Download correlation between muscular strength and flexibility

CORRELATION BETWEEN MUSCULAR STRENGTH AND FLEXIBILITY
BILLY WILSON
SPRING 2008
HHP456
ABSTRACT
The muscular strength and flexibility of 59 male volunteers that were attending a major
metropolitan university were collected in the following research study. The subjects were
between the ages of 18-38. The one repetition maximum bench press was used to determine the
upper body strength of the subjects. Flexibility measurements of shoulder flexion were taken
using a goniometer. These measurements were compared using the Spearman r method of data
analysis. The results of the study showed that there was no correlation between the muscular
strength and flexibility of college age males.
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TABLE OF CONTENTS
Chapter One .............................................................................................................5
Introduction ................................................................................................................6
Purpose of the Study ..................................................................................................6
Statement of the Problem ...........................................................................................6
Hypothesis of the Study .............................................................................................6
Need for the Study .....................................................................................................6
Delimitations of the Study .........................................................................................7
Limitations of the Study.............................................................................................8
Basic Assumptions .....................................................................................................8
Definitions and Interpretations ..................................................................................8
Reference ...................................................................................................................10
Chapter Two .............................................................................................................11
Introduction ................................................................................................................11
Review of Related Literature .....................................................................................13
Sample............................................................................................................13
Testing/Instruments........................................................................................14
Methodology/Treatment/Programs ................................................................15
Data Analysis .................................................................................................17
Conclusions/Recommendations .....................................................................19
Recommendations for Programs ................................................................................20
Sample............................................................................................................20
Testing/Instruments........................................................................................21
Methodology/Treatment/Programs ................................................................21
Data Analysis .................................................................................................21
Conclusions/Recommendations .....................................................................21
Summary of Literature Review ..................................................................................21
References ..................................................................................................................23
Chapter Three ..........................................................................................................25
Selection of the Topic ................................................................................................25
3
Time of Research .......................................................................................................25
Selection of the Sample .............................................................................................25
Description of the Instruments to be Used .................................................................25
Description of the Program/Intervention to be Used .................................................26
Tryout Procedures of the Instruments ........................................................................26
Collection of Data ......................................................................................................26
Table 3.1 ....................................................................................................................28
Analysis of Data .........................................................................................................29
Table 3.2 ....................................................................................................................30
References ..................................................................................................................33
Chapter Four ............................................................................................................31
Introduction ................................................................................................................31
Results ........................................................................................................................31
Table 4.1 ....................................................................................................................32
Table 4.2 ....................................................................................................................33
Discussion ..................................................................................................................34
References ..................................................................................................................35
Chapter Five .............................................................................................................36
Introduction ................................................................................................................36
Summary ....................................................................................................................36
Chapter One ...................................................................................................36
Chapter Two...................................................................................................37
Chapter Three.................................................................................................38
Chapter Four………………………………………………………………...39
Conclusions ................................................................................................................39
Recommendations ......................................................................................................39
References ..................................................................................................................40
Bibliography .............................................................................................................42
Appendix A ...............................................................................................................44
Appendix B ………………………………………………………………………...49
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CHAPTER ONE
THE PROBLEM
A. INTRODUCTION
There are four basic parts that physical fitness is composed of. The first part is
cardiovascular endurance. The second component is muscular endurance. Muscular strength is
the third component. The fourth and final component is flexibility. In order for a person to be
physically fit, he/she must have a certain level of each component of physical fitness.
Muscular strength is defined as the ability of the muscle to generate the maximum
amount of force (Sutton 2007). It can also be defined as the maximum amount of push or pull
that can be exerted one time by a muscle group (Battinelli 2000) and the amount of force that can
be generated by the musculature that is contracting (Morrow 2005). In the athletic setting,
muscular strength is a commonly used fitness measure for assessing the strength and power that
an individual athlete has (Hoffman 2006). In physiological terms, muscular strength is the
greatest number of muscle fibers that can be innervated at one time (Golding 2000). Muscular
strength can be determined by the size of the muscle and cross-section of the muscle, muscle
length and the angle of the pull, and by the muscle contraction speed and the amount of force
that is produced (Battinelli 2000).
