential group are

as follows: accuracy (M = 1.20, SD = 1.49), and velocity

(M = 19.81, SD = 6.41). The post-test scores for the serial

group are as follows: accuracy (M = 1.34, SD = 1.37), and

velocity (M = 22.47, SD = 5.65). These results will be

discussed further in the discussion section of the following

chapter, but the results are presented below (Table 1).

Table 1

Mean Accuracy and Velocity Scores

at Pre-Test and Post-Test

Variable Pretest Posttest M

SD M SD

Accuracy

sequential 1.63 serial 1.56

1.36 1.35

1.20 1.34

1.49 1.37

Velocity

sequential 23.50 serial 24.44

4.65 4.39

19.81 22.47

6.41 5.65

35

The questionnaire provided a demographic information

regarding the participants in the study (Table 2).

Table 2

Demographics of Participants

Variable Sequential (n = 24)

Serial (n = 21)

Gender

Girls

Boys

11 (46%)

13 (54%)

11 (52%)

10 (48%)

Years of Age

10

11

17 (71%)

7 (29%)

18 (86%)

3 (14%)

Ethnicity

Caucasian

Native American

Hispanic

Other

19 (79%)

1 (04%)

3 (13%)

1 (04%)

17 (81%)

3 (14%)

1 (05%)

0 (00%)

Years of Organized Soccer Experience

0.0

1.0

2.0

3.0

4.0

5.0

16 (67%)

1 (04%)

4 (17%)

1 (04%)

1 (04%)

1 (04%)

16 (76%)

3 (14%)

0 (00%)

1 (05%)

1 (05%)

0 (00%)

36

When comparing the two classes, one finding should be

mentioned. An independent t-test was calculated to see if

the two classes were similar in their organized soccer

experience. The results were recorded in years of organized

soccer experience, and presented in (Table 3). The

sequential practice group indicated less than 1 year of

experience (M = .88, SD = 1.45), while the serial practice

group indicated slightly less than half a year (M = .48, SD =

1.08). These results were not significant (p =.075).

Table 3

Number of Years on Oraanized Soccer Team

Variable Number of Cases

Mean Standard Deviation

Sequential

Serial

24

21

.88

.48

1.45

1.08

37

Of the 50 students in the two 5th grade classrooms, 45

(90%) completed all phases of the study. Of the 45 who

completed all phases, 23 (51%) were boys and 22 (49%) were

girls. The ages of the participants ranged from 10 years

(78%) and 11 years (22%). In addition, most of the students

listed their ethnicity as Caucasian (80%), while (9%) are

Native American, (9%) Hispanic, and (2%) responded as being

other.

Generally speaking, the participants had little or no

organized soccer experience, with 32 (71%) reporting no

organized soccer experience, 4 (9%) with 1 year, and 9 (20%)

with more than 1 year. This represents a group lacking in

soccer experience with 80% having little or no organized

soccer team experience.

Further, soccer is not a sport that is generally watched

on TV or attended by the participants in this study. Thirty-

one (69%) of the participants responded that they have never

seen a soccer game on TV, and only 5 (11%) of them have seen

more than 6 games on TV. When asked if they have ever been

to a college or professional soccer game, 40 (89%) responded

that they had not. Of the remaining 5 participants, 4 (9%)

have not attended more than 3 games.

The majority of this group of participants does,

however, participate on other organized sports teams. When

asked about their organized sports team experiences, the

participants first 2 responses were recorded. Only 16 (36%)

38

of the participants have never participated in organized

sports at all, while 16 (32%) of the participants participate

on at least 2 organized sports teams.

The major sports of basketball, baseball and football

are heavily represented. Organized basketball, for example,

has 18 (40%) of the participants actively participating,

while 17 (38%) of the participants play organized baseball.

Of the 23 boys in the study, 9 (40%) of them have played

organized football. It is not surprising that these major

sports are also viewed on TV and attended at a much greater

rate than soccer.

The participants were also asked about their free time

while not at play (non kinetic), and their play time or

unorganized activities (kinetic). Again, their first 2

responses were recorded.

