HIGH SCHOOL COACHES’KNOWLEDGE OF PLYOMETRIC EXERCISE

A THESIS
Submitted to the Faculty of the School of Graduate Studies
and Research
of
California University of Pennsylvania in partial
fulfillment of the requirements for the degree of
Master of Science

by
Paul Rucci

Research Advisor, Dr. Shelly DiCesaro
California, Pennsylvania
2012

ii

iii

ACKNOWLEDGEMENTS
I would like to take this time to recognize the people
who have made the most impact in my life, without their
guidance I would not have had the courage to complete this
task. First, I would like to thank my advisor Dr. Tom West,
my chair person Dr. Shelly DiCesaro, and my committee
members James Daley, and Dr. Ayanna Lyles. Without their
expertise, knowledge, experience, and most importantly
confidence in me, I would not have been able to take on and
complete this huge task of completing my thesis and my
master’s work. I know at times I seemed to lose faith in
this process and seemed to fly off the handle, but you were
always there to help me out and get me back on course.
Shelly, you have taught me so much about staying calm
and really taking a breath when I need it most. Without
your help and guidance, I know I could not have completed
this thesis. The lessons you taught me will go far beyond
this year and I hope to carry them with me for the rest of
my life.
I would like to also thank the entire faculty in the
athletic training department. Without the help of Ms.
Carolyn Robinson I know this process would have been even
more difficult. I have learned so much about what it takes

iv
to be a professional in this field during my time here. To
all my baseball and softball athletes I would like to thank
you for providing me with a fantastic experience and for
keeping me on my toes this year. Lastly, to my classmates,
this year has truly been a blast and I will miss you all
dearly. I have had so much fun getting to know you all and
spending this year of my life with you. I would also like
to acknowledge Curt Snyder’s Mustache, which brightened my
day, reminded me to laugh, and allowed me to be a free
spirit and an overall better person each and every day I
set foot in the athletic training room.
Finally, I would like to thank my whole family back
home in Maine and in New York. Without your love and
support this process simply could not have happened. You
were there to guide me at every new turn I have had in my
life in the past year and have always has the confidence in
me to be successful. I love you all very much. Without all
of you this process may have never been completed and for
that I am forever grateful. THANK YOU ALL!!

v
TABLE OF CONTENTS
Page
SIGNATURE PAGE

. . . . . . . . . . . . . . . ii

AKNOWLEDGEMENTS . . . . . . . . . . . . . . . iii
TABLE OF CONTENTS
LIST OF TABLES
INTRODUCTION
METHODS

. . . . . . . . . . . . . . v

. . . . . . . . . . . . . . . vii

. . . . . . . . . . . . . . . . 1

. . . . . . . . . . . . . . . . . . 6

Research Design
Subjects

. . . . . . . . . . . . . . 6

. . . . . . . . . . . . . . . . . 7

Preliminary Research. . . . . . . . . . . . . 7
Instruments . . . . . . . . . . . . . . . . 7
Procedures

. . . . . . . . . . . . . . . . 8

Hypothesis(or Hypotheses). . . . . . . . . . . 9
Data Analysis
RESULTS

. . . . . . . . . . . . . . . 9

. . . . . . . . . . . . . . . . . 11

Reliability

. . . . . . . . . . . . . . . . 11

Demographic Data

. . . . . . . . . . . . . . 13

Hypothesis Testing

. . . . . . . . . . . . . 13

DISCUSSION . . . . . . . . . . . . . . . . . 17
Discussion of Results

. . . . . . . . . . . . 17

Conclusion . . . . . . . . . . . . . . . . . 22
Recommendations for Future Research . . . . . . . 23
REFERENCES . . . . . . . . . . . . . . . . . 24

vi
APPENDICES . . . . . . . . . . . . . . . . . 26
APPENDIX A: Review of Literature

. . . . . . . . 27

Plyometrics . . . . . . . . . . . . . . . . 29
Stretch Shortening Cycle . . . . . . . . . . 32
Design of Plymetric Training . . . . . . . . 34
Plyometric Traini ng Effects on Lower Extremity 38
Plyometric Training vs. Resistance Training . 42
Coaches’ Knowledge of Plyometric Exercise . . 45
Summary . . . . . . . . . . . . . . . . . . 47
APPENDIX B: The Problem . . . . . . . . . . . . 49
Statement of the Problem . . . . . . . . . . . 50
Definition of Terms . . . . . . . . . . . . . 51
Basic Assumptions . . . . . . . . . . . . . . 52
Limitations of the Study . . . . . . . . . . . 52
Significance of the Study

. . . . . . . . . . 53

APPENDIX C: Additional Methods .

. . . . . . . . 54

High School Coaches’of Plyometric Exercise Survey . 55
IRB: California University of Pennsylvania (C2) . . 63
Coverletter (C3) . . . . . . . . . . . . . . 75
REFERENCES
ABSTRACT

. . . . . . . . . . . . . . . . 78
. . . . . . . . . . . . . . . . . 81

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LIST OF TABLES

Table

Page

1

Initial and follow up test scores . . . . . . . 12

2

Mean scores between coaches’ gender . . . . . . 14

3

Knowledge scores between male and female
sports . . . . . . . . . . . . . . . . . . 15

4

Plyometric scores between different age
groups . . . . . . . . . . . . . . . . . . 15

5

Significance between coaches age groups

. . . . 16

1

INTRODUCTION

Plyometric exercises are one technique used by
athletes to increase maximal power output and jumping
ability in sports. Plyometric training is an established
technique for enhancing athletic performance but may also
facilitate beneficial adaptations in the sensorimotor
system that enhances dynamic restraint mechanisms and
corrects faulty jumping or cutting mechanics, thus reducing
the chance for lower extremity injury such as Anterior
Cruciate Ligament tears.1
One of the primary training goals of plyometric
exercises is to increase maximal power output and jumping
ability.2-4 Using plyometric training in a safe and correct
manner has been shown to produce many positive results such
as increased jump height, development of muscle power, and
increase muscular endurance.1,2
Coaches may be aware of plyometrics and how they can
be used to help benefit athletes, but may not know how to
perform them safely and implement them effectively into
their team workouts. There are multiple training programs
that are readily available to high school coaches, but an

2
exhaustive search of the literature examining the extent at
which coaches use plyometrics effectively and safely when
training their athletes is still widely unknown.2
Plyometric training is based on the Stretch Shortening
Cycle.(SSC) When muscles undergo rapid eccentric elongation
just before rapid concentric contraction it is known as the
stretch-shortening cycle (SSC).5,6 The muscle is essentially
stretched while loaded, resulting in greater force
generated during a subsequent concentric contraction from a
static position2. The rapid change in contraction allows for
better performance such as increased vertical jump height
and power output. If a muscle has the ability to adapt to
the SSC it enables the individual performing the action to
generate greater power.6 The Stretch-Shortening Cycle is
important to athletes because generating a greater amount
of power can have positive effects on athletic performance
such has increased vertical jump and faster sprint speed.
For coaches to effectively implement plyometric
training with their athletes they must address several
important training factors.