Muscular strength can be measured in two different ways. One way that it can be
measured is through an isometric contraction (Hoffman 2006). This form of testing involves the
subject pushing or pulling on an immovable object. This type of testing is typically measured
with a dynamometer, strain gauge, load cell, or cable tensiometer (Golding 2000). The second
form of testing is a dynamic test. The most commonly used type of dynamic test is a one
maximum dynamic contraction test, or a one repetition maximum (1RM) (Golding 2000).
The definition of flexibility is the ability to move a joint through the full range of motion
without discomfort or pain (Sutton 2007). The role of flexibility in sport performance is not
clearly understood, but the lack of flexibility may predispose athletes to muscle and tendon
injuries (Hoffman 2006). One type of flexibility is static flexibility. Static flexibility is the
ability to stretch the body in different directions (Battinelli 2000). Another type of flexibility is
dynamic flexibility. This type of flexibility is the ability to make continuous rapid trunk and
5
limb movements (Battinelli 2000). The degree of flexibility is specific to each joint and is
generally limited by joint structure, movement dimension capacity, and the elasticity and
extensibility of muscle and connective tissue (Battinelli 2000).
Flexibility is expressed in a measure relative to the joint (Gore 2000). Flexibility can be
measured using a flexometer and an inclinometer (Hoffman 2006). It can also be measured
using goniometry, visual estimation, radiography, photography, linear measurements, and
trigonometry (Morrow 2005). Since flexibility is specific to a specific joint and the tissues
surrounding it, there is no valid test for general flexibility (Morrow 2005).
B. PURPOSE OF THE STUDY
The major purpose of this study was to determine a correlation between an individual’s
muscular strength and flexibility.
C. STATEMENT OF THE PROBLEM
The study was designed to answer the following question:
1. Was there a correlation between an individual’s muscular strength and flexibility?
D. HYPOTHESIS OF THE STUDY
The null hypothesis for this research was as follows:
There was no correlation between an individual’s muscular strength and flexibility.
E. NEED FOR THE STUDY
Physical fitness is an important aspect of life because it has many health related benefits.
Research has shown that moderate daily physical activity can substantially reduce the risk of
developing or dying from certain diseases such as cardiovascular disease, type II diabetes, and
certain cancers. Daily physical activity can also help decrease blood pressure, lower cholesterol,
reduce obesity, prevent and slow down osteoporosis, and decrease the symptoms of arthritis.
Symptoms of anxiety and depression can also be affected by moderate physical activity (Physical
2008). These are all reasons it is important to be physically active. It is reported that 37 percent
of adults say that they are not physically active (Physical 2008).
6
Physical Fitness is defined as “a set of attributes that people have or achieve that relates
to the ability to perform physical activity” (Components 2008). There are four basic components
that make up physical fitness. These components are cardiovascular endurance, muscular
strength, muscular endurance, and flexibility (Sutton 2007). Some texts also include body
composition as an added component of physical fitness (Components 2008).
Muscular strength is maximum push or pull that can be exerted one time by a muscle
group (Golding 2000). To gain muscular strength an individual partakes in a strength training
program. Strength training involves doing exercises with hand weights, elastic bands, or weight
machines to build muscle mass (Sutton 2007). One common test for muscular strength is the one
repetition maximum test (Battinelli 2000). Benefits of strength training include arthritis relief,
restoration of balance, strengthening of bone, weight maintenance, and glucose control (Sutton
2007).
Flexibility is defined as the ability to move a joint through the full range of motion
without discomfort or pain (Sutton 2007). Flexibility can be improved through flexibility
training and regular stretching. Flexibility training can include such activities as yoga and pilates
(Sutton 2007). Flexibility is increased by doing activities that lengthen the muscles. Having the
proper amount of flexibility in the joints can help to prevent getting injuries through all stages of
life (Components 2008).