During their free time, while not at play, the two

activities that are significantly higher than all others are

reading and video type activities such as watching TV,

working on computers, or playing video games. Seventeen

(49%) of the participants responded that they regularly watch

TV, work or play on their computers, and play video type

games. The second response, reading, showed that 16 (36%) of

the participants regularly engage in this activity.

During play time or unorganized activities, games that

included some kind of ball are heavily engaged. These ball

type games include basketball, baseball, football, soccer,

39

volleyball, and tether ball. Again, the first two responses

were recorded and, 30 (67%) of the participants put some kind

of ball game as their first response, while another 16 (36%)

included this as their second response. There were no other

responses to unorganized activities that appear to be of

importance.

Correlation coefficients were computed to explore

relationships between a number of variables. Regarding

gender, (Table 4), boys recorded higher scores than girls in

the testing phases in both dependent variables, pre-test

accuracy (r = -.46, n = 45, p < .002), pre-test velocity

(r = -.37, n = 45, p < .013), post-test accuracy (r = -.41,

n = 45, p < .005), and post-test velocity (r = -.49, n = 45,

p < .001).

Table 4

Correlation Coefficients Between Gender and the Dependent Variables Accuracy and Velocity in all Participants

Variable Coefficient (r) N P

Pretest Accuracy -.46* 45 .002

Pretest Velocity -.37* 45 .013

Post Accuracy -.41* 45 .005

Post Velocity -.49* 45 .001

40

An important correlation exists between velocity and

accuracy (Table 5). The importance of this correlation will

be discussed further in the following chapter. There was a

positive correlation between pretest velocity and pre-test

accuracy (r = .71, n = 45, p < .001), and post-test velocity

and post-test accuracy (r = .66, n = 45, p < .001). Thus,

the subjects who produced higher velocity also scored higher

in accuracy.

One other correlation of note occurred. Those subjects

with high scores in the pre-test phase also had high scores

in the post-test phase. Therefore, there was a positive

correlation between pre-test accuracy to post-test accuracy

(r = .68, n = 45, p < .001), and pre-test velocity to post-

test velocity (r = .77, n = 45, p < .001).

Table 5

Correlation Coefficients Between Velocity and Accuracy

Variable Coefficient N

Pretest Velocity to Accuracy

Posttest Velocity to Accuracy

.71*

.66*

45

45

* p < .001

Chapter Four

Discussion

The theory of bilateral transfer is an important one,

and deserves a great deal more attention by researchers.

Briefly, it suggests that when one limb is performing a

skill, the other limbs of the body are actually learning to

perform the same skill. There is a great deal of research

that would suggest that the theory is valid. However, there

are differing theories as to how this learning is

accomplished. The two main dissenting theories are the

neuromuscular activation theory and the cognitive theory.

This theory is important because of its application to

skill learning in the sports world. Two bilateral skills

outside the sports world are typing and playing the drums.

Some bilateral skills in sports include: dribbling a

basketball, rolling a kayak, throwing a frisbee in ultimate,

and kicking a ball in soccer. Each of these skills are

important for greater proficiency, with both sides of the

body, at the highest competitive levels.

It is the sport application to this theory that provided

the interest in completing the current study. One problem

facing coaches in youth sports is the limitation of practice

time. The purpose of this study was to determine if a

practice order could better utilize soccer coach's time

teaching their players in the bilateral skill of kicking a

soccer ball.

41

42

From the literature reviewed, it was expected that the

sequential order would be more effective than the serial

order of practice in learning to kick a soccer ball.

Further, it was expected that 5 days of practice would be

sufficient time to see a change in the kicking abilities of

the subjects. Finally, the system of assessing accuracy and

velocity appeared sound, as the literature review produced

other studies that were successful in using JUGS machines for

measuring velocity, and similar target systems for measuring

accuracy.

It was hoped that this study would provide answers to a

number of questions that are relevant to the bilateral skill

of kicking a soccer ball. Obviously, the issue of which

practice order would effect kicking skill was the main topic,

but there were some other interesting questions raised. For

example, which foot should one start with (preferred or non-

preferred), or was 5 days of practice long enough to show

improvement of a skill as complex as the instep drive in

soccer?

