The Effect of Dynamic and Static Stretching onPerformance

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

byJaclyn C. Oakley

Research Adviser, Dr. Ben Reuter

California, Pennsylvania2007

ii

iii

ACKNOWLEDGEMENTS

I would like to take this opportunity to thank the

many people who made this thesis a success. First and

foremost, I would like to thank my parents for always

believing in me and encouraging me to strive to reach my

goals. Without their unconditional love and support, I

would not be where I am today. I also want to thank my

sisters for being my best friends; Jill for being like a

second mother to me, Jen for all the laughs and memories,

and Jess, the best listener I know. I also want to thank

my fifth sister, Lauren, who has been my best friend

since the second grade. She has been there for me

through the good times and the bad, and I am so lucky to

have her in my life.

Next I would like to thank my committee members Dr.

Reuter, Dr. Hess, and Dr. Kinsey, for all of their help

this year. I want to especially thank Dr. Reuter for

pushing me to excel in every aspect of this thesis.

Without his knowledge and high expectations, this would

not have been possible. I would also like to thank Dr.

Hess for her dedication and encouragement, and Dr. Kinsey

for his statistical expertise.

iv

A huge thank you also goes out to Mark and Mike

Lesako, who are two of the most amazing people I have

ever met. They helped me in every way with the

organization of this study, making it as easy as possible

for me to carry out. I am incredibly lucky to have

gotten the chance to work along side them at W&J, and owe

them so much for so many reasons. Mike and Mark; I had a

blast with you this year, and I hope our friendship

continues for years to come.

Lastly, I would like to thank the other graduate

students as well as the underclassmen who have become

like a family to me this year. From the time we all met

back in the summer, we grew so close, and I would never

have made it through this year without their support.

Phylissa, you have been a great friend to me throughout

our four years at King’s, and I am so glad we could

continue our education together for graduate school. I

know you will excel in your Doctorate program, and will

miss you so much. Aimee, you have been there for me in

every way possible this year, and I value our friendship

so much. Mitch, thank you for generously sacrificing

your time to help me when I was in need. To all my

classmates; thanks for all the memories, and for making

this year such a great one.

v

TABLE OF CONTENTS

Page

SIGNATURE PAGE . . . . . . . . . . . . . . ii

ACKNOWLEDGEMENTS . . . . . . . . . . . . . iii

TABLE OF CONTENTS . . . . . . . . . . . . . v

LIST OF TABLES . . . . . . . . . . . . . . vii

LIST OF FIGURES . . . . . . . . . . . . . . . . . viii

INTRODUCTION . . . . . . . . . . . . . . . . 1

METHODS . . . . . . . . . . . . . . . . . 6

Research Design. . . . . . . . . . . . . . 6

Subjects. . . . . . . . . . . . . . . . . . 7

Instrumentation . . . . . . . . . . . . . 7

Procedures . . . . . . . . . . . . . . . . .9

Hypotheses . . . . . . . . . . . . . . . 12

Data Analysis . . . . . . . . . . . . . . 12

RESULTS . . . . . . . . . . . . . . . . . . 13

Hypotheses Testing . . . . . . . . . . . . 13

DISCUSSION . . . . . . . . . . . . . . . . 17

Discussion of Results . . . . . . . . . . . 18

Conclusions . . . . . . . . . . . . . . . 21

Recommendations . . . . . . . . . . . . . . . 22

REFERENCES . . . . . . . . . . . . . . . . 24

APPENDICES . . . . . . . . . . . . . . . . . . . . . 27

A. Review of the Literature . . . . . . . . . . . 28

vi

Stretching and Flexibility . . . . . . . . 29

Mechanisms of Stretching . . . . . . . . . . 29

Stretching Techniques . . . . . . . . . . . 31

Stretching and Power . . . . . . . . . . . . . 34

Stretching and Performance . . . . . . . . . . 36

Stretching and Injury Risk . . . . . . . . . . 41

Summary . . . . . . . . . . . . . . . . 43

B. The Problem . . . . . . . . . . . . . . 47

Statement of the Problem . . . . . . . . . 47

Definition of Terms . . . . . . . . . . . 48

Basic Assumptions . . . . . . . . . . . . 50

Limitations of the Study . . . . . . . . . 51

Significance of the Study . . . . . . . . 51

C. Additional Methods. . . . . . . . . . . . 54

Informed Consent (C1) . . . . . . . . . . .55

Functional Testing and Equipment (C2) . . . . 59

Stretching Protocols (C3) . . . . . . . . . . 62

Institutional Review Board (C4) . . . . . . .67

Athletic Director Consent Form (C5) . . . . . 74

Data Collection Sheets (C6). . . . . . . . . . 76

REFERENCES . . . . . . . . . . . . . . . 79

ABSTRACT . . . . . . . . . . . . . . . . 83

vii

LIST OF TABLES

1. 2 X 3 repeated measures ANOVA for test (2)by condition (3) for effect of stretchingconditions on the T-test for agility. The typeof stretching condition had a significanteffect (.008) . . . . . . . . . . . . . . . . . . 15

2. Means and Standard Deviations for the T-testFor agility times according to the stretchingCondition . . . . . . . . . . . . . . . . . . . . 16

3. Paired t-test for the means and standarddeviations for static stretching and dynamicstretching (Pair 1), dynamic stretching and thecontrol Pair 2), and static stretching and thecontrol (Pair 3) . . . . . . . . . . . . . . . . . 16

4. Paired t-test for the differences betweenStatic for static stretching and dynamicstretching (Pair 1), dynamic stretching and thecontrol Pair 2), and static stretching and thecontrol (Pair 3) . . . . . . . . . . . . . . . . . 16

viii

LIST OF FIGURES

1. Mean T-test for agility times of theStretching conditions(3) with the interactionOf tests(2) . . . . . . . . . . . . . . . . . . . . 17

INTRODUCTION

Stretching and flexibility training have been very

common among the athletic population, making up a large

part of training programs as well as pre-event warm-up

activities for athletes.1-15 Flexibility refers to the

musculotendinous unit’s ability to elongate with the

application of a stretching force, determining the range

of motion of a joint.1,2 Therefore, the act of stretching

can be defined as movement applied by an external or

internal force in order to increase muscle flexibility

and/or joint range of motion.3

It has been theorized by athletes, coaches, and

athletic trainers that increasing flexibility is an

important aspect of physical fitness, leading to an

increase in athletic performance as well as reducing the

incidence of injury.3,13,14,16,17-19,22 However, recent

research has found that the acute effects of stretching

may have negative results on both performance and risk of

injury.2-19 Studies have shown that static stretching

before competition may lead to musculoskeletal injury

rather than preventing injuries from occurring. The

result of increased flexibility due to stretching may be

attributed to a decrease in joint stability making

2

athletes more prone to injury.8,18 In addition to this

increased risk of injury, it has also been found that

stretching before participation may cause a decrease in

muscle strength, power output, and sprint

performance.3,8,13

In relation to strength and power, results in a

study by Papadopoulos et al20 examined the effects of

static and dynamic stretching on strength. The static

stretching consisted of an active hamstring stretch and

an active quadriceps stretch on the test leg each held

for 30s. Torque (the ability of a force to cause

movement) was used as a measure of strength, and results

showed a significant difference following the two

different stretching techniques.1,20 Torque was

significantly reduced with the static stretching

exercises, while no effect was seen when preceded with

the dynamic stretching exercises.20 A similar study by

Fowles et al6 found that when looking at the torque of

the plantar flexor muscles, the strength was reduced by

30% immediately after a static stretching regimen.

Torque was still reduced by nine percent 60 minutes after

the stretching took place. This length of time shows that

pre-exercise stretching negatively affects peak torque up

to at least 60 minutes. Nelson et al17 also reported that

3

when knee flexion lift exercises were performed (in which

the knee is flexed in a prone position) at 60% or 40% of

body weight, static stretching significantly reduced

strength. These studies are all in agreement with one

another indicating that static stretching negatively

affects strength production.

The recent literature concerning static stretching

has reported a negative effect on sport performance.

This is a growing concern among sports professionals,

encouraging them to learn more about the most effective

warm-up methods to positively benefit performance. The

results in many of these studies have been dynamic

stretching.

In a study by Fletcher8 comparing the effect of

static and dynamic stretch protocols on a 20 meter sprint

performance, it was found that the groups participating

in the static stretching warm-up had a significant

increase in their sprint time, and the dynamic stretching

groups had a significant decrease in their sprint times.8

Similarly, in a study by Siatras et al21 examining

gymnasts’ vaulting speeds, it was found that vault speeds

were significantly decreased following static stretching

exercises.