Since muscular strength and flexibility are both components of physical fitness, it is
important to maximize each one. This study was beneficial to the subjects and the professional
world because it allowed them to see the correlation between muscular strength and flexibility.
By determining the correlation between the two, information can be provided on how much
flexibility is dependant on muscular strength and visa versa.
F. DELIMITATIONS OF THE STUDY
The major delimitations of the study were:
1.
All the subjects were volunteers.
2. All the subjects were students at a university in Southeast Tennessee.
3. All subjects were tested in a class designed specifically for research testing.
4. The tests were taken in the 2007 school year.
5. All subjects were between the ages of 18-38.
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6. The strength test was delimited to the one repetition max.
G. LIMITATIONS OF THE STUDY
The major limitations of the study were:
1. The researcher was not the one who collected the data.
2. There were multiple testers.
3. The researcher was not present when the tests were taken.
4. All testers may not have been using exactly the same joint reference points when
calculating range of motion.
5. Goniometry is not the most accurate form of determining flexibility.
H. BASIC ASSUMPTIONS
On the basis of the delimitations and limitations, several major assumptions were made
relative to the study. They were:
1. It was assumed that all testers were instructed correctly by the researcher.
2. It was assumed that the correct instructions were given during the tests.
3. It was assumed that the results were recorded correctly.
4. It was assumed that proper form was used during the one repetition maximum bench
press test.
5. It was assumed that the volunteers were willing to fully participate in the study.
I. DEFINITIONS AND INTERPRETATIONS
Definitions:
1. Muscular strength: the ability of the muscle to generate the maximum amount of force
(Sutton 2007).
2. Flexibility: the ability to move a joint through the full range of motion without
discomfort or pain (Sutton 2007).
3. Physical fitness: a set of attributes that people have or achieve that relates to the ability
to perform physical activity (Components 2008).
4. Goniometry: the measuring of the angle that is created by the bones of the body at the
joint (Guide 2001).
8
5. Cardiovascular endurance: the ability of the individual’s cardiovascular system and the
respiratory system to supply oxygen during sustained physical activity (Definitions 2000)
6. Muscular endurance: the muscles ability to continue to perform without fatigue
(Definitions 2000).
7. Body composition: the relative amounts of muscle, bone, fat, and other vital body parts
(Definitions 2000).
Interpretations:
1. 1RM: the one repetition maximum test is a test that causes the individual to use their
maximum effort for one repetition.
9
REFERENCES
Battinelli, Thomas. 2000. Pyhsicque, Fitness, and Performance. New York, NY: CRC Press.
Center for Disease Control and Prevention. 2008. “Components of Physical Fitness.”
http://www.cdc.gov/nccdphp/dnpa/physical/components/.
Golding, Lawrence (ed.). 2000. YMCA Fitness Testing and Assessment Manual. 4th ed.
Gore, Christopher. 2000. Physiological Tests for Elite Athletes. Champaign, IL: Human
Kinetics.
Hoffman, J. 2006. Norms for Fitness, Performance, and Health. Champaign, IL: Human
Kinetics.
Lock Haven University of Pennsylvania. 2001. A Guide to Manual Muscle Testing and
Goniometry.
http://www.lhup.edu/yingram/jennifer/webpage/introduction_to_goniometry.htm.
Morrow, J., Jackson, A., Disch, J., Mood, D. 2005. Measurement and Evaluation in Human
Performance. Champaign, IL: Human Kinetics.
The President’s Council on Physical Fitness and Sports. 2000. Definitions: Health, Fitness, and
Physical Activity. http://www.fitness.gov/digest_mar2000htm.
The President’s Council on Physical Fitness and Sports. 2008. “Physical Activity Facts.”
http://www.fitness.gov/resources_factsheet.htm.