Two major factors in

determining the success of a plyometic training program is
progression and recovery.7 A few common signs that an
individual may not be ready to progress within their
program are: 1).If the athlete shows extensive bending at

3
the waist or their torso produces excessive forward flexion
or lateral bending, more core work may be needed; and 2).
If the athlete exhibits prolonged contact with the floor,
they may not have the overall body strength and power
necessary to proceed.3 If the athlete's knees are collapsing
towards each other producing genu valgus, this may mean
lack of quadriceps strength. This can occur on landing
during the eccentric contraction or on push-off of the
concentric phase. If the level of exercise is not
decreased, these movements can lead to joint pain,
tendinopathies, excessive muscle fatigue of the legs, and a
decreased demonstrated ability to explode.

Without allowing

for proper recovery, fatigued muscles will cause the
athlete to have poor and improper exercise techniques which
may lead to injury. It is crucial an individual’s
techniques are performed properly to avoid injury.
Additionally, it is crucial that recovery time is adequate,
otherwise the athlete may become susceptible to
overtraining.8 In a recent study performed by Luebbers and
Potteiger, the importance of a recovery period following a
plyometric program was examined. The study showed when
participants were allowed four weeks to recover, that
period of recovery had a powerful effect upon performance.
It is unclear if the results would have increased more with

4
a longer recovery, but it is clear that a recovery period
should be included following a plyometric training program
to achieve maximum results.6
Intensity also plays a crucial role in plyometric
exercise. In plyometrics, the intensity of a training
session is determined by the exercises that are being
performed or the rate of the SSC. Plyometric exercises can
range from within a wide variety of intensities. Exercises
such as core twists would be fairly low in intensity while
box depth jump exercises would be very high in intensity.
Lastly, volume is a vital piece of information crucial to a
successful plyometric program.11
Volume in plyometric exercises is determined by the
number of foot touches within a training period. Foot
touches may vary due to participant’s age, gender, or
experience. Volume measured in foot touches is inversely
related to training intensity. The more foot touches per
workout, the lower the intensity should be and the less
foot touches per workout, the higher intensity. Therefore,
low intensity programs will consist of about 400 foot
touches per workout while high intensity workouts consist
of anywhere from 250- to 300 foot touches.12
Plyometric exercise has been proven to increase
muscle output, power, endurance, and vertical jump height

5
as well as decrease the risk of injury.1-4 The purpose of
this study is to examine high school coaches’ level of
knowledge of plyometric training. Plyometric training that
is done incorrectly can result in injury and/or have
negative effects on performance.

6

METHODS

The purpose of this study was to determine high school
coaches’ knowledge of plyometric exercise. This section
includes the following subsections: Research Design,
Subjects, Preliminary Research, Instruments, Procedures,
Hypotheses, and Data Analysis.

Research Design

A descriptive design was used in this study with data
collected via a web based survey. The primary purpose of
this study was to examine the knowledge of plyometric
exercise amongst high school coaches. The dependent
variable of this study was coaches’ knowledge of plyometric
exercise. The independent variables of this study include:
the coaches gender, the gender of the sport they coached,
and their age.
A strength of this study is content validity was
established for the survey after a review by a panel of
experts. Limitations of this study are only high school
coaches in Pennsylvania were survey, the survey cannot be
distributed directly to high school coaches in the

7
Pennsylvania Interscholastic Athletic Association (PIAA),
and the survey was not generalized to the entire population
of coaches in the United States.

Subjects

Subjects in this study were composed of high school
coaches in the Pennsylvania Interscholastic Athletic
Association (PIAA) throughout the state of Pennsylvania.

Preliminary Research

Prior to distribution of the survey to subjects, the
survey was completed by 6 coaches at the collegiate level
to determine reliability. A Pearson Product moment
correlation was performed to determine correlation
coefficients for each question as well as the survey as a
whole.

Instruments

The Knowledge of Plyometric Training Survey (Appendix
C4) was used in this study. The survey was developed by the
researcher to determine knowledge of plyometric training

8
amongst high school coaches. The survey consists of ten
demographic questions and twenty questions pertaining
specifically to plyometric training. These questions were
based on published literature on plyometrics.

Procedures

Approval from California University of Pennsylvania’s
Institutional Review Board for Protection of Human Subjects
form (Appendix C2) was obtained prior to data collection.
The survey was read for content and faced validity by a
group of experts in the field of athletic training. The
following procedure was followed to distribute:
1. An email containing a cover letter explaining the
study with a link to the survey was emailed to the
executive director of the PIAA.
2. The executive director forwarded the cover letter and
link to surveymonkeyTM to all athletic directors within
the PIAA.
3. Athletic directors then forwarded the email to their
respective high school coaches.
4. High school coaches had 4 weeks to complete the online
survey.

9
5. Reminder emails were sent at week 2 to remind the
coaches to complete the survey.
Once the data collection was complete, the researcher
downloaded the data to SPSS 18.0 for data analysis.

Hypotheses

The following hypotheses are based upon previous
research after a review of the literature.
1. There will be no significant difference in plyometric
knowledge test scores between coaches of different
gender at the high school level.
2. There will be no significant difference in plyometric
knowledge test scores between coaches of female versus
male sports at the high school level.
3.

There will be no significant difference in
plyometric knowledge test scores between coaches
based on number of years coaching.

Data Analysis

The first two hypotheses were measured using a one-way
T- Test while the second two hypotheses were tested through

10
the use of ANOVA. For all hypotheses alpha was set at a p
<.05.

11

RESULTS

The purpose of this study was to determine
Pennsylvania high school coaches’ knowledge of plyometic
exercise. Data was collected via an online survey using
Surveymonkey™ and was accessible for four weeks for all
coaches within the Pennsylvania Interscholastic Athletic
Association (PIAA). This section has been divided into the
following sections: reliability testing, demographics and
hypothesis testing.

Validity

The High School Coaches’ Knowledge of Plyometric
Exercise survey was reviewed for face and content validity
by a group of experts from University of Maine at Presque
Isle and California University of Pennsylvania.

Reliability testing

The High School Coaches’ Knowledge of Plyometric
Exercise survey was created by the researcher based on
previous surveys and literature pertaining to plyometric

12
exercise.

Reliability of the survey instrument was

obtained through the use of six collegiate coaches at
California University of Pennsylvania. The survey was
administered twice and received equal responses after the
second administration 2 weeks later. The Data was
consistent when analyzed by the researcher and deemed
reliable. With a Pearson Product moment correlation
coefficient (r(6)=.984, p<0.05), indicated a significant
linear relationship between the two tests and a strong
positive correlation. This is shown in table 1 below.
Table 1. Initial and follow up test scores
Source
Pre
Post
Initial
Person
1
.984*
Correlation
Sig. (21
.000
tailed)
N
6
6
Follow up
Person
.984* 1
Correlation
Sig. (2.000
tailed)
N
6
6
**Correlation is significant at the 0.05 level (2-tailed)

A Cronbach’s Alpha scale was also used to test
reliability for this survey. A score of .670 was found.

13
Demographic Data

The director of the PIAA forwarded a link of the survey to
all coaches in the PIAA.

Total number of surveys sent was

unattainable due to third party distribution. One hundered
fourty-nine coaches logged onto survey monkey and submitted
a survey, however, due to incomplete data, 82 surveys were
used for the first hypothesis, 78 surveys were used for the
second hypothesis and 88 surveys were useable for the third
hypothesis.

Hypothesis Testing

The first two hypotheses were measured using a one-way
T- Test while the second two hypotheses were tested through
the use of ANOVA. For all hypotheses alpha was set at a p
<.05.