4

In contrast, Little and Williams22 found static

stretching not to be detrimental to high speed

performance including vertical jump, 10m sprint, 20m

sprint, and a zig-zag agility test. However, dynamic

stretching was found to be the most effective as a warm-

up for performance producing significantly faster sprint

times. Dynamic stretching was also found to be the most

effective stretching technique in a study by McMillian et

al,9 revealing better performance scores in the T-shuttle

run, medicine ball throw, and the 5-step jump as compared

to static stretching and no stretching.

In two very similar studies looking at adolescents,

both conducted by Faigenbaum et al, (10,11) results showed

that pre-event dynamic stretching alone or in conjunction

with static stretching is more beneficial than static

stretching alone. However, it is important to realize

that the subjects used in these studies were adolescents,

which could produce different results when compared to

adults, due to the fact that adolescents are still

growing.

Although there is still some contradictory evidence

regarding static and dynamic stretching, the majority of

recent literature indicates that static stretching may be

detrimental to an athlete’s performance. These studies

5

seem to be in favor of dynamic stretching, which has

shown to be much more beneficial.2-19 Results have led to

a great deal of interest from the athletic professionals,

who are beginning to move away from the traditional

method of static stretching, and incorporate dynamic

stretching into their warm-up routines.8-10,22

This study will attempt to answer the following question:

1)How do the treatments of dynamic stretching, static

stretching, and no stretching affect the performance on

the T-test for agility?

6

METHODS

The methods section will serve to give an overview

as to how the experiment was conducted. It will include

sections dedicated to Research Design, Subjects,

Instrumentation, Procedures, Hypotheses, and Data

Analysis.

Research Design

A quasi-experimental design, in which the subjects

were each serving as their own control, was used for this

study. All subjects were volunteers; and were not

randomly selected. The independent variable was the

stretching protocol used (dynamic stretching warm-up

protocol, static stretching warm-up protocol, and no

stretching). The dependent variable was the time on the

T-test for agility. The strengths of the study were that

the population was already known (Division III football

players) and a sample was taken from that particular

population. In addition, the study is a within subjects

design in which each subject served as their own control.

Limitations of this study are that the results can only

be generalized to Division III football players, the

subjects were volunteers, and that the same person served

7

as the researcher, the data collector and the Athletic

Trainer.

Subjects

The subjects in this study consisted of 18 male

Division III football players (n=18). All subjects were

between the ages of 18 and 23 years, and had not

sustained a lower extremity injury within the past six

months. The volunteers were chosen by a sample of

convenience, with no influence from the coaching staff.

The subjects were screened for previous history of lower

extremity injuries, and those who have had these injuries

in the past six months were excluded from volunteering.

Each subject completed an Informed Consent (Appendix C1)

before participating in the study. No names were included

in the study.

Instrumentation

The testing instruments that were used in this study

were the T-test for agility, and the Speed Trap II timing

system. The Speed Trap II TimerTM (Appendix C2) is a

timing system that starts timing when pressure is

released from the starting pad, and stops when the

8

athlete crosses the reflective beam at the finish line.

The times are recorded on the clock that sits on top of

the beam.23 This timing system is accurate to 1/100th of a

second, and is capable of timing an athlete up to 55

yards accurately.23 This piece of equipment was used to

measure the velocity of the athletes’ T-test for agility,

testing agility.

The T-test for agility (Appendix C2) is a valid and

reliable test to measure agility requiring the athlete to

sprint forward, laterally, and backward as quickly as

possible.24 The subject sprints forward first, then

shuffles laterally to one side, then the other (without

crossing over their feet), and then backward. This test

was done in the Henry Gymnasium at Washington and

Jefferson College. The athletes performed this test on

the hard wood gym floor. Their attire included a T-

shirt, mesh shorts, and running sneakers. The T-test for

agility was scored using the time recorded from the Speed

Trap II TimerTM. The Speed Trap II TimerTM was used to

measure the velocity in seconds of each athlete to

determine how quickly the athlete completed the T-test

for agility. The T-test for agility is used to measure

leg speed as well as leg power and agility.24

Procedures

9

The study was approved by the California University

of Pennsylvania Institutional Review Board (IRB)

(Appendix C4). The researcher also obtained permission

to use Washington and Jefferson College (NCAA Division

III) athletes from the Washington and Jefferson Athletic

Director (see letter, Appendix C5). A random sample of

volunteer subjects were obtained who had not sustained a

lower extremity injury in the past six months. Prior to

the subjects’ involvement in the study, the researcher

explained the concept of the study and everything it

entailed to each subject in a meeting that was held prior

to the first testing date. At this time the Informed

Consent Form (Appendix C1) was administered explaining

the procedure and need for the study as well as the risks

involved.

Each subject was informed they would be tested on

six separate days with 48 hours separating each testing

session. Each subject was assigned a time slot so that

only one subject was participating at a time. Each

stretching protocol was performed twice. On each of the

testing days, the subjects’ were randomly assigned to one

of the stretching protocols; dynamic stretching, static

stretching, or no stretching by picking a S,D, or C out

of a hat. Once a subject did a certain protocol twice,

that piece of paper was no longer included in the pool.

10

On testing day, all subjects performed a standard 5

minute jog warm-up at their own pace before any

stretching or testing. After the warm-up, subjects

rested for two minutes. Immediately after the two

minutes of rest, subjects were asked to perform their

randomly assigned protocol.

The active dynamic warm-up stretching protocol(ADWS)

(Appendix C4) that was used included: high knees

(gluteals and hamstrings), drop lunges (gluteals and hip

flexors), flick backs (quadriceps and hip flexors)

lateral shuffles (adductors and abductors), and heel to

toe walks (gastroc and soleus).8,9 Subjects performed 20

repetitions of each of these dynamic stretches on each

leg, walking back after each one.

The active static warm-up stretch protocol (ASWS)

(Appendix C4) that was used consisted of a gluteal

stretch, hip flexor stretch, hamstring stretch,

quadriceps stretch, adductor stretch, abductor stretch,

and a gastroc/soleus stretch, with the stretches being

held for 20 seconds each bilaterally.8 The dynamic and

static stretches were carefully chosen to correspond with

one another so that the same muscles were being stretched

for the same amount of time. The researcher recognized

that there are eight static stretches and five dynamic

stretches, but it should be noted that the static

11

stretches are single joint motions, whereas the dynamic

stretches are multi-joint motions.

The researcher had a tape recording prepared that

instructed the subjects when to change the stretch to

ensure that the stretching was consistent. For the

control trial, the subjects rested the same amount of

time it took to complete the protocols. After the

subjects were finished with the assigned protocol, they

had another rest period of two minutes to prepare for

their performance test. They then performed two trials

of the T-test for agility with a one minute rest in

between trials. The two times were timed using the Speed

Trap II timing system, and the best time of the two

trials were recorded. The results were recorded on the

data collection forms (Appendix C6). This process was

repeated until the subjects performed each of the

protocols twice, to ensure a true repeated measures

design.

12

Hypotheses

The following hypotheses were based on the literature

reviewed and the information investigated when developing

this study.

H0) There will not be a significant difference in T-

test for agility time between the subjects performing

a static stretching protocol, dynamic stretching

protocol, or a no stretching protocol.

HA) There will be a significant difference in T-test

for agility time between the subjects performing a

static stretching protocol, dynamic stretching

protocol, or a no stretching protocol.

Data Analysis

All data was analyzed using SPSS version 14.0 for

Windows, with a .05 alpha level. Scores for each group

on the dependent variable, the T-test for agility, were

used. The research hypothesis was analyzed using a 2 X 3

repeated measures ANOVA for test (2) by condition (3).

13

Results

The purpose of this study was to examine the

differences between three stretching protocols (static

stretching, dynamic stretching, and no stretching) on the

performance of the T-test for agility in Division III

collegiate football players. The following section

contains the data collected throughout the study.

Hypothesis Testing

The following hypotheses were tested in this study.

All hypotheses were tested with the level of significance

set at ≤.05. A 2 X 3 repeated measures ANOVA for test

(2) by condition (3) was calculated comparing the time on

the T-test for agility for subjects on three different

stretching conditions: static stretching, dynamic

stretching, and no stretching. A significant effect was

found (F(2,34)= 5.518, p < .001. Follow-up protected t

tests revealed that times were significantly different

between static stretching (11.28±1.21 sec) and dynamic

stretching (10.99±1.15 sec), and between dynamic

stretching (10.99±1.15 sec) and the control (11.47±1.08

sec). The pairs used in the paired t-test statistics

14

were chosen by picking the best time of the two tests for

each condition. The T-test for agility times were found

to be significantly influenced by stretching.

Hypothesis 1 (H0): There will not be a significant

difference in T-test for agility time between the

subjects performing a static stretching protocol, dynamic

stretching protocol, and no stretching protocol.

Hypothesis 2 (HA): There will be a significant

difference in T-test for agility time between the

subjects performing a static stretching protocol, dynamic

stretching protocol, and no stretching protocol.