Most importantly, there is the question of whether or

not information would transfer to the non-kicking leg. The

study by Hicks, Frank, and Kinsbourne (1982) suggested that

transfer of information to the non-practicing limb is blocked

if it is involved in an unrelated task. Is the non-kicking

leg involved as a related task and therefore able to receive

transfer of information, or is the non-kicking leg involved

43

in a unrelated task and would therefore have difficulty

receiving the transfer of information? The answer to this

question alone could impact many other complex sport skills

where multiple limbs are involved in tasks of their own.

Unfortunately, the study did not prove the hypothesis

that suggested that the sequential practice order was

superior to the serial practice order in the transfer of

information in kicking a soccer ball. Further, the questions

listed above about bilateral transfer will be left unanswered

for now.

In a comparison of groups, it is important that the two

groups start out relatively even. The problems did not occur

as the result of differences between the groups. The scores

from the pretest were tabulated, and showed that there was no

significant difference between the two groups in their

kicking ability. Pre-test scores for accuracy were (M =

1.63, SD = 1.36) versus (M = 1.56, SD = 1.35), p =.861, and

pre-test scores for velocity were (M = 23.50, SD= 4.65)

versus (M = 24.44, SD = 4.39), p = .836 for the two groups.

A number of problems with the methodology in this study

became apparent during the pre-test phase of the experiment.

First, the established scoring system for accuracy did not

consider kicking strength of the subjects. A number of

subjects had difficulty producing enough power and lift on

the ball, to hit the target wall on the fly. To determine

accuracy, the ball had to reach the wall on the fly, to

44

achieve a score greater than zero. A number of students

kicked the ball down the middle of the target, but on the

ground, and thus were given a score of zero for accuracy,

while other students were reaching the wall on the fly, but

were wide of the target, resulting in a score of 1 for that

attempt on accuracy.

The results support this observation. That is, the

correlation between velocity and accuracy, suggests that

there is a design flaw, because the higher the score for

velocity, the higher the score for accuracy. It takes a

certain amount of velocity to have the ball reach the target

wall in the air. The subjects who did not possess the

ability to produce this velocity would obviously have little,

if any, chance of scoring above a zero for accuracy. These

subjects may have kicked the ball down the middle of the

target, but did not accrue accuracy scores because of their

lack of kicking strength.

The lack of kicking strength may also explain the

difference in scoring between the boys and girls. In this

study, boys generally scored higher in both accuracy and

velocity than girls. This further suggests a change in the

scoring is needed. Some boys and girls had difficulty

producing enough velocity to reach the wall in the air, but

during the testing, it appeared that more girls had this

problem. Again, this would effect their accuracy scores.

45

So, the problem in scoring is an inequality given to the

two different components of accuracy for this particular

study. The two components of accuracy are horizontal and

vertical. Kick attempts with a vertical component, or

reaching the wall on the fly but not on target, were accruing

higher scores than those kick attempts with a horizontal

component, or reaching the wall within the frame of the

target but on the ground.

The second methodology problem, also observed during the

pre-test phase, was that the results between the pre and post

tests would not be a fair comparison. Originally, the study

called for subjects that would be able to kick the ball with

their instep, but their skill level should be that of a

beginner. The reason for this was to have subjects who could

show a significant development in the instep drive in a short

amount of time.

The subjects in the study were introduced to the topic,

and they were advised that the study was to measure kicking

ability with the instep. They were given a brief

demonstration of the skill and testing began. It was

observed, although not measured empirically, that a majority

of the subjects, above 90%, were kicking the ball with their

toes and not their instep. Kicking the ball with the toe

enables the performer to produce power, but accuracy is very

difficult to achieve, especially in game type situations with

a moving ball.

46

What makes the results of the testing an unfair

comparison is that the techniques employed by the subjects in

the two tests were very different. The differences between

the two techniques are significant, such as the angle of

approach. When kicking with the toe, the subjects approached

the ball in a straight line to the target, while kicking with

the instep requires an angled approach to the ball. Other

differences include the placement of the plant foot and

locking the kicking foot ankle with the toe pointing down and

away from the body.