Hypothesis 1. There will be no significant difference in
plyometric knowledge test scores between coaches gender at
the high school level.
Conclusion: An independent-samples t test was calculated
comparing the mean score of participants who identified
themselves as male (n=62) to the mean score of participants

14
who identified themselves as female (n=20). No significant
difference was found. The difference between the mean score
of the male group (m=6.76, sd=±3.486) was not statistically
significant from the mean of the female group (m=6.75,
sd=±2.403, p=.188 p<0.05). Table 2 shows the mean scores
between coaches gender.
Table 2. Mean scores between coaches gender
Std.
Gender
N
Mean
Deviatio
n
Male
62
6.67
3.486
Female
20
6.75
2.403

P-Value

.188

Hypothesis 2. There will be no significant difference in
plyometric knowledge test scores between coaches of female
versus male sports at the high school level.

Conclusion: An independent samples t-test was calculated to
test significance of hypothesis 2. The difference of the
mean score of the male sport (coaches) compared to the
female sport (coaches) was found to not be statistically
significant. (Males= 6.98, sd ±3.984, Females=6.65, sd
±2.791,p=.170). This is displayed below in table 3.

15

Table 3. Knowledge scores between male sports vs. female
sports
P-Value
Std.
Sport
N
Mean
Deviation
Male Sport
41
6.98
3.684
.170
Female Sport
37
6.65
2.7191

Hypothesis 3. There will be no significant difference in
plyometric knowledge test scores between coaches based on
the coaches’ age.
Conclusion: The coaches’ ages ranged between 18-60 years
(or older.) Scores in different age groups did not show
significant differences as shown in table 4. Additionally,
age group distribution is shown below in Table 5.
Table 4. Plyometric scores between different age groups
Sum of
Sig.
Squares
Df
Mean Square F
Between
8.924
5
1.785
.162
.976
Groups
Within
904.519
82
11.031
Groups
Total
913.443
87

16

Table 5. Significance between coaches' age groups
Std.
Std. Error
Age Group
N
Mean
Deviation
2. 18-20 yr. old
1
8.00
3. 20-29 yr. old
16
6.88
3.181
.795
4. 30-39 yr. old
5. 40-49 yr. old
6. 50-59 yr. old
7. 60-above yr.
old
Total

29
20
17
5

6.62
6.30
7.06
6.20

3.133
3.771
3.363
2.588

.582
.843
.816
1.158

88

6.67

3.240

.345

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DISCUSSION

In discussion of the findings of this study, the
following sections are presented: (1) Discussion of
Results,(2) Conclusions, and (3) Recommendations for Future
Research.

Discussion of Results

This study was conducted to investigate Pennsylvania
high school coaches’ knowledge of plyometric exercise. One
of the primary training goals of plyometric exercise is to
increase maximal power output and jumping ability, which
when used in a safe and correct manner has been shown to
produce positive results such as increased jump height,
development of muscle power, and increase muscular
endurance.1,2-4 Additionally, plyometric exercise has been
shown to potentially decrease lower extremity injuries when
implemented in a safe and effective manner1-4 Although
coaches may be aware of what plyometric exercises are,
their knowledge of how to perform plyometrics in a safe and
beneficial manner are still widely unknown.2

18
The results of this study found there were no
significant knowledge score differences between male and
female coaches or the gender of which they coached. As
previously mentioned, plyometrics have been used
effectively to decrease lower extremity injuries,
particularly in female athletes1-4.
A study performed by Mandelbaum et al.17 looked to
determine whether a neuromuscular and proprioceptive
performance program was effective in decreasing the
incidence of ACL injuries in young female athletes. The
athletes were asked to perform a sport specific training
intervention in the trial. The intervention consisted of
education, stretching, strengthening, plyometrics, and
sport specific agility drills. The study consisted of a
female sport training group and a control group made up of
girls of the same age group in the same league. Results
concluded that during the season, there was an 88% decrease
in ACL injuries in the enrolled subjects compared to the
control group. In the next season there was also a 74%
reduction of this same injury.
The conclusion from this study was that using a
training program such as plyometrics could have a direct
benefit in decreasing the number of ACL injuries in
females.17

This would lead one to believe female coaches as

19
well coaches of female athletes would have a particular
interest in implementing plyometrics into their programs.
Sports that involve explosive jumping, cutting, and
sprinting are more likely to use plyometric exercise to
increase vertical jump height and power, such as
basketball.2-5 Additionally it was hypothesized there would
be no significant difference in scores between coaches of
female verses male sports at the high school level. The
theory behind this hypothesis is that coaches of female
sports would recognize the significant differences in lower
extremity injury rate amongst their female athletes
compared to male’s injury rate of ACL tears.2-5
Lastly, we hypothesized there would be no significant
difference in plyometric knowledge test scores between
coaches age groups. Because plyometric training is a
relatively new technique, the researcher believed that the
younger coaches would be more knowledgeable with this type
of training due to the fact that it may have been a
technique they performed as younger athletes. Coaches that
were older in the age groups may have been "set in their
ways" of training and have not adapted the more recent
techniques like plyometric exercise, thus leading to lower
scores. However, results showed that all age groups scored
very similarly in this study.

20
Recently, mild traumatic brain injury or concussion,
has received an enormous amount of attention in both the
medical world and media. Research has also been conducted,
similar to ours, investigating coaches’ knowledge of
concussion prevention, recognition and treatment.14 Studies
investigating concussion awareness and coaches have shown
recent knowledge improvement over the last decade.14-15. This
may be attributed to recent campaigns to increase coaches
knowledge of the recognition and treatment of concussions
which has shown to produce positive results when working
with athletes who have suffered a brain injury.14
In a study by Guilmette et al., coaches’ knowledge of
concussions was surveyed.14 After the baseline test, coaches
were given a review of Heads Up, educational materials
focusing on concussion and coach recognition. Seventy
percent of coaches who had received and reviewed the
material reported the information provided to be very
helpful. Included in the material was information on
educating coaches about all aspects of a concussion injury.
When asked about how the coaches planned to use the
materials, a significant majority reported they planned to
give it to athletes and parents. Overall, the study
concluded that coaches seemed eager and willing to learn

21
more about concussions if the material were made available
to them.14
Another recent study by Sawyer et al. evaluated
coaches’ perceptions, assessment, and use of a "toolkit"
that was sent to high school coaches on how to prevent and
manage concussions among high school athletes. The kit
included a facts sheet, posters and a video. Upon telephone
follow up, most coaches reported that they had used or
planned to use the kit materials with their athletes.
Eighty-one percent of schools with a written plan for
preventing and managing concussions said that the toolkit
could be used to improve their current plan and 96% of
coaches who did not have a plan indicated that the kit
could be used to develop one. Coaches agreed that a
visually appealing kit that was easy to understand would be
beneficial to their teams.

To conclude, this study

provided confirmation that the toolkit should be viewed as
appealing and useful material for high school coaches and
is likely to contribute to increased prevention and
improved management of concussions amongst high school
athletes.15
The previous studies show that coaches are willing to
implement changes if given the right materials. If coaches
are receptive to informative videos, posters, or handouts

22
on concussions, perhaps the same educational techniques
could be used for those coaches who wish to incorporate
plyometric exercise into their workouts.