Sutton, Amy (ed). 2007. Fitness and Exercise Sourcebook. Detroit, MI: Omnigraphics, Inc.
10
CHAPTER TWO
REVIEW OF RELATED LITERATURE
A. INTRODUCTION
Physical fitness is defined as a set of attributes that people have or achieve that
relates to the ability to perform physical activity (Components 2008). It has also been defined as
a state of well-being that includes low risk of premature health problems and energy to
participate in a variety of physical activities (Definitions 2000). There are four different
components of physical fitness. These components include cardiovascular endurance, muscular
endurance, muscular strength, and flexibility (Sutton 2007). Some texts also include body
composition as the fifth component of physical fitness. In order for an individual to be
considered physically fit, he/she must maintain a certain level of each of these components
(Components 2008).
The first component of physical fitness is cardiovascular endurance. Cardiovascular
endurance is related to the ability of the individual’s cardiovascular system and the respiratory
system to supply oxygen during sustained physical activity. This component can be measured by
performing a VO2Max test (Definitions 2000). The next component is muscular endurance. The
term muscular endurance relates to the muscles ability to continue to perform without fatigue.
This can be measured by performing as many repetitions as possible for a given muscle group
(Definition 2000). Body composition is referred to as the relative amounts of muscle, bone, fat,
and other vital body parts (Definitions 2000).
The next component of physical fitness is muscular strength. Muscular strength is
defined as the ability of the muscle to generate the maximum amount of force (Sutton 2007). It
can also be defined as the maximum amount of push or pull that can be exerted one time by a
muscle group (Battinelli 2000) as well as the amount of force that can be generated by the
musculature that is contracting (Morrow 2005). When looking at it from the physiological
aspect, muscular strength is the greatest number of muscle fibers that can be innervated at one
time (Golding 2000). Muscular strength can be determined by the size and cross-section of the
muscle. It can also be determined by the length of the muscle and the angle of the pull and by the
muscle contraction speed and the amount of force that is produced by the contraction (Battinelli
11
2000). When referring to sports, muscular strength is a commonly used fitness measure for
assessing the strength and power that an individual athlete has (Hoffman 2006).
There are two different ways muscular strength can be measured. One way that muscular
strength can be measured is through an isometric contraction (Hoffman 2006). An isometric
contraction is a type of muscle contraction in which the length of the muscle stays the same but
the tension increases. This form of testing involves the subject pushing or pulling on an
immovable object. The instruments that are typically used to measure this type of test include
the dynamometer, strain gauge, load cell, or cable tensiometer (Golding 2000). The second form
of measuring muscular strength is using a dynamic test. This type of testing deals with an
isotonic contraction. An isotonic contraction is a contraction in which the tension on the muscle
is constant but the length of the muscle is changing. The most commonly used type of dynamic
test is a one maximum dynamic contraction test, or a one repetition maximum (1RM) (Golding
2000).
The final component of physical fitness is flexibility. Flexibility is defined as the ability
to move a joint through the full range of motion without discomfort or pain (2007). There are
different types of flexibility. The first type of flexibility is static flexibility. Static flexibility is
the ability to stretch the body in different directions (Battinelli 2000). A second type of
flexibility is dynamic flexibility. This type of flexibility relates to the ability to make continuous
rapid trunk and limb movements (Battinelli 2000). The degree of flexibility is specific to each
joint. Flexibility is generally limited by joint structure, movement dimension capacity, and the
elasticity and extensibility of the muscle and connective tissue (Battinelli 2000). The role of
flexibility in sport performance is not clearly understood, but the lack of flexibility may
predispose athletes to muscle and tendon injuries (Hoffman 2006).