During the treatment phase of the study, the subjects

were taught the proper technique in kicking with the instep,

and they only had five opportunities to practice this new

technique. During the post-test phase, some of the subjects

reverted back to using their toe, but many of the subjects

were employing the proper technique and used their instep.

To avoid these potential problems in the future, there

are two methodology suggestions to consider. First, accuracy

points should be accrued for those subjects who are not able

to reach the wall on the fly. Any attempt that hits the

ground before reaching the target wall, but hits the wall

within the frame of the target should be given points for

accuracy. The points given for the vertical component should

be equal to the points given for the horizontal component.

In other words, a score of one should be given to those

attempts that hit the wall within the target, but not on the

47

fly, and a score of one should be given to those attempts

that hit the wall on the fly outside the frame of the target.

Second, the subjects chosen for a study like this in the

future should have some basic soccer skills and education.

The technique employed by the subjects in the pre and post-

test phase must be the same. The treatment phase should be

used to improve the technique of the subjects and not to give

them a completely different technique. The purpose of this

study was to determine if there was a difference in practice

methods employed. If the techniques are not the same between

tests, the results can not be considered a fair comparison.

One instrumentation problem was uncovered during the

post-test phase. The recorder noticed that there were a

number of attempts that did not register on the JUGS radar

gun. She then noticed that there were no velocity scores

under 20 mph. It turns out that the JUGS radar gun used,

even though it had a low speed setting, does not record

velocities under 20 mph.

When the results for velocity were calculated, only

those attempts that produced a reading were used in the

calculation. This would suggest that a number of the average

velocities by the subjects were actually lower than they have

been reported.

Finally, on a more positive note, although this study

was unable to provide an answer to our hypothesis, the

subjects have been presented with information on how to

48

become better soccer players. Kicking a stationary ball is

not a situation that occurs often in soccer, and kicking a

moving ball with power and accuracy with the toe is

exceptionally difficult. The study has provided the subjects

with the basics in kicking with the instep, which is used in

many different situations during a soccer game. The teachers

of the classrooms used have both personally commented on the

childrens' enjoyment of their soccer sections in physical

education. It would appear that their soccer skills have

improved, and their enjoyment of the game have improved along

with it.

References

Byrd, R., Gibson, M., & Gleason, M. H. (1986). Bilateral transfer across ages 7 to 17 years. Perceptual and Motor Skills, 62, 87-90.

Cohen, D, Mont, M., Campbell, K., Vogelstein, B., & Loewy, J. (1994). Upper extremity physical factors affecting tennis serve velocity. The American Journal of Sports Medicine. 22, 746-750.

Dunham, P. (1977). Effect of bilateral transfer on coincidence/anticipation performance. Research Quarterly for Exercise and Sport. 48, 51-55.

Dunham, P. (1977). Effect of practice order on the efficiency of bilateral skill acquisition. Research Quarterly for Exercise and Sport, 48, 284-287.

Dunham, P. (1978). Retention of bilateral performance as a function of practice order. Perceptual and Motor Skills, 46, 43-46.

Fischman, M., & Sanders, R. (1991). An empirical note on the bilateral use of a baseball glove by skilled catchers. Perceptual and Motor Skills, 72, 219-223.

Fleury, M., & Bard, C. (1985). Age, stimulus velocity and task complexity as determiners of coincident timing behavior. Journal of Human Movement Studies, 11, 305-317.

Gruetter, D., & Davis, T. (1985). Oversized vs. standard racquets: Does it really make a difference? Research Quarterly for Exercise and Sport, 56, 31-36.

Hicks, R. E., Frank, J. M., & Kinsbourne, M. (1982). The locus of bimanual skill transfer. The Journal of General Psychology, 107, 277-281.

Parker-Taillon, D., & Kerr, R. (1989). Manual asymmetries within the performance of a complex motor task. Human Movement Science, 8, 33-44.

Pawlowski, D., & Perrin, D. (1989). Relationship between shoulder and elbow isokinetic peak torque, torque acceleration energy, average power, and total work and throwing velocity in intercollegiate pitchers. Athletic Training, 24, 129-130, 132.

49

50

Puretz, S. L. (1983). Bilateral transfer: The effects of practice on the transfer of complex dance movement patterns. Research Ouarterlv for Exercise and Sport, 54, 48-54.