Conclusion

The findings of this research provide some insight of
high school coach’s knowledge of plyometric exercise in the
state of Pennsylvania. Although none of the hypotheses were
found to be significant, it is worth noting the average
scores of the survey were very low with mean scores of 6
correct, well below 50% correct for the survey. I believe
this may have occurred in part due to complexity of as well
as the concepts involved with understanding plyometrics.
Without correct knowledge of volume, intensity, rest time,
periodization, and proper technique it is very difficult to
understand the principals of plyometric training. A firm
understanding of biomechanics, exercise physiology, and
strength training is needed to incorporate plyometrics in a
safe and effective manner. Often times coaches have not had
experience or education with plyometrics and this may lead
to improper training programs and an increased risk of
injury. If coaches wish to implement plyometric training, I

23
think that is important for them to first have the correct
knowledge of plyometric exercise.

Recommendations for Future Research

The research study, Coaches Knowledge of Plyometric
Exercise has investigated a limited population of coaches
within the state of Pennsylvania. The results of the study
have yielded a few primary recommendations by the
researcher for future research on this subject.
The survey should be distributed more efficiently,
specifically, by the researcher themselves, instead of
relying on a third party. Ensuring the survey and
researcher is more easily accessible to coaches may
increase the rate of return.
The second recommendation is to focus on high school
coaches that do currently implement plyometric exercise in
their programs rather than coaches who may or may not use
them. If coaches who use plyometrics are the only ones to
respond, it may be able possible to get a clearer
assessment of their knowledge of plyometric exercise and
how they implement them at their high school setting.

24
REFERENCES

1.

Plowman S, & Smith. Exercise physiology. Baltimore:
Lippincott Williams&Wilkins;2009:525-526.

2.

Markovic G. Does plyometric training improve vertical
jump height? A meta-analytical review. Br J Sports
Med.2007;41:349–355. DOI :10.1136/bjsm.2007.035113.

3.

Bobbert MF. Drop jumping as a training method for
jumping ability. Sports Med.1990;9:7-22.

4.

Lundin P, Berg W. Plyometrics: a review of plyometric
training. Nat Strength Cond Assoc J. 1991;13:22-34.

5.

Makaruk H, Sacewicz T. Effects of Plyometric Training
on Maximal Power Output and Jumping Ability. Human
Movement.2010;11:17-22. Accessed June 2, 2011.

6.

Komi PV. Stretch-shortening cycle: a powerful model to
study normal and fatigued muscle. J Biomech.2000;
33:1197–1206.

7.

Potteiger J, Lockwood R, Haub M, et al. Muscle Power
and Fiber Characteristics Following 8 Weeks of
Plyometric Training. Journal of Strength and
Conditioning.1999;13:274-279. Accessed June 22, 2011.

8.

Chu D. Jumping into Plyometrics. 2nd ed.Champaign,
III: Human Kinetics.1998.

9.

McClellan T. Big jumps. Training and Conditioning.
2005;40-50.

10.

Luebbers PE, Potteiger JA, Hulver MW, et al. Effects
of plyometric training and recovery on vertical jump
performance and anaerobic power. J Strength
Conditioning.2004;17:704-902

11.

McClellan T. Big jumps. Training and Conditioning.
March 2005;42-46

12.

Clark M, Lucett S.Sports performance training.
Baltimore: Lippincott Williams &Wilkins.

25
13.

Krejcie RV, Morgan DW. Determining sample size for
research activities. Educ Psychol Meas.1970;30:607610.

14.

Guilmette T, Malia L, McQuiggan M. High school coaches
knowledge of sport related concussion. Brain
Injury.2007; 21:1039-1047.
http://web.ebscohost.com.navigatorcup.passhe.edu/ehost/resultsadvanced?sid+aa54cee94b39-47e3-8b9a. Accessed July 20, 2011.

15.

Sawyer J, Hamdallah M, White T, et al. High school
coaches’ assessments, intentions. Health Promotions
Practice.2008;34-43. July 20,2011.

16.

Harrington L. The Effects of 4 Weeks of Jump Training
on Landing Knee Valgus and Grossover Hop Performance
in Female Basketball Players. Journal of Strength and
Conditioning.2010;24:3427-3432.Accessed June 30, 2011

17.

Mandelbaum B, Silvers H, Watanabe T, et al.
Effectiveness of neuromuscular and proprioceptive
training program in preventing anterior cruciate
ligament injuries in female athletes . The Amercian
Journal of Sports Medicine.2005;33:1003-1010.

26

APPENDICES

27

APPENDIX A
Review of Literature

28
REVIEW OF THE LITERATURE

Plyometric exercise at the high school level is
becoming a popular training technique used by high school
coaches. Plyometric exercises are used primarily to
increase maximal power output and jumping ability.
Plyometric training is an established technique for
enhancing athletic performance but may also facilitate
beneficial adaptations in the sensorimotor system that
enhance dynamic restraint mechanisms and correct faulty
jumping or cutting mechanics.1
Ploymetric training has been shown to increase
vertical jump performance. Vertical jumping is affected by
muscular and neural aspects alike.

In order for a subject

to jump higher, the greatest amount of vertical
acceleration needs to be achieved before leaving the
ground. The acceleration creates initial vertical velocity.
The greater the velocity, the higher the center of mass
will reach.

In order to achieve the greatest vertical

acceleration, the individual needs to create as much force
as possible over the shortest amount of time. It is crucial
that by increasing muscle mass and by training neural
mechanisms alike, an athlete can jump higher and react
faster.2 Some other advantages of plyometric training is it

29
increases functional power and allows the muscles to reach
a higher power level. Plyometric training has also been
shown to decrease muscle reflex inhibition, increases the
sensitivity of the Golgi tendon organs, improve the
sensitivity of the muscle spindles, and increases muscle
tension while reducing risk of injury.3-8 These may all in
turn, increase performance while also decreasing the risk
of injury.
This review of the literature aims to explain
plyometric exercise and its scientific benefits as well as
high school coach’s knowledge of plyometric training
including the knowledge of risks, benefits, routine
schedule, and sources of information. The information will
be broken into the following sections: defining plyometric
training, plyometric training effects on the lower
extremity, effects of various types of plyometric programs,
and high school coach’s knowledge of plyometric exercise.

Plyometric Training

Plyometric exercise is defined as eccentric loading
immediately followed by a concentric contraction.9 Research
has shown that the main goal of plyometric training is to
increase maximal power output and also increase vertical

30
jump height. This can be achieved thru exercises that
include bounding, hopping, and other jumping exercises with
one or two legs.10-11 In order to understand how plyometric
exercises work, one must first understand basic muscle
physiology and the actions that the muscles will perform
during plyometric exercise.
Muscles have the ability to both passively lengthen
and contract. Having the ability to lengthen and contract
allows us to perform dynamic movements of the body. Each
muscle fiber contains thousands of smaller rodlike strands
referred to as myofibrils.

Myofibrils are contractile

structures made of myofilaments.

The myofibrils lie

parallel to the long axis of the muscle cell and extend the
length of the muscle. The myofibrils function to contract,
elongate, or relax a muscle.1
Also involved in the contraction of muscle are Golgi
tendon organs (GTOs). The GTOs are located in the muscletendon junctions and in the tendons at both ends of the
muscles. These receptors are stimulated by tension in the
muscle-tendon unit.

GTOs detect tension in the muscle and

cause the muscle to act upon the change of tension by
contracting or lengthening. Both myofibrils and GTOs play
an important role in contraction during plyometric
exercise. When the muscle is contracted or lengthened

31
during jumping, the GTO’s detect the change of length in
the muscle and quickly act upon that change.1
Muscle contractions are the basis for all human
movement, and our muscles have 4 characteristics that allow
a muscle to produce movement.