Conclusion: The null hypothesis was rejected. The

time on the T-test for agility was affected by the

stretching condition. The alternate hypothesis was

supported.

15

Table 1. 2 X 3 repeated measures ANOVA for test (2) bycondition (3) for effect of stretching conditions on theT-test for agility. The type of stretching conditionhad a significant effect (.008) on the T-test for agilitytime

Type IIISum of

Squares dfMean

Square F Sig.Test Sphericity

Assumed.313 1 .313 2.795 .113

Greenhouse-Geisser .313 1.000 .313 2.795 .113

Huynh-Feldt .313 1.000 .313 2.795 .113Lower-bound .313 1.000 .313 2.795 .113

Error(test) SphericityAssumed 1.901 17 .112

Greenhouse-Geisser 1.901 17.000 .112

Huynh-Feldt 1.901 17.000 .112Lower-bound 1.901 17.000 .112

Condition SphericityAssumed

.816 2 .408 5.518 .008

Greenhouse-Geisser .816 1.725 .473 5.518 .012

Huynh-Feldt .816 1.902 .429 5.518 .010Lower-bound .816 1.000 .816 5.518 .031

Error Condition SphericityAssumed 2.515 34 .074

Greenhouse-Geisser

2.515 29.333 .086

Huynh-Feldt 2.515 32.341 .078Lower-bound 2.515 17.000 .148

Test*Condition SphericityAssumed

3.037 2 1.519 21.236 .000

Greenhouse-Geisser 3.037 1.621 1.873 21.236 .000

Huynh-Feldt 3.037 1.768 1.718 21.236 .000Lower-bound 3.037 1.000 3.037 21.236 .000

Error(Test*Conditon)

SphericityAssumed 2.431 34 .072

Greenhouse-Geisser

2.431 27.562 .088

Huynh-Feldt 2.431 30.049 .081Lower-bound 2.431 17.000 .143

16

Table 2. Means and Standard Deviations for the T-test foragility times according to the stretching condition.

Mean Std. Deviation NSS1 11.3367 1.36953 18SS2 11.2800 1.21129 18DS1 11.0728 1.21397 18DS2 10.9978 1.14793 18C1 11.4722 1.08099 18C2 11.5422 1.13549 18

Table 3. Paired t-test for the means and standarddeviations for static stretching and dynamic stretching(Pair 1), dynamic stretching and the control (Pair 2),and static stretching and the control (Pair 3).

Mean N Std. Deviation Std. Error MeanPair 1 SS2 11.2800 18 1.21129 .28550

DS2 10.9978 18 1.14793 .27057Pair 2 DS2 10.9978 18 1.14793 .27057

C1 11.4722 18 1.08099 .25479Pair 3 SS2 11.2800 18 1.21129 .28550

C1 11.4722 18 1.08099 .25479

Table 4. Paired t-test for the differences between staticstretching and dynamic stretching (Pair 1), dynamicstretching and the control (Pair 2), and staticstretching and the control (Pair 3).

Paired Differences t dfSig

(2tailed)95%Confidence

Mean Std.Dev

Std. DevMean

Lower Upper

Pair 1 SS2 -DS2 .28222 .37905 .08934 .09373 .47072 3.159 17 .006

Pair 2 DS2 -C1

-.47444 .49712 .11717 -.72166 -

.22723 -4.049 17 .001

Pair 3 SS2 -C1

-.19222 .44764 .10551 -.41483 .03038 -1.822 17 .086

17

Figure 1. Mean T-test for agility times of the stretchingconditions(3) with the interaction of tests(2). Asignificant effect was found.

ControlDynamic StretchingStatic Stretching

condition

11.50

11.25

11.00

T-t

est

for

Ag

ility

Tim

e(s

ec)

21

Test

18

DISCUSSION

The following section is divided into three

subsections: Discussion of Results, Conclusions, and

Recommendations.

Discussion of Results

Stretching and flexibility training have been very

common among the athletic population, making up a large

part of training programs as well as pre-event warm-up

routines for athletes.1-15 It has been theorized by

athletes, coaches, and athletic trainers that increasing

flexibility is an important aspect of physical fitness,

leading to an increase in athletic performance as well as

reducing the incidence of injury.3,13,14,16,17-19,22 However,

recent research has found that the acute effects of

stretching may have negative results on both performance

and risk of injury.2-19 The focus of this study was to

compare static stretching, dynamic stetching, and no

stretching to see how each method affected the

performance on the T-test for agility in Division III

football players.

19

It was hypothesized that dynamic stretching would

yield faster times on the T-test for agility than static

stretching and no stretching. Performance of the T-test

for agility was measured using the Speed Trap II timing

system23. Statistical analysis revealed a significant

difference in performance between the three stretching

protocols.

Many of the subjects participating in the research

study also reported that the dynamic stretching protocol

was a better warm up and favor this type of stretching.

Some subjects also reported that they believed they were

faster after the dynamic stretching protocol.

The results of this study were similar to those

reported by Siatras et al21, Fletcher et al8, McMillian et

al9, and Little and Williams22. These studies all found

significant differences between the stretching

conditions. The study by Siatras et al, showed

significant increases in sprint time following static

stretching, however it was the only study showing no

effect following dynamic stretching.

It is important to note that all of the tests used

in these studies were anaerobic, all averaging under

twelve seconds. In the study by Fletcher8, the 20 meter

sprint was used with times averaging around three

20

seconds. Little and Williams22 used the 10 meter sprint

averaging two seconds, the flying 20 meter sprint

averaging 2.5 seconds, and the zig-zag agility test which

takes about 5 seconds to complete. Faigenbaum et al11

used the 10 meter sprint as well, and Siatras et al21

measured the vaulting speed from the start of the runway

until the contact with the vault, which is about 7.5

seconds. In this study, the T-test for agility took

about 10 seconds to complete; which is also a very short

time period. These findings support the fact that short

distance anaerobic events positively benefit from dynamic

stretching.

Vertical jump was also looked at in studies by

Little and Williams22, and Faigenbaum et al10,11, and

significant increases in height were found following

dynamic stretching. Other power tests such as the five

step jump and medicine ball throw were used in a study by

McMillian et al9, and were also found to improve

performance after dynamic stretching. These results show

that explosive power tests as well as short distance

anaerobic performance benefit from dynamic stretching as

compared to static stretching.

In regards to agility, only two studies, (Siatras et

al and McMillian et al) looking at how stretching affects

21

agility testing have been published, which is why the T-

test for agility was chosen for this particular study.

As mentioned earlier, Siatras et al21 found decreases in

the time on the zig-zag agility test following dynamic

stretching, but results were not found to be

statistically significant. Although Siatras et al did

not find significance, a significant effect was found in

the study by McMillian et al9. This is the only other

known study to use the T-test for agility.

A separate study by Faigenbaum et al10 found that the

shuttle run performance declined significantly after

static stretching as compared to dynamic stretching.

This shows that adolescents as well as adult athletes can

benefit from dynamic stretching.

CONCLUSIONS

This study revealed that the type of stretching

protocol (Static stretching, dynamic stretching, or no

stretching) had a significant effect on the time on the

T-test for agility in Division III collegiate football

players. The athletes in this study performed each

stretching protocol twice, followed by two trials of the

T-test for agility. Results showed that there was a

significant decrease in agility time when preceded with

22

dynamic stretching. In this case, knowing that dynamic

stretching positively benefited performance, it is

important to keep implementing dynamic stretching into

warm-up routines.

RECOMMENDATIONS

It is important for Certified Athletic Trainers to

be updated on the recent research regarding stretching to

be able to implement the most safe and beneficial warm-up

techniques for our athletes. The recent literature on

this topic is in favor of dynamic stretching, however,

there are still some aspects that need to be looked at

further. For example, the number of studies looking at

short distance sprint speed and studies looking at power

tests support the idea that dynamic stretching increases

performance. However, the studies looking at agility are

lacking, and therefore need to be further addressed to

ensure more consistency.

One recommendation for future research would be to

look at more than one agility test within a study instead

of just picking one. There are only a few studies using

agility tests, therefore, a study looking at a number of

agility tests would be beneficial. If similar results

23

are found, it would provide support for the agility

studies done previously.

Another recommendation would be to compare different

anaerobic and aerobic activities in terms of the time it

takes to complete them. As mentioned earlier there are

an abundance of studies looking at short distance events,

but very few, if any, on comparing short distance events

to endurance events. For example, it would be

interesting to compare dynamic and static stretching

looking at the mile run. If it is found that long

distance events positively benefit from dynamic

stretching, endurance athletes can benefit from this type

of stretching as well.

24

REFERENCES

1. Houglum PA. Therapeutic Exercise for AthleticInjuries. Champlain IL: Human Kinetics; 2001.

2. Thacker SB, Gilchrist J, Stroup DF, Kimsey DC. TheImpact if Stretching on Sports Injury Risk: ASystematic Review of the Literature. Med and Sciencein Sports Exercise. 2004;36:371-378.