Flexibility is expressed in a measure that is relative to the joint (Gore 2000). There are
many different devices that can be used to measure flexibility. Flexibility can be measured using
a flexometer or an inclinometer. Flexometers and inclinometers are devices that use gravity to
help determine the angle at which the joint is positioned (Hoffman 2006). Flexibility can also be
measured using goniometry, visual estimation, radiography, photography, linear measurements,
and trigonometry. Radiography is the most reliable and valid method of measuring flexibility,
but this method has limited feasibility. Goniometry is the most feasible form of measuring
flexibility. It can be very reliable and valid if proper test procedures are followed (Morrow
12
2005). Goniometry is the measuring of the angle that is created by the bones of the body at the
joints. Goniometry is measured using a goniometer. A goniometer is a device that consists of a
moving arm, a stationary arm, and a fulcrum. The fulcrum has a scale that ranges from 0 to 180
degrees. The fulcrum is placed over the joint that is being measured. The stationary arm is
aligned with the part of the joint that is not being moved. The moving arm is placed over the
part of the limb that will be changing its position. The degree of flexibility is then read from the
scale on the fulcrum (Guide 2001). Since flexibility is specific to a specific joint and the tissues
that are surrounding it, there is no valid test for general flexibility (Morrow 2005).
B. REVIEW OF RELATED LITERATURE
SAMPLE
In the Behm et al (2005) study, two different groups were used. The first group was a
convenience group that consisted of nine men and nine women. These men and women had a
mean age of 25 ± 8.3 years, a mean height of 1.68 ± 0.93 meters, and a mean body mass of 73.5
± 14.4 kg. The second group consisted of twelve men who were not actively engaged in
flexibility training. This group had a mean age of 21.9 ± 2.1 years, a mean height of 1.77 ± 0.11
meters, and a mean body mass of 79.8 ± 12.4 kg. All of the participants in this study were from
the university student population. Each participant completed a Physical Activity Readiness
Questionnaire form to indicate that they have no significant health problems.
The Halvorson (2007) study included thirty participants. The participants were
“apparently healthy and injury free” cadets at the United States Military Academy. All
participants were current members of rugby, lacrosse, or strength and conditioning teams.
The Kokkonen and Nelson (2001) study consisted of 11 females and 11 males. These
participants were college students enrolled in professional physical education classes and were
not engaged in any regular or organized stretching or weight lifting activity.
The Kravitz (2006) study consisted of 43 healthy subjects. There were 15 female and 28
male participants, all of which were sedentary for at least six months prior to the start of the
study.
The Nelson et al (Acute, 2005) study consisted of eleven males with a mean age of 21 ± 2
years with an average mass of 77.0 ± 6.8 kg, and five females with a mean age of 19 ± 1 years
13
with an average mass of 67.6 ± 6.8kg. All subjects were members of Louisiana State
University’s track and field team and had practiced sprint starts almost daily for at least two
years.
The Nelson et al (2001) study consisted of 30 males and 25 females. All participants
were college students who were enrolled in professional physical education classes and were free
of any history of knee problems.
The Nelson et al (Strength, 2005) study consisted of 18 women and 13 men. All of the
participants were college students enrolled in physical fitness classes and had engaged in at least
30 minutes of supervised and organized daily stretching for at least the 10 weeks prior to the
study. All participants had a percentile rank greater than 60 for the sit-and-reach norms.
The Siegel (2006) study consisted of 11 males and 11 females. All participants were
college students.
The Tsuang et al (2007) study consisted of 12 New Zealand White rabbits. All rabbits
were four months old and had a mean weight of 2.5kg.
The Cornelius and Hands (1992) study consisted of 54 physically active, healthy, females
from the Downtown Dallas, TX, YMCA. The subjects were between the ages of 23 and 38 and
had no known injuries or disabilities to the hip and legs, and were within normal percent body fat
limits.
TESTING/INSTRUMENTS
In the Behm et al (2005) study the sit and reach test was used to calculate low back
flexibility. The study used hip flexion and hip extension tests and also a plantar flexiondorsiflexion test, which were all measured with a goniometer. A Wheatstone bridge
configuration strain gauge was used for the knee extension and flexion measures in this study.