These 4 characteristics

include irritability, contractility, extensibility and
elasticity. Irritability refers to the ability of a muscle
to receive and respond to stimuli via chemical message from
a neurotransmitter, and then in turn, respond with an
electrical current to produce movement. Contractility is
the ability of a muscle to shorten when responding to
stimuli. Contractility allows a muscle to produce force.
Elasticity is the ability of the muscle to return to its
resting length after being stretched. The last
characteristic is extensibility, which allows a muscle to
be stretch or lengthened when responding to an external
force.1 The above mentioned characteristics of muscle allow
for 3 different types of dynamic muscle movements. They are
concentric, eccentric, and isometric contractions.
Concentric contraction occurs when a muscle produces
tension during a shortening movement allowing for
acceleration of the body part. Eccentric contraction occurs
when a muscle that produces tension is lengthening.
Eccentric contraction is mainly used to help decelerate a

32
body part. Finally, isometric contraction occurs when a
muscle contracts but does not change its length.1 Plyometric
exercise involves rapid changes of muscle contraction. Much
of a participant’s ability to maximize plyometric muscle
strength relies on the Stretch-Shortening Cycle (SSC).

Stretch-Shortening Cycle
The stretch shortening cycle (SSC) is described
as an eccentric phase or stretch followed by an isometric
transitional period (amortization phase), leading into an
explosive concentric action. The SSC goes together with
plyometrics and is often referred to as the reversible
action of muscles.8
Vertical jump performance relies heavily on the
participant’s ability to use the stretch-shortening cycle
to increase vertical jump height.10 The greater force
produced by the muscle during plyometric training is
related to the storage of elastic energy during muscle
stretch and its rapid release during the shortening
movement. When muscles undergo rapid eccentric elongation
just before rapid concentric contraction it is known as the
Stretch-Shortening Cycle (SSC).10 The muscle is essentially
stretched while active, resulting in a greater force
production during the concentric contraction than could be

33
generated during a subsequent concentric contraction from a
static position. If a muscle has the ability to adapt to
this cycle it enables the individual performing the action
to generate greater power.11
Most sports require jumping, sprinting, or rely on a
combination of strength, speed, and power. Plyometric
exercises are used to increase maximal power output and
jumping ability.10 Makaruk et al. performed a study using 44
non-training individuals. Subjects in the study performed
plyometric exercises twice a week for 6 weeks. The
measurements for this test included maximal power output,
center of mass elevation, rebound time, and knee flexion
angle. It was concluded that there was an increase in
maximal power output during the counter jump movement and
during depth jumps as well as a significant reduction of
rebound time in the depth jump.10 No significant changes in
the center of mass elevation were noted in either jump.
Similarly, Lehnert et al. performed a study to find
the validity of using plyometric training program and its
effects on speed and explosive power in female youth
volleyball athletes. Plyometric exercises were implemented
twice a week for eight weeks. Their level of explosive
power and locomotor speed was evaluated before, during and
after the intervention was completed. The levels were

34
determined with the following tests: the standing vertical
jump, the vertical jump with an approach and the shuttle
run for 6 x 6 m. There were positive changes in the average
values of test scores during the period of testing, but the
dynamics of the changes in the explosive power and the
speed were different.12 Results from the study concluded
plyometric training is effective in increasing power and
speed in young female athletes.

12

Design of Plyometric Training
There are many components within a plyometric training
program, including progression. Progression within exercise
can come from a variety of different ways such as changing
weight, speed, intensity, duration or adding more
exercises. When thinking of progression with plyometric
training exercises you should consider intensity, volume,
and recovery. A few common signs that an individual may not
be ready to progress within their program are: 1).If the
athlete shows extensive bending at the waist or her torso
flops forward or from side-to side, more core work may be
needed. 2). If the athlete exhibits prolonged contact with
the floor, she may not have the overall body strength and
power necessary to proceed. 3). If the athlete's knees are
collapsing towards each other, this can mean lack of

35
quadriceps strength. The collapsing of the knees can occur
on landing during the eccentric contraction or on push-off
of the concentric phase. If the level of exercise is not
decreased, these movements can lead to joint pain,
tendonitis, excessive heaviness of the legs, and a
decreased demonstrated ability to explode. Ideally, the
knees should be aligned over the middle toe of each foot
for all jumping and landing exercises. These progressions
are all interrelated, the higher the intensity, the lower
the volume, the longer rest period.13
Intensity is the amount of energy put forth to
complete an exercise. In plyometrics, the intensity of a
training session is determined by the exercises that are
being performed or the rate of the SSC. Intensity has been
defined as the amount of stress the plyometric drill places
on the muscle, connective tissue, and joint.13-14 Plyometric
exercises can stretch from a wide variety of intensity.

An

exercise such as core twists would have low intensity
whereas box jumps would have a very high intensity. Volume
is also a vital piece to successful plyometrics.13
Within plyometrics the number of foot touches would
account for the volume of a plyometric training exercise.
The number of foot touches an individual may have may be
dependent of factors such as age, weight, skill level, or

36
exercise preference.13 Plyometrics can range from low to
very high intensity. It is important to remember that in
plyometrics, foot touches and volume are inversely related.
Therefore, low intensity should be approximately 400 foot
contacts a session, moderate intensity should be around 350
foot contacts a session, high intensity may consist of
around 300 foot contacts a session, and very high intensity
plyometrics should consist of about 200 foot contacts. The
lower the number of foot contacts, the higher the
intensity. Individuals with minimal experience using
plyometrics should keep the ground contacts to less than
100 maximal efforts per session, whereas those with more
experience could have as many as 120-140 maximal effort
ground contracts per session.15
Recovery is essential to execute a successful
plyometric training program.9 When performing a plyometric
program, recovery can have multiple meanings. Recovery can
be the recovery time in between sets of an exercise and the
rest time between workouts. In order to perform plyometric
exercises correctly, the individual must have proper rest
times in between exercises and proper recovery times after
each workout. The effectiveness of a plyometric training
session depends on maximal effort and a high speed of
movement for each repetition. Rest intervals between

37
repetitions and sets should be long enough to allow almost
complete recover.16 As much as 5-10 seconds may be required
between depth jumps and a work to rest ratio of 1:10 is
recommended. For example, if a set of bounds takes 30
seconds to complete, the rest interval between sets would
be 300 seconds or 5 minutes.17 Without allowing for this
proper rest interval, muscles may become over fatigued
which may lead to poor technique which may result in
injury.
A study performed by Luebbers and Potteiger focused on
the importance of recovery time following a plyometric
program. In the study, neither group showed an improvement
immediately post training. However, when the subjects were
allowed four weeks to recover, the study showed obvious
effects that recovery can have on performance. It remains
unclear if the results would have increased more with a
longer recovery. What is clear however is that a recovery
period should be included following a plyometric training
program.17
Along with recovery, detraining effects can occur
after a training program. Detraining may occur when an
athlete reduces the training intensity, during, or ceases
to train due to injury or illness.18-19 Detraining can result
in the loss of anatomical and physiological adaptations as

38
well as decrease performance.18-19 The amount of detraining
depends on the length of time and the training level of the
athlete.14
A study performed by Faigenbaum et al demonstrated a
very rapid and significant decrease in strength of
preadolescence kids who trained for 8 weeks and were
reevaluated 8 week after the training had ended.18-19 A study
performed by Kraemer et al2. investigated whether the was
any change in vertical jump height after detraining
occurred. The study showed that although there was no
difference in jump height after 2 weeks, there was a
reduction of 3-5% after 12 weeks.2
To help avoid detraining, athletes should often
consider other methods of training. Although the exact
mechanism for detraining is still not known, it is likely
that changes in neuromuscular functioning are partially
responsible.20

Plyometric Training Effects on the Lower Extremity
As mentioned earlier, plyometic training has many
benefits that can help maximize athletic performance.
Studies focusing on the benefits of plyometric training
have found that this type of exercise can increase muscular
power output, regulate lower extremity muscle co-

39
activation, and correct poor mechanics of the knee, ankle
and hip.2,9,11
One of plyometric exercises known advantages is
increasing muscle output. A recent study by Potteiger et
al. examined changes in muscular power output and fiber
characteristics following a 3 day a week, 8 week plyometric
and aerobic exercise program in 19 physically active men.
The plyometric training consisted of vertical jumping,
bounding, and depth jumping. Muscle biopsies were collected
from the vastus lateralis before and after training and
type I and II fibers were identified.