3. Weerapong P, Hume PA, Kolt GS. Stretching:Mechanisms and Benefits for Sport Performance andInjury Prevention. Physical Therapy Reviews.2004;9:189-206.

4. Mann D, Whedon C. Functional Stretching:Implementing a Dynamic Stretching Program. AthleticTherapy Today. 2001;6:10-13.

5. Marek SM, Cramer JT, Fincher LA, et al. AcuteEffects of Static and Proprioceptive NeuromuscularFacilitation Stretching on Muscle Strength and PowerOutput. J. Athl. Train. 2005;4094-103.

6. Fowles JR, Sale DG. Time Course of Strength Deficitafter Maximal Passive Stretch Humans. Medicine andScience in Sports and Exercise. 1997;29:26.

7. Kokkonen J, Nelson AG, Cornwell A. Acute MuscleStretching Inhibits Maximal Strength Performance.Research Quarterly from Exercise and Sport.1998;69:411-415.

8. Fletcher IM. The Effect of Different Warm-upProtocols on 20 Meter Sprint Performance in TrainedRugby Players. J. Strength Cond. Res. 2004;18:885-888.

9. McMillian DJ, Moore JH, Hatler BS, Talor DC. Dynamicvs. Static-Stretching Warm Up: The Effect on Powerand Agility Performance. J. Strength Cond. Res.2006;20:492-499.

10. Faigenbaum AD, Bellucci M, Bernieri A, Bakker B,Hoorens K. Acute Effects of Different Warm-up

25

Protocols on Fitness Performance in Children. J.Strength Cond. Res. 2005;19:376-381.

11. Faigenbaum AD, Kang J, McFarland J, Bloom JM. AcuteEffects of Different Warm-Up Protocols on AnaerobicPerformance in Teenage Athletes. Pediatr Exerc Sci.2006;17:64-75.

12. Knudson DV, Noffal GJ, Bahamonde RE, Bauer JA.Blackwell JR. Stretching Has No Effect on TennisServe Performance. J. Strength Cond. Res.2004;18:654-656.

13. Nelson AG, Driscoll NM, Landin DK, Young MA,Schexayder IC. Acute Effects of Passive MuscleStretching on Sprint Performance. J. Sports Sci.2005;23:449-454.

14. Unick J, Kieffer SH, Cheesman W, Feeney A. The AcuteEffects of Static and Ballistic Stretching onVertical Jump Performance in Trained Women. J.Strength Cond. Res. 2005;19:206-212.

15. Lund H, Vestergaard-Poulsen P, Kanstrup IL, SejrsenP. The Effect of Passive Stretching on Delayed OnsetMuscle Soreness, and other Detrimental EffectsFollowing Eccentric Exercise. Scand. J. Med. Sci.Sports. 1998;8:216-221.

16. Haff GG. Roundtable Discussion: FlexibilityTraining. Strength Cond. J. 2006;28:64-85.

17. Nelson AG, Kokkonen J, Arnall DA. Acute MuscleStretching Inhibits Muscle Strength EndurancePerformance. J. Strength Cond. Res. 2005;19:338-343.

18. Church BJ, Wiggins MS, Moode MF, Crist R. Effect ofWarm-Up and Flexibility Treatments on Vertical JumpPerformance. J. Strength Cond. Res. 2001;15:332-336.

19. Witvrouw E, Mahieu N, Danneels L, McNair P.Stretching and Injury Prevention: An ObscureRelationship. Sports Med. 2004;34:443-449.

20. Papadopoulos G, Siatras T, Kellis S. The Effect ofStatic and Dynamic Stretching Exercises on theMaximal Isokinetic Strength of the Knee Extensors

26

and Flexors.Isokinetics and Exercise Science.2005;13:285-291.

21. Siatras T, Papadopoulos G, Mameletzi D, Kellis S.Static and Dynamic Acute Stretching Effect onGymnasts’ Speed in Vaulting. Pediatr Exerc Sci.2003;15:383-391.

22. Little T, Williams A. Effects of DifferentialStretching Protocols During Warm-ups on High-SpeedMotor Capacities in Professional Soccer Players. J.Sports Sci. 2004;22:589-590.

23. Brower Timings Systems. http://www.browertiming.com.Accessed October 22, 2006.

24. Pauole K, Madole J, Garhammer M, Rozenek.Reliability and Validity of the T-test for agilityas a measure of agility, leg power, and leg speed incollege-aged men and women. J.Strength Cond. Res.14:443-450. 2000.

27

APPENDIX A

Review of Literature

28

REVIEW OF THE LITERATURE

This review of literature will examine the effects

of dynamic and static stretching as part of a warm-up

protocol, and how they affect an athlete’s performance.

Research done previously on this topic will be analyzed

and discussed to support this subject matter.

Traditionally, static stretching (holding a stretch

position for a period of time with little or no movement)

has been the common method of stretching used before an

athletic event.2-20 However, dynamic stretching

(controlled movement through the active range of motion),

is becoming more and more popular in the field of

athletic performance.2,3,5,7,9,12-16,19-24,25,30 This review of

literature is divided into four sections: 1) Stretching

and Flexibility, 2) Stretching and Power, 3) Stretching

and Performance, and 4) Stretching and Injury Risk. A

summary of the literature review is also included.

29

Stretching and Flexibility

The act of stretching has been a component of the

traditional method of warm-up by athletes prior to

athletic events at all levels of competition. The recent

literature concerning whether stretching is more harmful

than beneficial is a concern among athletic trainers

everywhere. However, before examining the literature on

stretching in relation to performance as well as injury

risk, it is necessary to understand the workings of the

muscle-tendon unit.

Mechanisms of Stretching

Flexibility refers to the musculotendinous unit’s

(MTU) ability to elongate with the application of a

stretching force, determining the range of motion

available at a joint.1,2 Therefore, the act of stretching

can be defined as movement applied by an external or

internal force in order to increase muscle flexibility

and/or joint range of motion.3 It is important to

understand what is occurring physiologically when a

muscle responds to a stretching force. To grasp this

concept it is necessary to begin with the basic anatomy

of the MTU.

30

The MTU is made up of muscle cells, nerves,

connective tissue, and blood vessels. Each muscle cell

is called a muscle fiber, which are cylindrical and

arranged parallel to one another. They run the entire

length of an individual muscle and are held in place by

connective tissue.4-6 Proprioceptors, known as muscle

spindles, are located within the body of the muscle and

are parallel to the other muscle fibers. These muscle

spindles are surrounded by special sensory nerves that

produce impulses when the length and rate of the muscle

spindle is altered. When the muscle spindles are

stimulated, a reflexive response is created which causes

the muscle to contract, also causing an inhibition of the

antagonist muscle.1,4-6 The muscle contracts when it is

put on a stretch, to prevent the overstretching of the

muscle. This excitation of the muscle spindles causing a

reflex contraction of the stretched muscle is known as

the stretch reflex.1,4-6

There are also proprioceptors called golgi tendon

organs (GTO) which sense tension in the muscle. GTO’s

are sensory nerve endings that are wrapped around the

fibers of tendons. When GTO’s are stimulated by sensing

increased muscle tension, there is a reflex inhibition in

the muscle where tension is being produced. This reflex

31

provides a negative feedback mechanism, preventing too

much tension in the muscle, thus protecting it from

injury.1-6

Force deformation is the amount of force that is

applied when putting a muscle on a stretch, to change the

length of the tissue. If the force is applied too

quickly and is too much for the tissue to tolerate, the

muscle spindles and GTO’s do not have enough time to

respond and injury can result.1 When tissues are held

at a constant force, the deformation continues, causing a

change in the tissue length. This is known as creep.

The effect of creep can be affected by how much time the

load is applied. For example, a load that is applied for

a longer time such as a static stretch, causes a greater

increase in tissue length than a load that is applied and

released more quickly.1,3

Stretching Techniques

There are a number of different stretching

techniques used in athletics, depending on various

factors, such as the type of sport, the athlete or

coach’s preference, or even the training program a team

may be using. The four most common techniques that are

widely used in the sport setting are static,

32

Proprioceptive neuromuscular facilitation (PNF),

ballistic, and dynamic.1-3,8

Static stretching is the most common and traditional

stretching technique used in the athletic setting.