Smith, P., & Davies, M., (1995). Applying contextual interference to the pawlata roll. Journal of Sports Sciences, 13, 455-462.

Southard, D., & Higgins, T. (1987). Changing movement patterns: Effects of demonstration and practice. Research Quarterly for Exercise and Sport, 58, 77-80.

Southard, D., (1989). Changes in limb striking pattern: Effects of speed and accuracy. Research Quarterly for Exercise and Sport, 60, 4, 348-356.

SPSS for Windows Student Version 6.1 [Computer software]. (1996). SPSS, Inc.

The JUGS Radar Gun. (1997). The JUGS Company.

APPENDIX A

Consent Forms

51

52 Parental

Bilateral Transfer Research Project

Dear Parent,

This letter is to inform you that the faculty and staff

at Fortuna Elementary School have agreed to participate in a

research project on using the instep drive to kick a soccer

ball. Your child's class has been chosen for this study.

This research project will study the effect that

practice order has on the skill development of the instep

drive in soccer. The purpose of the study is to determine

whether one practice method is superior to another in

developing beginning soccer players' instep drive skill on

both feet. The duration of the study will be twelve calendar

days, however, your child will participate only seven days

during that time. Their participation will be scheduled

during their regular physical education period at school.

There will be a pretest on the first day to measure your

children's kicking ability. Days two through six will

consist of instruction, demonstration, and practice attempts

of the instep drive. On the final day of the project, we

will conduct a posttest to determine the development of the

children's' progress.

If you do not wish your child to participate, please let

us know by contacting the school or your teacher directly.

Sincerely, Paul A. Stumpf Graduate Student Kinesiology Humboldt State University

53 Child

Bilateral Transfer Research Project Informed Consent

This research project will study the effect that

practice order has on the skill development for the bilateral

skill of the instep drive in soccer. The purpose of the

study is to determine whether the serial practice method is

superior to the sequential practice method in developing

beginning soccer players' instep drive skill. The duration

of the study will be twelve calendar days, however, you will

participate only seven times during that time. Your

participation will be scheduled during your physical

education period at school. There will be a pretest on the

first day. Days two through six will consist of instruction,

demonstration, and practice attempts of the instep drive. On

the final day of the project, we will conduct a posttest to

determine your progress.

Risks

There is a slight risk of injury to the kicking leg, as

you will be asked for maximal effort of velocity while

kicking the ball. You will be properly warmed up by an

evaluator before participation begins for each session.

54 Benefits

The benefits of this project could be significant for

all youth soccer participants in this area and beyond. If

the program produces the intended findings, then the results

of this project will be submitted for publication. If this

is to occur, you will be contributing greatly to the

understanding of how to productively use practice time for

youth soccer coaches. This research may produce incentive

for more research to determine the best way to coach children

for other sports as well.

Confidentiality

The pre and post tests will be conducted in the familiar

surroundings of the school's indoor basketball court. All

data will be coded with a number to maintain confidentiality.

Your name will not be known to the researchers who analyze

the data, nor be presented in any publications of the results

of the project.

Safety Measures

The staff who will administer the tests will be trained

for both safety and reliability. The testing and treatment

phases will occur on your school grounds, so you will not be

permitted to leave the grounds for any reason.

55 Contacts

If you have any questions about your participation in

this research, please feel free to ask any of the researchers

or staff conducting the testing or training. You may also

call Paul Stumpf at Humboldt State University at

826-4532. If you have questions about your rights as a

research subject, you may ask any of the researchers, or

contact the Office for Research and Graduate Studies at

Humboldt State University 826-3949.

Voluntary Participation

Your participation in this research project is

completely voluntary. You may withdraw at any time without

question.

Bilateral Transfer Research Project

Informed Consent

Child's Consent:

Your signature below indicates that you agree to

participate in the project to determine the effect practice

order has on bilateral transfer of the instep drive in

soccer. It also indicates that you realize that these

procedures are part of a research project that will be

conducted over seven days, and the results may be published

at a later date.