Peak muscle power

output, measured using vertical jump significantly
increased in both groups. The authors reported this may be
in part to the reduced amortization phase between
concentric and eccentric movements. A reduced amortization
phase allows for greater increase power production. The
study showed an increase of power output that may be
related to an increase in muscle fiber size.11
Similar studies show supportive evidence of the
effects of an 8 week training program.12 Another common
theory of plyometric training is it may increase changes in
speed and explosive power. Over a course of 8 weeks Lehnert
et al. examined muscle power and locomotor speed was
before, during, and after a workout performed by youth

40
female volleyball players was complete. The individual’s
levels were measured by the standing vertical jump test,
vertical jump with an approach, and a 6x6 shuttle. The
results of the program supported the theory that plyometric
exercises are effective in increasing explosive power and
speed in young female athletes.12
Muscle co-activation has been shown to enhance
neuromuscular performance and prevent knee injuries by
increasing dynamic stability.9 The objective of a study
performed by Chimera et al. was to evaluate the effects of
plyometric training on muscle activation strategies and
performance of the lower extremity during jumping
exercises.

The subjects included in the study were

Division 1 female college athletes. Female athletes are
thought to have a greater risk of knee injury due to high
adduction and abduction knee movements and increased
landing force when compared to males. The participants
performed plyometric exercises 2 times per week for 6
weeks.

Surface electromyography was used to assess

preparatory and reactive activity of the vastus medialis
and vastus lateralis along with the medial and lateral
hamstring and hip abductors and adductors.

The results

concluded that after the six week plyometric exercise,
there were significant increases in firing of adductor

41
muscles during the preparatory phase.

It was also

concluded an increases in preparatory adductor to abductor
muscle coactivation, and an increase in quadriceps to
hamstring muscle coactivation.
Plyometric training induced beneficial neuromuscular
adaptations in the hip adductor muscles that may assist
with knee stability. Adductor muscle preactivation and
adductor and abductor coactivation both increased after
plyometric training. These neuromuscular adaptations,
combined with previous kinematic and kinetic data strongly
support the use of plyometric training to enhance dynamic
restraint and functional stability at the knee joint.16
These studies concluded that an increase in preparatory
coactivation can be increased in plyometric training and
may help reduce the risk of knee injuries in females.9 One
of the more common knee injuries theorized to be a result
of poor muscle activation is non- contact ACL tears.
Non-contact ACL tears are especially common amongst
female athletes. Non- contact ACL injuries in particular
are often attributed to excessive knee valgus. Research
shows females often land from a jump with increased knee
valgus then males. It is believed that jump training with
plyometrics can help reduce knee valgus during landing
leading to a reduction of non-contact ACL tears in female

42
athletes. The purpose of a study performed by Harrington et
al.21 was to assess if a jump training program could have
similar effects to those studies previously reported.
Female athletes had their knee valgus angles assessed
during two landing tasks. This was done by a twodimensional frontal-plane projection angle of the knee. A
digital camera was set up two meters anterior to the
subjects knee.

The digital images were imported into a

digitizing software program (Quintic 4, Quintic Consultancy
Ltd., United Kingdom). The angle between the lines formed
between the markers at the anterior superior Iliac spine
and middle of the tibiofemoral joint and that formed from
the markers on the middle of the tibiofemoral joint to the
middle of the ankle mortise was recorded as the valgus
angle of the knee.

Two tests were performed in this study.

One was a drop jump and the other was a crossover hop.

The

jump training program lasted 4 weeks, 3 times a week.
After training, the results showed significant decrease in
knee valgus during landing from their pretest measures.21

Plyometric Training vs. Resistance Training

A popular training program for athletes, coaches, and
strength and conditioning specialists is resistance

43
training. Resistance training will often use free weights
or weight machines along with a slow controlled motion by
the individual. Studies such as those performed by Vissing
et al show plyometric training and traditional resistance
training show specific benifits.22 Vissing et al wanted to
compare changes in muscle strength, power, and morphology
induced by conventional strength training vs. plyometric
training of equal time and effort requirements in 16
healthy males.22 Those subjects who were in a conventional
strength training group performed incline leg press, knee
extension, hamstring curl. The plyometric group performed
hurdle jumps, countermovement jumps and drop jumps. After
12 weeks of respective training, results concluded both
conventional resistances training and plyometric training
can benefit individuals. Moreover, the study went on to
explain that both types of training increased gross muscle
size, whereas only traditional resistance training
increased cross-sectional area.
The study concluded that both traditional resistance
training and plyometric training had very similar gains in
muscle strength, whereas muscle power increased almost
exclusively in plyometric training.21 It is well documented
that plyometric training is the best way to increase an
individual’s ability to increase jump height.20 Enhancing

44
power performance allows an individual to rapidly
accelerate their body during a dynamic movement such as a
vertical jump. The increased power that leads to better
acceleration can only be increased by plyometric training
exercises.1,2,21
Brown et al also studied the different effects of
resistive training and plyometric training in female
dancers.23 The purpose of the study was to observe the
differences in performance found in female dancers who
participated in either plyometric or traditional weight
training.

The plyometric group performed 3 sets of 8

repetitions of 4 different lower body plyometric exercises
twice a week.

The weight training group performed 3 sets

of 6 to 8 repetitions of 4 lower body isotonic exercises
twice a week.

All subjects in the study performed testing

prior to and post the 6 week work outs.

The testing

included in this study consisted of assessments of jumping
skill and lower body strength and power.

Strength was

assessed via 3 one repetition max tests: using the leg
press, leg curl and leg extension.

Power was assessed with

a wingate anaerobic power test and vertical jump height
tests.

Aesthetic jumping ability was assessed using 1

dance faculty member.

The results showed there were no

differences in the jumping ability, strength or power among

45
the groups at the start of the study.

The plyometric group

significantly increased leg press strength, standing
vertical jump height, and aesthetic jump height.