Static stretching can be defined as holding a stretch for

a period of time with little or no movement.8 This type

of stretching has been found to increase musculoskeletal

flexibility by affecting both the mechanical and

neurological properties of the muscle tendon unit.3

However, there is evidence that puts the effectiveness of

static stretching into question, suggesting that it may

not be the most beneficial method and may even decrease

performance and increase injury rates.1-3,8,10,12,15-18,21-27,31,32

Many sports require the use of bursts of speed from a

slowly moving or stationary position, such as a track or

swimming start. Using static stretching as part of a

warm-up for these types of sports might not prepare the

muscles as well as stretching that incorporates

functional movements as in dynamic stretching.8,32

Proprioceptive neuromuscular facilitation was

developed in the 1950’s and includes several techniques

to increase flexibility such as slow-reversal-hold,

contract-relax, and hold-relax. These techniques use a

combination of both contraction and relaxation of both

33

agonist and antagonist muscles.1,8 PNF has been thought

to cause a greater improvement in range of motion as

compared to static stretching.8 In a study that compared

dynamic, static, and PNF stretching by Lucas and Koslow,9

it was found that all three methods of stretching

produced significant increases in flexibility from pre-

test to posT-test for agility.

Ballistic stretching is a rhythmic bouncing type of

movement that repeatedly produces high levels of tension

very rapidly.10 This type of stretch is not quite as

common due to the fact that it is thought to be more

harmful than the other techniques. During this type of

stretch, the muscle is stretched very quickly and then

released quickly producing high levels of tension very

rapidly within the muscle tendon unit. This does not

allow enough time to release the tension or increase the

length, creating a high level of tension development,

which may cause harm to the athlete.3,8,10

Although the uncontrolled bouncing type of ballistic

stretching is not suggested in athletics, controlled

movement through stretching, known as dynamic stretching,

is becoming very popular and can be very beneficial as a

warm-up. Shellock and Prentice11 reported in their review

of stretching that dynamic stretching is essential in

34

athletic performance because it is important for joints

to be capable of moving through the available range of

motion while the muscle is put on a stretch.3,11 This

allows the athlete to go through sport specific movements

while putting their muscles on a stretch, much like they

will be doing in practice or competition.10

Stretching and Power

Pre-exercise stretching has not only been linked to

injury risk and decreases in sport performance, but may

also decrease a muscle’s ability to produce force,

reducing an athlete’s strength. There are two primary

theories proposed to explain this stretching-induced

strength deficit. The first is linked to the mechanical

factors of the muscle such as changes in length tension

relationships, and the second theory relates to the

neuromuscular factors, such as decreased motor unit

activation.12,13 Researchers have also proposed that the

mechanism for this stretching induced strength deficit

may be related to a decrease in muscle stiffness that

could in turn, alter the length tension relationship of

the muscle fibers.12,13

35

There have been many recent studies looking at the

acute effect of stretching on muscle strength and power.

The majority of these studies have found that of all the

stretching techniques, static stretching had a negative

affect on maximal performance of peak torque as a measure

of strength.13-17 In a study by Marek et al12 it was

hypothesized that stretching may have altered the length-

tension relationship, as well as the plastic deformation

of the tissues, resulting in the force production being

limited. Static and PNF stretching techniques were

compared examining both peak torque, mean power, and

active and passive range of motion. Peak torque and mean

power were both reduced following both the static and PNF

stretching.12

A study by Papadopoulos et al14 was conducted to

examine the effect of static and dynamic stretching

exercises on the maximal isokinetic torque of the knee

extensor and flexor muscles. The results showed a

significant difference on maximal isokinetic torque of

these muscles following the two different stretching

techniques. The torque was significantly reduced with

the static stretching exercises, while no effect was seen

when preceded with the dynamic stretching exercises. A

similar study by Fowels et al15 found that when looking at

36

the maximal isometric torque of the plantar flexor

muscles, torque was reduced by 30% after a static

stretching regimen immediately afterward. Sixty minutes

after the stretching took place, isometric torque was

still reduced by 9%.15 This length of time shows that pre-

exercise stretching may negatively affect athletes’

ability to produce peak torque in their sport as the

reduction lasts for at least 60 minutes. Another study

found there to be a reduction in isometric torque after a

few minutes of static stretching, however, torque was

back to normal 10 to 15 minutes later.16 In a study by

Nelson et al17 it was found that when prone knee flexion

exercises were performed at 60% as well as 40% of body

weight, static stretching significantly reduced strength.

The results of this study suggest that static stretching

exercises should be avoided prior to performances

requiring maximal strength production.17

Stretching and Performance

In addition to static stretching as part of a warm-

up resulting in a decrease in strength production, this

stretching technique has been linked to a decrease in

performance level as well.18-22 This is a major problem

37

for athletes, as their main goal of competing is to

achieve the best performance possible to succeed in their

sport. The most common reasoning behind this decrease in

performance following static stretching is that it causes

the musculotendinous unit to become more compliant, which

decreases stiffness, thus, reducing the force

development.18 The reduction in the stiffness in the

musculotendinous unit leads to neural inhibition,

reducing the neural drive to the muscle. Finally, this

leads to a reduction in force and power output. Each

muscle fiber in the body has a range in which it has the

best available force production. When that length is

exceeded, as with sustained static stretching, the

potential force production drops considerably.1 The

recent research on static stretching and its negative

effect on sport performance and injury risk has

interested sports medicine professionals in learning more

about the most effective warm-up methods to positively

benefit performance.18,20-22 One answer may be dynamic

stretching. Although there has not been an abundance of

studies performed on this topic thus far, the majority of

the research examining the different warm-up stretch

protocols is consistent, in favor of dynamic

stretching.18,20-22

38

A study by Fletcher 18 was performed to determine the

effect of different static and dynamic stretch protocols

on a 20 meter sprint performance in trained rugby

players. It was found that the groups participating in

the static stretching warm-up had a significant increase

in their sprint time from their pretest time. This

decrease in performance was theorized to have been due to

an increase in the musculotendinous unit compliance,

which in turn led to a reduction in the ability of the

MTU to store energy. The dynamic stretching groups

decreased their sprint times significantly, which could

be linked to the movement patterns being so similar to

the actual movements and coordination required for

sprinting. These results showed that dynamic stretching

as a pre-participation warm-up increased performance,

whereas static stretching significantly decreased

performance.18 Similarly, in a study by Siatras et al19

examining gymasts’ vaulting speeds, it was found that

vault speeds were significantly decreased following

static stretching exercises. There was no effect on the

performance of the dynamic stretching protocol, which

could be attributed to neurological mechanisms.19

In contrast, Little and Williams20 found static

stretching not to be detrimental to the velocity

39

performance in professional soccer players. However,

dynamic stretching was found to be the most effective as

a warm-up for performance producing significantly faster

10m sprint, 20m sprint, and agility times than either a

non-stretch protocol or a static stretching protocol.20

Dynamic stretching was also found to be the most

effective stretching technique in a study by McMillian et

al,21 revealing better performance scores in the T-shuttle

run, medicine ball throw, and the 5-step jump as compared

to static stretching and no stretching.21

Two very similar studies, conducted by Faigenbaum et

al(22,23) looked at the acute effects of different warm-up

protocols on the performance of young children and

adolescents. Results were consistent in both studies,

showing that pre-event dynamic stretching alone or in

conjunction with static stretching is more beneficial

than static stretching alone in relation to performance

in both teenage athletes as well as younger children.22,23

A study conducted by Knudson et al24 solely examining the

effect of static stretching on the speed and accuracy of

a tennis serve performance found no significant

difference when incorporating static stretching as a part

of the warm-up as compared to no stretching at all. This

study suggests that as static stretching may negatively

40

affect many types of performances, it does not

necessarily affect the performance of a tennis serve.24

Another study by Nelson et al25, also investigated the

effects of static stretching on a 20 m sprint

performance, without the comparison of a dynamic

stretching group. Contradictory to Knudson’s study,

Nelson found there to be a significant increase in the 20

meter sprint times of Division I NCAA track athletes who

engaged in a pre-event static stretching protocol as

compared to no stretching at all.25 A number of studies

have looked at jump performance as a test after different

stretching protocols have been performed. A study by

Unick et al26 found no significant difference in vertical

jump scores when comparing static and ballistic

stretching. In a study comparing static stretching,

proprioceptive neuromuscular facilitation and a control

group by Church et al,27 results showed a significant

decrease in vertical jump performance for the PNF

stretching group as compared to the static stretching and

control groups.27

Although there is still some contradictory evidence

regarding static and dynamic stretching, the majority of

recent literature examining the effects of these

stretching techniques is in support of dynamic

41

stretching.18-23 The benefits obtained from this technique

are thought to stem from facilitated motor control from

rehearsing the specific movements before the actual

event, increased muscle blood flow and elevated core

temperature. This elevated temperature increases the

sensitivity of nerve receptors as well as increases the

speed of nerve impulses, which in turn causes muscle

contractions to be faster and more forceful.21-23

Stretching and Injury Risk

Along with a decrease in performance and muscle

strength, static stretching also has been linked to an

increased risk of injury. The literature concerning

stretching and injury risk is minimal and needs to be

further researched. Injury may be related to either too

much or too little flexibility, and in some instances

increasing flexibility may increase the rate of

injury.2,29-31 There are, however, some sports that

require this increase in flexibility such as gymnastics

or wrestling, however it has been found that increased

flexibility before competition may compromise muscle

performance for up to one hour.2

42

Evidence exists from randomized trials noting that

pre-exercise stretching using a specific stretching

protocol does not result in a reduction of injury risk.