The Behm et al study used a contact mat that was imbedded with a timer switch to calculate the
contact time and jump height during the drop jump tests and the countermovement jump tests.
In the Halvorson (2007) study, the researcher used three tests to measure performance.
The 5-step jump was used to assess leg power. The medicine ball distance throw was used to
measure total-body power. Finally the T-drill was used to measure agility.
In the Kokkonen and Nelson (2001) study, the researchers used an Acuflex I sit-andreach box to test low back flexibility. The researchers also used the Nautilus knee-flexion and
the Nautilus knee-extension machine to test the one repetition maximum (1RM).
14
The Kravitz (2006) study used the Flexitest to assess the flexibility of the subjects. This
study also used the 1RM to test muscular strength on the leg press and bench press.
The Nelson et al (Acute, 2005) study used an automated timer that utilized a pressure pad
that started the timer when pressure was released and stopped when the runner broke a laser light
beam 20 meters down the track.
The Nelson et al (2001) study used a Cybex II isokinetic device at five different angles to
measure isometric torque.
The Nelson et al (Strength, 2005) study used the Acuflex I sit-and-reach flexibility tester.
The study also used the Nautilus knee-flexion and knee-extension machines to test 1RM.
The Siegel (2006) study used a Nautilus knee-extension machine to perform and
endurance test. A sit-and-reach test was also used in this study.
In the Tsuang et al (2007) study, dial calipers accurate to 0.05mm was used to measure
the distance between the origin of the triceps surae at the distal femur and the insertion site at
calcaneus. The researchers also used electrical stimulating devices to produce muscle
contractions.
The Cornelius and Hands (1992) study used the Lange Skinfold Calipers to do a threesite body fat analysis prior to flexibility testing. The study used a whirlpool for the passive
warm-up and a Schwinn DX-9 Stationary Cycle for the active warm-up. Knee extension ROM
was test using the Leighton Flexometer.
METHODOLOGY/TREATMENT/PROGRAMS
The Behm et al (2005) study was designed to test the hypothesis that individuals that had
a greater range of motion (ROM) in the correlation study or those who gained a greater ROM
with flexibility training would experience less stretch-induced deficits in force or power. A
cross-sectional correlation study tested ROM associated with hip flexion, hip extension, and
plantar flexion-dorsiflexion. Subjects were tested both before and after an acute session of static
stretching for knee extension force and drop jump performance. A second experiment was a
longitudinal repeated measures design that tested knee extension and flexion forces, drop jump
performance, and countermovement vertical jump before and after an acute session of stretching.
These subjects participated in a five day per week, four week flexibility training program and
then performed a post test.
15
The Halvorson (2007) study was conducted to determine whether static-stretching or
dynamic warm-ups were more beneficial for increased exercise performance. The participants
were broken into three groups: dynamic warm-up, static-stretching warm-up, and no warm-up.
The dynamic warm-up group participated in ten repetitions of low cadence exercises while the
static-stretching group performed 20-30 seconds of static stretches. Each session lasted ten
minutes. After the warm-up sessions, each group was tested with in the 5-step jump, the
medicine ball distance throw, and the T-drill.
The Kokkonen and Nelson (2201) study was conducted to determine the performance
difference after ballistic stretching. Participants were tested in knee flexion and knee extension
1RM following either ten minutes of not stretching or twenty minutes of active and passive
ballistic stretching. The sit-and-reach test was also conducted to determine if alterations of joint
ROM occurred fallowing the stretching/non stretching session.
The purpose of the Kravitz (2006) study was to answer questions about the flexibilitystrength interaction on muscle performance and joint ROM. Volunteers went through a 12-week
study with each week consisting of two training sessions separated by two days of rest. Subjects
were placed into four different groups: flexibility, resistance training, flexibility and resistance
training, and a control group of subjects that remained sedentary. The flexibility group and
combined group did stretches that were held at maximal range for 30 seconds for a total of three
times. The resistance training program had the subjects perform 3 sets of 8-12 repetitions.