The

weight training group significantly increased leg press,
leg curl, mean aerobic power, and aesthetic jump height.
Results showed that both weight training and plyometics
have positive effects on vertical jumping ability.22
These two studies demonstrate plyometrics are not
meant to be performed alone. They should be used along with
other training methods such as strength, flexibility, and
cardiovascular training. When plyometric drills are
combined with a resistance training program, vertical jump
performance appears to be enhanced to a significantly
greater extent than if each of the training programs were
performed alone.24

Coaches Knowledge of Plyometric Exercise

Recent studies and current literature prove plyometic
exercise can increase athletic performance and decrease the
risk of injury. What is not understood is why coaches may
or may not have athletes perform plyometrics. Factors such
as time, commitment, knowledge of plyometrics, or sports
they coach may be factors. Although no current literature

46
has focused on coachs’ knowledge of plyometric exercise, an
emphasis of coaches’ knowledge of concussions has been a
recent topic. Although these two topics are not directly
related, coaches’ knowledge may be reasons why they do not
have their athletes perform plyometric exercise.
Many studies have focused on coach’s knowledge and
management of sport related concussions. Studies have shown
that coaches main weakness is that they believe all
concussions may be treated the same.25 This may be an
indication that high school coaches understand the basics
of a concussion but are unsure of how to follow up and
manage an athlete with symptoms. These results may indicate
that high school coaches may readily recognize concussion
symptoms, and thus more attention may need to be given to
educating coaches on the management of concussions to
ensure they are equally confident in recognizing and
treating concussive injuries in their athletes.25
Much like concussions, plyometric exercise also
involves knowledge of many different domains of exercise.
If coaches do not have the knowledge of the principles of
plyometric exercise, they may either not feel confident in
their ability to run plyometric exercises for their
athletes or may be performing them incorrectly which could
lead to injury.

47

Summary

Explosive power production is essential for maximal
performance in many athletic events.1 Plyometric exercises
are defined as eccentric loading immediately followed by a
concentric contraction.9 Research has shown that plyometric
training can increase maximal power output and also
increase vertical jump height.
One of plyometric exercises most significant
advantages is increasing muscle output. An increase in
muscle output leads to greater power generated. Peak muscle
power output, measured using a vertical jump significantly
increased in groups performing plyometric exercise. This
may be in part to the reduced amortization phase between
concentric and eccentric movements. A reduced amortization
phase allows for greater increase power production. An
increase in power production may possibly be directly
related to an increase in muscle fiber size and muscle
output.11
The overall goal of plyometric training is to increase
power output for individuals to increase jump height and
maximize power.

In studies performed showing gains in

48
athletes performing traditional weight lifting vs.
plyometric exercise, it is well documented plyometric
training is the best way to increase an individual’s
ability to increase jump height and maximal power.20
Plyometric training is an established technique that
can be used to maximize athletic performance such as
maximal power output and jumping ability as well as
facilitate positive neuromuscular control to reduce injury
and correct faulty jumping or cutting mechanics.

49

APPENDIX B
The Problem

50
STATEMENT OF THE PROBLEM

One of the primary training goals of plyometric
exercises is to increase the maximal power output and
jumping ability. Using plyometric training in a safe and
correct manner has shown to produce multiple positive
results such as improving explosive power, increasing
vertical jump height, and agility, and developing faster
contraction times with both slow and fast twitch muscle
fibers.4 Additionally, ploymetric exercise may lead to a
decrease of lower extremity injuries.

Coaches may be aware

of plyometrics and how they can be used to help benefit
athletes, but may not have the knowledge to perform them
safely and effectively implement into their respective team
workouts. Multiple training programs are easily available
to high school coaches, but the extent of what they know
about performing this type of exercise is still widely
unknown. The purpose of this study is to determine coaches’
level of knowledge when incorporating plyometric exercise
training programs into their practices and conditioning.

51

Definition of Terms
The following definitions of terms are as defined for
this study:
1.

Concentric- A muscle contraction in which the muscle
fibers pull together and shorten.4

2.

Eccentric- A muscle contraction, which occurs when the
muscle lengthens under tension.4

3.

Myofibrils- Contractile structures composed of
myofilaments.4

4.

Golgi Tendon Organs-Receptors that are activated by
stretch or active contraction of a muscle and that
transmit information about muscle tension.4

7.

Plyometrics- A type of exercise training designed to
produce fast, powerful movements, and improve the
functions of the nervous system, generally for the
purpose of improving performance in sports.

8.

Stretch shortening cycle- where the muscles involved
are first stretched rapidly and then shortened to
accelerate the body or limb.10

52

Basic Assumptions
The following are basic assumptions of this study:
1.

The subjects of this study will complete the survey to
the best of their ability.

2.

The survey provided was valid and reliable.

3.

Subjects did not use any outside resources to complete
the survey.

4.

Responses and demographic questions will be varied.

Limitations of the Study
The following are possible limitations of the study:
1.

The results of the study are only valid for high
school coaches in the state of Pennsylvania, results
for other states cannot be generalized.

2.

Coaches may choose to not respond to the online
survey.

3.

Athletic Directors will be responsible to forward the
survey to their high school coaches.

4.

Coaches may not have access to online survey.

5.

Coaches may quit taking the survey at any time.

6.

Time between survey validity was only 2 weeks.

53

Significance of the Study
It is vital that those who are training high school
athletes understand the concept of plyometric exercise.
Plyometric exercise gives athletes the opportunity to
increase vertical jump height, maximal power output, and
agility. If done incorrectly, this type of exercise can
lead to improper mechanics or even injury. The results of
this study may help identify knowledge of plyometric
training among coaches at the high school level. The
overall goal is to identify areas of the knowledge of
plyometrics.

54

APPENDIX C
Additional Methods

55

APPENDIX C1
High School Coaches’ Knowledge of Plyometic Exercise Survey

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APPENDIX C2
Institutional Review Board –
California University of Pennsylvania

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Institutional Review Board
California University of Pennsylvania
Morgan Hall, Room 310
250 University Avenue
California, PA 15419
instreviewboard@calu.edu
Robert Skwarecki, Ph.D., CCC-SLP,Chair

Dear Paul Rucci:
Please consider this email as official notification that your proposal titled
"Knowledge of Plyometric Exercises amongst High School Coaches”
(Proposal #11-041) has been approved by the California University of
Pennsylvania Institutional Review Board as amended.

(1)

(2)
(3)
(4)

The effective date of the approval is 2-02-2012 and the expiration date is 201-2013. These dates must appear on the consent form .
Please note that Federal Policy requires that you notify the IRB promptly
regarding any of the following:
Any additions or changes in procedures you might wish for your study
(additions or changes must be approved by the IRB before they are
implemented)
Any events that affect the safety or well-being of subjects
Any modifications of your study or other responses that are necessitated
by any events reported in (2).
To continue your research beyond the approval expiration date of 2-012013 you must file additional information to be considered for continuing
review. Please contact instreviewboard@calu.edu
Please notify the Board when data collection is complete.
Regards,
Robert Skwarecki, Ph.D., CCC-SLP
Chair, Institutional Review Board

75

APPENDIX C3
COVER LETTER

76

Dear High School Coach:
My name is Paul Rucci and I am currently a graduate student at California University of
Pennsylvania pursing a Master of Science degree in Athletic Training. Part of the
graduate study curriculum is to complete a research thesis through research and I am
conducting survey research to determine high school coaches’ knowledge of plyometric
exercise.
High school coaches in the state of Pennsylvania are being asked to participate in this
research; however, your participation is voluntary and you do have the right to choose not
to participate. You also have the right to discontinue participation at any time during the
survey completion process at which time your data will be discarded. The California
University of Pennsylvania Institutional Review Board has reviewed and approved this
project. The approval is effective 02/02/2012 and expires 02/02/2013
Data will be collected online via surveymonkey and will be kept confidential and
anonymous. Informed consent to use the data collected will be assumed upon return of
the survey. Aggregate survey responses will be housed in a password protected file on the
CalU campus. Minimal risk is posed by participating as a subject in this study. I ask that
you please take this survey at your earliest convenience as it will take approximately 20
minutes to complete. If you have any questions regarding this project, please feel free to
contact the primary researcher, Paul Rucci at RUC6286@calu.edu or by phone at (207)
944-4809. You can also contact the faculty advisor for this research Shelly DisCesaro at
dicesaro@calu.edu. Thank you in advance for your participation. Please click the
following link to access the survey (https://www.surveymonkey.com/s/LLCQ75C )
Again, thank you for taking the time to take part in my thesis research. I greatly
appreciate your time and effort put into this task. The survey can be found at
https://www.surveymonkey.com/s/LLCQ75C
Sincerely,
Paul Rucci, ATC
Primary Researcher
California University of Pennsylvania
250 University Ave
California, PA 15419
(207) 944-4809
RUC6286@calu.edu

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APPENDIX C4
REFERENCES

78

REFERENCES
1.