Shrier28 noted five theoretic arguments against pre-

exercise stretching for injury prevention. The first

argument deals with the compliance, or the length change

in a muscle when a force is applied. Increased muscle

compliance is related to a decreased ability to absorb

energy at rest. However, a contracting muscle can absorb

more force, but is less compliant. Therefore, stretching

does increase the compliance, however this is not related

to the tissue’s resistance to injury.28,29 Shrier’s second

argument is related to the sarcomere length. When the

sarcomeres are stretched to the point at which the actin

and myosin do not overlap, this causes fiber damage. The

third is that muscle compliance may be irrelevant to

injury. The fourth argument is that the muscle tissue

compliance during activity and at rest is unrelated. If

stretching increases compliance at rest, this indicates

that stretching does not support the fact that when the

muscle is active there is a decrease in injury risk.

Lastly, Shrier28 argues that increased range of motion may

be a result of an increase in stretch tolerance.

Therefore, stretching does not increase tissue

43

compliance, it merely increases the stretch tolerance

during the stretching procedure.

A study by Johansson et al30 investigated the effects

of pre-exercise stretching on delayed onset muscle

soreness (DOMS). No significant difference was found

between the stretched and the non-stretched limbs. A

very similar study by Lund et al31 also looked at passive

stretching on DOMS as well as on dynamic muscle strength,

plasma creatine kinase concentration, and the ratio of

phosphocreatine to inorganic phosphate following

eccentric exercise. It was concluded that passive

stretching did not have any significant influence on

increased plasma creatine phosphate concentration, muscle

pain, or muscle strength. These two studies suggest that

passive static stretching done either pre or post

exercise, has no effect on muscle soreness, or decrease

in force production.30,31

Summary

Stretching is performed in athletic events everyday,

and it is very important for athletic trainers to

understand the physiological workings of the

musculotendinous unit to have a better understanding of

44

what is actually going on when a muscle is put on a

stretch. This background information as well as reading

the recent literature can be very beneficial in choosing

the correct stretching techniques for your athletes.

Despite the inconsistent evidence pertaining to these

stretching techniques, all of these types of stretching

are used in the athletic setting.

Overall, the results obtained from the studies

related to strength and power, indicate that static

stretching negatively effects strength production.13-17

This information should be used by strength and

conditioning professionals, athletic trainers, coaches,

and athletes to help achieve the most optimal level of

strength performance. Future research should be carried

out to support these findings and to find the underlying

mechanisms that cause this decrease in maximal force

production for individuals participating in athletics.

The compiled findings from the recent literature

related to performance are, for the most part, in

accordance with each other. The previously examined

studies have shown that static stretching may be

detrimental to an athlete’s performance, favoring dynamic

stretching, which is shown to be much more beneficial.18-

23,25 These results have led to a great deal of interest

45

from coaches, athletes, and athletic trainers, who are

beginning to move away from the traditional method of

static stretching and incorporating dynamic stretching

into their warm-up routines.18,20-22

The results of the literature dealing with

stretching and injury risk are conflicting, with some

studies suggesting that stretching has no effect on

injury or muscle soreness and others that do not support

pre or post exercise stretching at all, due to its

supposed detrimental effects.2,29-31 This is an area of

concern, and there is a need for further studies to be

conducted to build on these previous findings.

46

APPENDIX B

The Problem

47

The Problem

Statement of the Problem

It has been previously accepted in the athletic

population that increasing flexibility promotes increased

performance and decreases the risk of injury.3,10,17,25-27,32

Stretching is incorporated in many aspects of sports,

especially in warm-up and cool down exercises, and are

performed everyday.1-3,8,12,15,16,18,21-26,31 However, recent

research suggests that performing static stretching

before performance may contribute to increased injury and

a decrease in performance, which can be detrimental to

the health and abilities of our athletes.1-3,8,10,12,15-18,21-

27,31,32 Dynamic stretching is becoming more and more

popular and could be a helpful alternative to the

traditional method of static stretching.18-23 The purpose

of this study is to compare the effect of static and

dynamic stretch protocols on the performance of the T-

test for agility in Division III Collegiate football

players.

48

Definition of Terms

The following definitions of terms will be defined

for this study:

Operational Definitions:

1) Dynamic stretching protocol – Stretching protocol

including high knees, drop lunges, flick backs,

lateral shuffles, and heel to toe walks. The

subjects will perform 20 repetitions on each leg.

2) Static stretching protocol – stretching protocol

including a gluteal stretch, hip flexor stretch,

hamstring stretch, quadriceps stretch, adductor

stretch, abductor stretch, and a gastroc/soleus

stretch, with the stretches being held for 20

seconds each bilaterally.

3) T-test for agility - test to measure agility

requiring the athlete to sprint forward, laterally,

and backward as quickly as possible. The subject

will sprint forward first, then shuffle laterally

to one side, then the other (without crossing over

their feet), and then backward. The subjects will

be put through this test to see how their times

differ following the different stretching

protocols.

49

Basic Referenced Definitions:

1) Agility - the ability to control the direction of a

body or its parts during rapid movement.1

2) Flexibility – The musculotendinous’s ability to

elongate with the application of a stretching force,

determining the range of motion available at a

joint.1,2,4-6

3) Stretching - movement applied by an external or

internal force in order to increase muscle

flexibility and/or joint range of motion.3

4) Dynamic stretching - controlled movement through the

active range on motion.3,11

5) Static stretching – holding a stretch for a period

of time with little or no movement.8

6) Proprioceptive Neuromuscular Facilitation (PNF)-

stretching technique that includes the combination

of alternating contraction and relaxation of both

agonist and antagonist muscles.1,3

7) Ballistic Stretching – rhythmic bouncing movement

that repeatedly produces high levels of tension

rapidly.10

8) Force deformation – musculotendinous unit’s ability

to elongate with the application of a stretching

force, determining the range of motion available1,2

50

9) Golgi tendon organ (GTO) – sensory nerve endings

located in the tendons that sense changes in muscle

tension. Through connections with motor neurons in

the spinal cord, it inhibits the contracting muscle

protecting it from injury.1,4-6,8

10) Muscle spindles – proprioceptors found in skeletal

muscle that are sensitive to stretch, and signals

muscle length and rate of change in the muscle’s

length.1,4-6

11) Stretch reflex – response to a muscle being

stretched whereas the excitation of the muscle

spindles causes a reflex contraction of the

muscle.1,4,5,6,8

Basic Assumptions

The following were basic assumptions of this study:

1) The subjects did not perform any other stretching

then the stretching asked of them in this study.

2) The subjects performed the T-test for agility to

the best of their ability.

3) The equipment was calibrated and utilized properly

during the course of this study.

4) The T-test for agility is a valid and reliable

performance test.

51

Limitations of the Study

The following are limitations for this study:

1) The results can only be generalized to Division III

football players.

2) The 5 minute jog warm-up was done at the subject’s

own pace, making it difficult to measure and ensure

consistency.

3) The subjects are volunteers.

4) The same person will serve as the researcher, the

data collector and the Athletic Trainer.

Significance of the Study

Traditionally, stretching and flexibility training

have been very common in the world of athletics, making

up a large part of training programs as well as pre-event

warm up activities for athletes. 1-3,8,12,15,16,18,21-26,31 It

has long been theorized that increasing flexibility is

one of the most important elements of physical fitness,

contributing to enhanced athletic performance and

reducing the incidence of injury.3,10,17,25-27,32 However,

recent research has found that the acute effects of

stretching may have negative results on both performance

and risk of injury. 1-3,8,10,12,15-18,21-27,31 Studies have shown

that intense static stretching may predispose athletes to

52

musculoskeletal injury rather than preventing injuries

from occurring. The effects of increased flexibility

after stretching are attributed to a decrease in the

muscle-tendon unit as well as decreasing joint stability,

making athletes more prone to injury.18,27 In addition to

this, it has also been reported that stretching before

participation may cause a decrease in muscle strength and

power output, jumping performance, and sprint

performance.3,12,13,17,18,19-23,25-27 If this new research is

valid, Athletic Trainers need to be aware of this

information to implement the most safe and beneficial

warm-up techniques for our athletes. These recent

developments regarding this issue have caused many

coaches, athletes, and Athletic Trainers to move away

from static stretching as a warm-up, and instead

implement dynamic stretching18,20-22

Dynamic stretching can be defined as a controlled

movement through the active range of motion for each

joint.18 Although dynamic stretching is becoming more

popular, the literature examining its effect as a warm-up

seems to be lacking. Our primary concern as Athletic

Trainers is providing the best possible care for our

athletes. If evidence shows that one stretching

technique is not as effective as another, especially if

53

it causes harm to a patient, it is vital that we change

our protocol to be the most beneficial to the patient.