Signed:

Print Name:

Dates of Testing:

56

APPENDIX B

Participation Questionnaire

57

58

I.D.#

Soccer Project

Participation Questionnaire

This project is being administered by a graduate student from

Humboldt State University, and your participation is greatly

appreciated. Answering this questionnaire is completely

voluntary and the results will be kept confidential. Please

be thoughtful and honest in your answers. Thank you for your

time and cooperation.

Instructions: Please complete the following questionnaire

to the best of your ability. Upon completion, please place

the questionnaire in the envelope at the front of the room.

Questions:

1) Age: Grade:

2) Gender (circle one): Boy Girl

3) Number of years played on a soccer team:

4) Favorite/Preferred Foot (circle one): Left Right

5) Favorite/Preferred Hand (circle one): Left Right

6) List other sports teams you play on:

7) List the things you and your friends like to do when you

are playing:

59

8) List the things you like to do when you are not

playing:

9) Do you watch soccer on TV? (circle one): Yes No

If Yes, how many games have you seen?

(circle one): 1-3 4-6 7-10 more than 10

10) Have you attended any professional or college soccer

games? (circle one): Yes No

If Yes, how many games have you attended

(circle one): 1-3 4-6 7-10 more than 10

11) What other sports do you watch on TV?

12) What other sporting events have you attended?

13) Do either of your parents play soccer, or have they ever

played soccer? (circle one): Yes No

14) Do any of your brothers or sisters play soccer?

(circle one): Yes No

15) Do any of your friends play soccer?

(circle one): Yes No

16) What is your favorite subject in school?

17) (OPTIONAL) What is your ethnicity? (circle one):

Asian Native American African American

Hispanic Caucasian Other

Thanks again for your cooperation:

APPENDIX C

Score Sheets

60

61

I.D. *:

Pretest

Attempt #* Foot Used Accuracy Velocity

1 R 2 R

3 R

4 R 5 R

6 R 7 R 8 R 9 R 10 R 11 L 12 L

13 L

14 L 15 L

16 L 17 L

18 L

19 L 20 L

Posttest

Attempt* Foot Used Accuracy. Velocity

1

2 R

3 R

4 R

5 R

6 R

7 R

8 R 9 R

10 R

11 L

12 L

13 L

14 L

15 L 16 L

17 L

18 L

19 L

20 L

Mean of Accuracy = Mean of Accuracy =

Mean of VelociAccuracy of Velocity =

Score Keeper: Score Keeper:

(Please Print)

(Please Print)

Signature: Signature:

Date: Date:

Notes: Notes:

Scoresheet A

I.D.

Pretest

Attempt * Foot Used Accuracy Velocity

1 L 2 L 3 L 4 I, 5 L 6 L 7 L

8 L

9 L 10 L 11 R

12 R

13 R 14 R

15 R 16 R

17 R

18 R

19 R 20 R

Posttest

Attempt* Foot Used Accuracy Velocity

1 L 2 L

3 L

4 L

5 L

6 L

7 L

8 L

9 L

L

10 L

11 R

12 R

13 R

14 R 15 R

16 R

17 R

18 R

19 R 20 R

62

Mean of Accuracy = Mean of Accuracy =

Mean of Velocity = Mean of Velocity =

Score Keeper: Score Keeper:

(Please Print)

(Please Print)

Signature: Signature:

Date: Date:

Notes: Notes:

Scoresheet B

63

I.D. #:

Pretest

Attempt # Foot Used Accuracy Velocity

1 R 2 L 3 R 4 L 5 R 6 L 7 R 8 L 9 R 10 L 11 R 12 L 13 R 14 L 15 R 16 L 17 R 18 L 19 R 20 L

Posttest

Attempt # Foot Used Accuracy Velocity

1 R

2 L 3 R

4 L 5 R

6 L

7 R

8 L

9 R

10 L 11 R

12 L

13 R

14 L

15 R

16 L 17 R

18 L

19 R

20 L

Mean of Accuracy = Mean of Accuracy =

Mean of Velocity = Mean of Velocity =

Score Keeper: Score Keeper:

(Please Print) (Please Print)

Signature: Signature:

Date: Date:

Notes: Notes:

Scoresheet C

I.D. #:

Pretest

Attempt # Foot Used Accuracy Velocity

1 L 2 R

3 L 4 R 5 L 6 R 7 L 8 R 9 L

10 R 11 L 12 R

13 L 14 R 15 L 16 R 17 L 18 R

19 L 20 R

Posttest

Attempt # Foot Used Accuracy Velocity

1 L

2 R 3 L 4 R 5 L 6 R

7 L

8 R

9 L

10 R

11 L 12 R

13 L 14 R

15 L

16 R

17 L

18 R 19 L

20 R

64

Mean of Accuracy = Mean of Accuracy =

Mean of Velocity = Mean of Velocity =

Score Keeper: Score Keeper:

(Please Print)

(Please Print)

Signature: Signature:

Date: Date:

Notes: Notes:

Scoresheet D

APPENDIX D

Instruction/Demonstration Directions of Instep Drive

65

66

Instruction/Demonstration Topics

To successfully perform the instep drive, there are many components that must be completed properly. However, there are 5 basic components that are easy to remember, and if followed, will greatly improve the chance of making a successful kick. Those basic components are the approach, plant foot, large last step, point toe/lock ankle, and striking middle portion of the ball.

There will be a brief discussion and demonstration of each component prior to the 5 practice sessions. The order in which the topics will be covered are as follows:

I. THE APPROACH (Coaching Points) A. Start behind the ball @3-4 steps, whatever is

most comfortable. B. Do not approach ball in straight line to

target. C. Approach the ball from an angle.

1. This makes swinging the leg easier.

II. THE PLANT FOOT (Coaching Points) A. This component is very important for 2

reasons. 1. Accuracy. Point the plant foot toe

toward the target. 2. Power. Foot should be next to

ball, but not too close.

III. LARGE LAST STEP (Coaching Points) A. This component has 2 purposes.

1. Momentum. Gets the body's momentum moving towards target.

2. Backswing. Gets the striking leg in its back swing motion.

IV. POINT TOE/LOCK ANKLE (Coaching Points) A. This will keep you from injury if miss hit

ball. B. Makes for more consistent striking of ball

with power and accuracy. C. No Noodle Ankles

V. STRIKE BALL JUST BELOW MIDLINE (Coaching Points) A. Strike ball too low, and the ball goes too

high. B. Strike ball too high, and the ball will not

leave the ground. C. Strike ball just below center of ball & you

should get desired trajectory.

APPENDIX E

Human Subjects Committee Letter

67

68

*MEMORANDUM*

Office of the Dean College of Natural Resources and Sciences

DATE: October 24, 1997

TO: Kathy Munoz, Assistant Professor, Health and Physical Education Paul Stumpf, Department of Kinesiology

FROM: Warren Carlson, Chair Committee for the Protection of Human Subjects in earch

SUBJECT: Your Proposal: "Practice Order Effect on Bilateral Transfer of the Instep Drive in Soccer"

Thank you for submitting your proposal, "Practice Order Effect on Bilateral Transfer of the Instep Drive in Soccer" for research using human subjects. As you know, the Committee for the Protection of Human Subjects in Research met on October 24, 1997, to discuss your proposal. Thank you for joining us.

The committee members were assured that risks to subjects have been minimized, and that appropriate subject protections are planned.

This memo constitutes formal approval of your research proposal. This approval is for one calendar year and will expire on October 24, 1998. If you find it necessary to continue your research beyond this date, please apply for renewed approval in enough time in advance of this date to prevent interruptions in your project. If your research plan must be altered, please notify this office according to the policies established for Humboldt State University. Your proposal will be filed with the permanent records of human subjects research at Humboldt State University.

Thank you for your careful attention to the protection of the human subjects of your research.

cc: Members of the Committee for the Protection of Human Subjects in Research Leslie Foote, Arcata Family Medical Group Chris Hopper, Health and Physical Education Senqi Hu, Psychology Diane Johnson, Mathematics Terrie Jordan, Disabled Students Richard Langford, Psychology Beverly Nachem, Nursing Patrick Wenger, Anthropology

Arcata. California 95521-8299 • (707) 826-3256 • Fax (707) 826-3562 • cnrsdean@laurel.humboldt.edu