Plowman S, & Smith. Exercise physiology. Baltimore:
Lippincott Williams&Wilkins;2009:525-526.

2.

Kraemer W, Ratamess N, Volek J, et al. Detraining
produces minimal changes in physical performance and
hormonal variables in recreationally strength-trained
men. J Strength Conditioning Research.2002;16:373-382.

3.

Bompa T, Carrera M. Periodization training for sports
(2nd ed.). Champaign, IL: Human Kinetics;2005

4.

Boyle M. Functional training for sports. Champaign,
IL: Human Kinetics;2004

5.

Chu D. A. Jumping into plyometrics. Champaign, IL:
Human Kinetics;1998

6.

Gambetta V. Plyometrics – myths and
Sport Coach.1999;20:7-12

7.

Potach D H, Chu D A. Plyometric training. In R. T.
Beachle & R. W. Earle (Eds.), Essentials of strength
training and conditioning;2004

8.

Zatsiorsky M, & Kraemer W J. Science and practice of
strength training. Champaign, IL: Human Kinetics;2006

9.

Chimera N, Swanik K, Swanik T, et al. Effects of
Plyometric Training on Muscle Activation Strategies
and Performance in Female Athletes. Journal of
Athletic Training.2004;39:24-34. Accessed June 24,
2011

10.

Makaruk H, Sacewicz T. Effects of Plyometric Training
on
Maximal Power Output and Jumping Ability. Human
Movement.2006;11:17-27.Accessed June 21,2004

11.

Potteiger J, Lockwood R, Haub M, et al. Muscle Power
and Fiber Characteristics Following 8 Weeks of

misconceptions.

79
Plyometric Training. Journal of Strength and
Conditioning. 1999;13:274-279.Accessed June 30, 2011
12.

Lehnert M, Lamrova I, Elfmark M. Changes in speed and
strength in Female Volleyball Players Before and After
Plyometric Training Programs;2006

13.

McClellan T. Big jumps. Training and Conditioning.
March 2005;42-46.

14.

Potach DH, Chu DA. Plyometric Training.Essentials of
Strength Training and Conditioning. TR Beachle and RW
Earle (eds). Champaign,Il: Human Kinetics.

15.

Stemm J, Jacobson B. Comparison of Land and AquaticBased Plyometric Training on Vertical Jump
Performance. Journal of Strength and
Conditioning.2007;21:568-571.Accessed June, 19, 2011

16.

National Strength and Conditioning Association.
Position statement: Explosive/plyometric exercise.
NSCA.J;1993:16

17.

Luebbers PE, Potteiger JA, Hulver MW, et al. Effects
of plyometric training and recovery on vertical jump
performance and anaerobic power. J Strength
Conditioning.2004;17:704-9.

18.

Faigenbaum A, Wescott W, Micheli L, Outerbride R,
Long, LaRosa-Loud R, Zaichkowsky L. The effects of
strength training and detraining on children. J
Strength Conditioning. 1996;10:109-114

19.

Benjamin H, Glow K. Strength training for children
and adolescents. The Physican and
Sportsmedicine.2003;9:220-225.

20.

Baechle T, Earle R. Essentials of strength training
and conditioning. National Strength and Conditioning
Association: Human Kinetics;2000.

21.

Harrington L. The Effects of 4 Weeks of Jump Training
on Landing Knee Valgus and Grossover Hop Performance
in Female Basketball Players. Journal of Strength and
Conditioning.2010;24:3427-3432.
http://web.ebscohost.com/ehost/detail?vid=3&hid=19&sid
=e17a92a6-8880-410f. Accessed June 30,2011

80

22.

Vissing K, Brin M. Lonbro, et al. Muscle adaptations
to plyometric vs. resistance training in untrained
young men. Journal of Strength and
Conditioning.2008;22:1799-1810.

23.

Brown A, Wells T. Schade, M., et al. Effects of
Plyometric Training Versus Traditional Weight Training
on Strength, Power, and Aesthetic Jumping Ability in
Female Collegiate Dancers. Journal of Dance Medicine
and Science.2007;11:38-44.Accessed June 22, 2011

24.

Chu D. Jumping into Plyometrics. 2nd ed.Champaign,
III: Human Kinetics. 1998.

25.

Guilmette T, Malia L, McQuiggan M. High school coaches
knowledge of sport related concussion. Brain Injury.
2007;21:1039-1047.Accessed June 22, 2011

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ABSTRACT
Title: High School Coaches’ Knowledge of Plyometric
Exercise
Researcher: Paul Rucci
Advisor: Dr. Shelly DiCesaro
Research Type: Master’s Thesis
Context: In light of the economic crisis Pennsylvania
school are facing, budgets do not normally afford strength
and conditioning coaches. Therefore, high school coaches
may often be leading conditioning programs, including
plyometric exercise for their athletes. However, it is
unknown if coaches actually do include plyometric programs
into their practice or if they have the proper knowledge of
plyometrics to implement them in a safe and effective
manner.
Objective: The purpose of this study was to identify high
school coaches in Pennsylvania that use plyometric
exercises as part of their workouts for high school
athletes and gain a better understanding of their level of
knowledge with this type of training.
Design: Descriptive research study
Setting: The survey was distribute via email to high school
coaches in the state of Pennsylvania
Subjects: High school coaches from the state of
Pennsylvania in the PIAA were surveyed for this study.
Interventions: The independent variables for this study
were 1) high school coaches’ gender, 2) high school
coaches’ gender of sport they coach, and 3) high school
coaches’ age group. This survey was conducted via an online
survey program. The survey was distributed to high school
athletic directors in the PIAA who in turn, forwarded the
survey link to their coaches’. The survey was open for 4
weeks with a reminder email sent at 2 weeks into the
survey.
Measurements: All data was analyzed via SPSS version 18
with an alpha level of 0.05 Coaches gender and sport gender

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coached was evaluated via a one way independent t-test.
High school coach’s age group was evaluated utilizing an
ANOVA.
Results: P-values of the first two interventions were
p=.188, and p=.170 respectively showing no sign of
significance. The significance found in the 3rd
intervention, p=.976 was also not significant.
Conclusion: Although no significance was found in the
study, it is worth noting that coaches scored A mean o f6
out of 20 answers correctly in the survey. This may
indicate that coaches need to be educated regarding
plyometric exercise and implementation into daily
practices.