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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 • [email protected]