Thus, if dynamic stretching is more effective as a warm-

up than static stretching, additional research should be

performed to apply validity and reliability to the study

to begin implementing this change.

54

APPENDIX C

Additional Methods

55

APPENDIX C1

Informed Consent Form

56

Informed Consent Form

1. "Jaclyn C. Oakley, who is the researcher, hasrequested my participation in a research study at thisinstitution. The title of the research is The Effect ofStatic and Dynamic Stretching Protocols on Performance inDivision III Football Players.''

2. "I have been informed that the purpose of the researchis to compare the effect of static stretching, dynamicstretching, or no stretching on the performance of theT-test for agility in Division III Collegiate footballplayers." I understand that 21 members of the footballteam will be tested for research purposes.

3. "My participation will involve filling out an informedconsent form before beginning the study. For theexperimental portion of the study, I will be asked tojog for 5 minutes as a warm-up. I will then be askedto do either an active dynamic stretch protocol, anactive static stretch protocol, or no stretching,followed by two trials of the T-test for agility. Iwill participate in this study on six separate days sothat I complete each stretching protocol twice.

4. "I understand there are foreseeable risks ordiscomforts to me if I agree to participate in the study.The possible risks and/or discomforts include possiblesoreness due to activity. To minimize these risks anddiscomforts the researcher has included a proper warm-upconsisting of a 5 minute jog before participating in theperformance testing.”

57

5. "I understand that in case of injury I can expect toreceive treatment or care in Washington and Jefferson’sHenry Gymnasium, which will provided by the studentresearcher, Jaclyn Oakley, or another CertifiedAthletic Trainer, either of whom can administeremergency and rehabilitative care. Additional servicesneeded for prolonged care past 3 days will be referredto the team physician. I understand that I will beresponsible for payment of any services provided by theteam physician or other medical professional above orbeyond those provided by the student researcher orother Athletic Trainer.”

I

6." There are no feasible alternative proceduresavailable for this study."

7. "I understand that the possible benefits of myparticipation in the research are to provide more currentresearch, adding to the existing research, which willcontribute to which type of stretching protocol will bethe most effective in terms of improving performance aswell as decreasing injury in athletics.”

8. "I understand that the results of the research studymay be published but that my name or identity will not berevealed. In order to maintain confidentiality of myrecords, Jaclyn C. Oakley will maintain all documents ina secure location in which only she, the studentresearcher and research advisor can access."Confidentiality will be maintained by the subjects beingassigned a number and will be referred to only by thosenumbers during the testing.”

9. "I have been informed that I will not be compensatedfor my participation."

10. “I have been informed that any questions I haveconcerning the research study or my participation in it,before or after my consent, will be answered by Jaclyn C.Oakley, oak3434@cup.edu, 947 Cross Street Apt.1,California, PA 15419, (570)449-2498, and Dr. Ben Reuter,reuter@cup.edu, Dept of Health Science and Sport Studies,Box 14, California University of Pennsylvania, 15419,(724) 938-4356.”11. "I have read the above information. The nature,

demands, risks, and benefits of the project have been

58

explained to me. I knowingly assume the risksinvolved, and understand that I may withdraw myconsent and discontinue participation at any timewithout penalty or loss of benefit to myself. Insigning this consent form, I am not waiving any legalclaims, rights, or remedies. A copy of this consentform will be given to me upon request."

Subject’s name (print) ______________________________

Subject'ssignature________________________________________________Date________________

12. "I certify that I have explained to the aboveindividual the nature and purpose, the potentialbenefits, and possible risks associated withparticipation in this research study, have answeredany questions that have been raised, and havewitnessed the above signature."

13. "I have provided the subject/participant a copy ofthis signed consent document if requested."

Investigator’ssignature________________________________________________Date________________

Approved by the California University of Pennsylvania IRB

59

APPENDIX C2

Functional Testing and Equipment

60

T-test for agility

http://www.scrum.com

61

Speed Trap II Timer™

http://www.powersystems.com/nav/closeup.aspx?c=19&g=1354#

62

APPENDIX C3

Stretching Protocols

63

Active Static Warm-up Stretching Protocol

Stretch Muscles Sets Repetitions

Glutealstretch

Gluts 120 sec

bilaterally

Hip Flexorstretch

Hip Flexors 120 sec

bilaterally

Hamstringstretch

Hamstrings 120 sec

bilaterally

Quadricepsstretch

Quadriceps 120 sec

bilaterally

Abductorstretch

Abductors 120 sec

bilaterally

AdductorStretch

Adductors 120 sec

bilaterally

Gastroc/soleusstretch

Gastroc/Soleus 120 sec

bilaterally

64

Active Static Warm-up Stretching Protocol

a. b.

c. d.

e. f. g.

a.)hamstring stretch b.) quadriceps stretch c.) adductorstretch d.) gluteal stretch e.) hip flexor stretch f.)gastroc/soleus stretch g.)abductor stretch

65

Active Dynamic Warm-up Stretching Protocol

Stretchingexercises

Muscles Sets Repetitions

High Knees Gluts/Hamstrings 120

Bilaterally

Drop Lunges Gluts/Hip Flexors

120

Bilaterally

Flick Backs Quadriceps/HipFlexors

120

Bilaterally

LateralShuffles

Abductors/Adductors 120

Bilaterally

Heel to ToeWalk

Gastroc/soleus 120

bilaterally

66

Active Dynamic Warm-up Stretching Protocol

a. b.

c. d.

e.

a.) high knees b.) flick backs c.) lateral shufflesd.) drop lunge walk e.) heel to toe walk

67

APPENDIX C4

Institutional Review Board

68

69

Please attach a typed, detailed summary of your project AND complete items 2through 6.1. Provide an overview of your project-proposal describing what you plan to do and how

you will go about doing it. Include any hypothesis(ses)or research questions that mightbe involved and explain how the information you gather will be analyzed. For a completelist of what should be included in your summary, please refer to Appendix B of the IRBPolicies and Procedures Manual

* The purpose of this study is to compare the effects of dynamic stretching, static stretching,and no stretching on performance. The main hypothesis of this study is that there will not bea difference between static stretching, dynamic stretching, and no stretching on the time tocomplete the T-test for agility. All data will be analyzed using SPSS version 14.0 forWindows, with a .05 alpha level. Scores for each group on the dependent variable, the T-testfor agility, will be used. Hypothesis one will be analyzed using a repeated measures ANOVA.

2. Section 46.11 of the Federal Regulations state that research proposals involving humansubjects must satisfy certain requirements before the IRB can grant approval. Youshould describe in detail how the following requirements will be satisfied. Be sure toaddress each area separately.

a. How will you insure that any risks to subjects are minimized? If there arepotential risks, describe what will be done to minimize these risks. If there arerisks, describe why the risks to participants are reasonable in relation to theanticipated benefits

* The possible risks and/or discomforts include possible soreness due to activity. Tominimize these risks and discomforts the researcher has included a proper warm-upconsisting of a 5 minute jog before participating in the performance testing. In case ofinjury the subject can expect to receive treatment or care in the Henry Gymnasium atWashington and Jefferson College, which will provided by the student researcher, JaclynOakley, or another Certified Athletic Trainer, either of whom can administer emergencyand rehabilitative care. Additional services needed for prolonged care past 3 days willbe referred to the team physician. The subjects understands that they will be responsiblefor payment of any services provided by the team physician or other medical professionalabove or beyond those provided by the student researcher or other Athletic Trainer.”

b. How will you insure that the selection of subjects is equitable? Take into accountyour purpose(s). Be sure you address research problems involving vulnerablepopulations such as children, prisoners, pregnant women, mentally disabledpersons, and economically or educationally disadvantaged persons. If this is anin-class project describe how you will minimize the possibility that students willfeel coerced.

* The purpose of the research is to compare the effect of static stretching, dynamicstretching, or no stretching on the performance of the T-test for agility in Division IIICollegiate football players. In this study it is pertinent to use 21 members of thefootball team to determine which stretching technique will most benefit the athletes.Participation will be voluntary.

c. How will you obtain informed consent from each participant or the subject’slegally authorized representative and ensure that all consent forms are

70

appropriately documented? Be sure to attach a copy of your consent form to theproject summary.

*The subject’s participation will involve filling out an informed consent form beforebeginning the study.

d. Show that the research plan makes provisions to monitor the data collected toinsure the safety of all subjects. This includes the privacy of subjects’ responsesand provisions for maintaining the security and confidentiality of the data.

*The results of the research study may be published but the names or identity of thesubjects will not be revealed. In order to maintain confidentiality of the subjects’records, Jaclyn C. Oakley will maintain all documents in a secure location in whichonly the student researcher and research advisor can access. Confidentiality will bemaintained by the subjects being assigned a number and will be referred to only bythose numbers during the testing.

3. Check the appropriate box(es) that describe the subjects you plan to use.

Adult volunteers

CAL University Students

Other Students

Prisoners

Pregnant Women

Physically Handicapped People

Mentally Disabled People

Economically Disadvantaged People

Educationally Disadvantaged People

Fetuses or fetal material

Children Under 18

Neonates

4. Is remuneration involved in your project? Yes or No. If yes, Explain here.

5. Is this project part of a grant? Yes or No If yes, provide the followinginformation:

Title of the Grant Proposal

Name of the Funding Agency

Dates of the Project Period

6. Does your project involve the debriefing of those who participated? Yes or No

If Yes, explain the debriefing process here.

7. If your project involves a questionnaire interview, ensure that it meets the requirementsof Appendix __ in the Policies and Procedures Manual.

71

72

APPENDIX C5

Athletic Director Consent Form

73

74

APPENDIX C6

Data Collection Sheet

75

Agility time on the T-test for agility

DynamicStretching

StaticStretching

NoStretching(control)

SubjectNumber

T1 T2Best

T1 T2Best

T1 T2Best

76

Agility Time on the T-test for agility

DynamicStretching

StaticStretching

NoStretching(control)

SubjectNumber

T1 T2Best

T1 T2Best

T1 T2Best

77

REFERENCES

1. Houglum PA. Therapeutic Exercise for AthleticInjuries. Champlain IL: Human Kinetics; 2001.

2. Thacker SB, Gilchrist J, Stroup DF, Kimsey DC. TheImpact if Stretching on Sports Injury Risk: ASystematic Review of the Literature. Med and Sciencein Sports Exercise. 2004;36:371-378.

3. Weerapong P, Hume PA, Kolt GS. Stretching:Mechanisms and Benefits for Sport Performance andInjury Prevention. Physical Therapy Reviews.2004;9:189-206.

4. Guyton AC, Hall JE. Textbook of Medical Physiology.Philadelphia PA: W.B. Saunders Company;1996.

5. Cerney FJ, Burton HW. Exercise Physiology for HealthCare Professionals. Champlain IL: HumanKinetics;2001.

6. Premkumar K. Anatomy and Physiology. PhiladelphiaPA: Lippincot and Williams and Wilkins;2004.

7. Prentice WE. Arnheim’s Principles of AthleticTraining: A Competency-Based Approach. New York NY:McGraw-Hill Co. Inc.; 2003.

8. Mann D, Whedon C. Functional Stretching:Implementinga Dynamic Stretching Program. Athletic TherapyToday. 2001;6:10-13.

9. Lucas RC, Koslow R. Comparitive Study of Static,Dynamic, and Proprioceptive NeuromuscularFacilitation Stretching Techniques on Flexibility.Percept. Mot. Skills.1984;58:615-618.

10. Haff GG. Roundtable Discussion: FlexibilityTraining. Strength Cond. J. 2006;28:64-85.

11. Shellock FG, Prentice WE. Warming-up and Stretchingfor Improved Physical Performance and Prevention ofSports-Related Injuries. Sports Med.1985;2:267-278.

78

12. Marek SM, Cramer JT, Fincher LA, et al. AcuteEffects of Static and Proprioceptive NeuromuscularFacilitation Stretching on Muscle Strength and PowerOutput. J. Athl. Train. 2005;4094-103.

13. Cramer JT, Housh TJ, Johnson GO, Miller JM. CoburnJW, Beck TW. Acute Effects of Static Stretching onPeak Torque in Women. J. Strength Cond. Res.2004;18:236-241.

14. Papadopoulos G, Siatras T, Kellis S. The Effect ofStatic and Dynamic Stretching Exercises on theMaximal Isokinetic Strength of the Knee Extensorsand Flexors. Isokinetics and Exercise Science.2005;13:285-291.

15. Fowles JR, Sale DG. Time Course of Strength Deficitafter Maximal Passive Stretch Humans. Medicine andScience in Sports and Exercise. 1997;29:26.

16. Kokkonen J, Nelson AG, Cornwell A. Acute MuscleStretching Inhibits Maximal Strength Performance.Research Quarterly from Exercise and Sport.1998;69:411-415.

17. Nelson AG, Kokkonen J, Arnall DA. Acute MuscleStretching Inhibits Muscle Strength EndurancePerformance. J. Strength Cond. Res. 2005;19:338-343.

18. Fletcher IM. The Effect of Different Warm-upProtocols on 20 Meter Sprint Performance in TrainedRugby Players. J. Strength Cond. Res. 2004;18:885-888.

19. Siatras T, Papadopoulos G, Mameletzi D, Kellis S.Static and Dynamic Acute Stretching Effect onGymnasts’ Speed in Vaulting. Pediatr Exerc Sci.2003;15:383-391.

20. Little T, Williams A. Effects of DifferentialStretching Protocols During Warm-ups on High-SpeedMotor Capacities in Professional Soccer Players. J.Sports Sci. 2004;22:589-590.

21. McMillian DJ, Moore JH, Hatler BS, Talor DC. Dynamicvs. Static-Stretching Warm Up: The Effect on Power

79

and Agility Performance. J. Strength Cond. Res.2006;20:492-499.

22. Faigenbaum AD, Bellucci M, Bernieri A, Bakker B,Hoorens K. Acute Effects of Different Warm-upProtocols on Fitness Performance in Children. J.Strength Cond. Res. 2005;19:376-381.

23. Faigenbaum AD, Kang J, McFarland J, Bloom JM. AcuteEffects of Different Warm-Up Protocols on AnaerobicPerformance in Teenage Athletes. Pediatr Exerc Sci.2006;17:64-75.

24. Knudson DV, Noffal GJ, Bahamonde RE, Bauer JA.Blackwell JR. Stretching Has No Effect on TennisServe Performance. J. Strength Cond. Res.2004;18:654-656.

25. Nelson AG, Driscoll NM, Landin DK, Young MA,Schexayder IC. Acute Effects of Passive MuscleStretching on Sprint Performance. J. Sports Sci.2005;23:449-454.

26. Unick J, Kieffer SH, Cheesman W, Feeney A. The AcuteEffects of Static and Ballistic Stretching onVertical Jump Performance in Trained Women. J.Strength Cond. Res. 2005;19:206-212.

27. Church BJ, Wiggins MS, Moode MF, Crist R. Effect ofWarm-Up and Flexibility Treatments on Vertical JumpPerformance. J. Strength Cond. Res. 2001;15:332-336.

28. Shrier I. Stretching Before Exercise Does Not Reducethe Risk of Local Muscle Injury: A Critical Reviewof the Clinical and Basic Science Literature. ClinJ. Sport Med. 1999;9:221-227.

29. Anderson JC. Stretching Before and After Exercise:Effect on Muscle Soreness and Injury Risk. J. Athl.Train. 2005;40:218-220.

30. Johansson PH, Lindstrom L, Sundelin G, Lindstrom B.The Effects of Preexercise Stretching on MuscularSoreness, Tenderness and Force Loss Following HeavyEccentric Exercise. Scand. J. Med. Sci. Sports.1999;9:219-225.

80

31. Lund H, Vestergaard-Poulsen P, Kanstrup IL, SejrsenP. The Effect of Passive Stretching on Delayed OnsetMuscle Soreness, and other Detrimental EffectsFollowing Eccentric Exercise. Scand. J. Med. Sci.Sports. 1998;8:216-221.

32. Witvrouw E, Mahieu N, Danneels L, McNair P.Stretching and Injury Prevention: An ObscureRelationship. Sports Med. 2004;34:443-449.

33. Brower Timings Systems. http://www.browertiming.com.Accessed October 22, 2006.

81

ABSTRACT

TITLE: THE EFFECT OF DYNAMIC AND STATICSTRETCHING ON PERFORMANCE

Researcher: Jaclyn C. Oakley

Advisor: Dr. Ben Reuter

Date: 4/20/07

Research Type: Master’s Thesis

Purpose: The purpose of this study was toexamine the differences between threestretching protocols on theperformance of the T-test for agilityin Division III collegiate footballplayers.

Problem: Recent research has found that theacute effects of stretching may havenegative results on both performance.

Method: Eighteen male subjects from aDivision III football team,volunteered for this study. Eachsubject was tested on six separatedays. All subjects performed a 5minute jog warm-up first. Subjectsthen rested for two minutes.Subjects then performed theirrandomly assigned protocol. They hadanother rest period of two minutes.They performed two trials of the T-test for agility with one minute restin between trials. The best time wasrecorded.

Findings: A significant effect was found(F(2,34)= 5.518, p < .001.)

Conclusion: This study revealed that the type ofstretching protocol has a significanteffect on agility performance inDivision III collegiate footballplayers.