The Nelson et al (Acute, 2005) study used four different stretching protocols over a four
week period. The stretching protocols were no stretch of either leg, both legs stretched, forward
leg in starting position stretched, and rear leg in the starting position stretched. The stretches
included a hamstring stretch, a stretch in which the leg was in the vertical position with the ankle
dorsiflexed, and Alter’s stretch number 196. Stretches were maintained for 30 seconds. The
athletes then did 20 meter sprints with a minimum of one minute recovery between each.
The Nelson et al (2001) study had the participants do a baseline test of isometric torque at
the beginning of the session. The subjects did four maximal measurements at each of five
different angles. The stretching program consisted of two passive, static stretches of the
quadriceps muscle group. Stretches included the Alter exercise #91 and #93. The subjects were
then tested again.
16
The Nelson et al (Strength, 2005) study used a stretching program that consisted of 15
different static stretches that were designed to stretch all of the major lower extremity muscles.
When tested, the subjects did a 1RM test for knee extension and flexion following either 10
minutes of not stretching or 20 minutes of active and passive static stretching. The subjects also
did a sit-and-reach test before and after each treatment.
The Siegel (2006) study used two groups: a pretest stretching protocol group that
performed passive static stretching of the hip, thigh, and calf muscles and a group that engages in
ten minutes of not stretching. The subjects did leg flexion and extension endurance tests, in
which they served as their own controls. A sit-and-reach test was performed before and after the
experimental and control conditions.
The Tsuang et al (2007) study used two limbs of the rabbits. One limb used as the
control group was stretched until failure. The other limb used as the study group was subjected
to isokinetic and eccentric cyclic loading to 110% or 120% of its initial length for one hour.
These limbs were then stretched to failure. The study compared load-deformation curves and
biomechanical parameters between the two study groups.
The Conrelius and Hands (1992) study used three groups: a passive warm-up group, an
active warm-up group, and a no warm-up group. Each group participated in the assigned
treatment for 20 minutes and performed no stretching exercises before or during their warm-up.
Subjects were tested for hip ROM with knee extension.
DATA ANALYSIS
Behm et al (2005) established that in the cross-sectional study there was a -6.5% deficit
between pre- and post-stretch knee extension force output. Drop jump contact time increased by
5.4% between pre- and post-stretch measures, but there was no significant changes in drop jump
height. In the longitudinal study, there was an increase in sit and reach, hip extension, and hip
flexion ROM following the four weeks of flexibility training. Before the flexibility training
program, acute stretching caused -8.2% deficit in knee extension force, -6.6% in knee flexion
force, a 7.4% increase in drop jump time, and -5.7% in countermovement jump height. There
were no significant changes in drop jump height. When tested after the flexibility training
program there was a -6.1% deficit for knee extension force, -10.7% for knee flexion, -5.5% for
countermovement jump height, and a non significant increase in drop jump contact time and
height.
17
The data of the Halvorson (2007) study showed an improvement of the dynamic warm-up
group over the other two groups in all three tests. The test showed little difference between the
static-stretching warm-up group and the no warm-up group in the T-drill and the medicine ball
throw. However, the static-stretching group outperformed the no warm-up group in the 5-step
jump.
The 1RM and sit-and reach measurements in the Kokkonen and Nelson (2001) study
were analyzed using paired t tests with a level of significance set at p<.05. The data shows that
the sit-and-reach scores of the stretching group increased 9%, whereas the non stretching group
had no significant change in performance. The knee-flexion and knee-extension 1RM were
significantly less than those of the non stretching group, decreasing by an average of 7.5% and
5.6%.
In the Kravitz (2006) study, the global flexibility scores from the Flexitest increased in
response to flexibility training alone. Flexibility also increased when flexibility training was
combined with resistance training. The data also shows that resistance training alone had no
significant effect on improving flexibility.
In the Nelson et al (Acute, 2005) study, the three 20 meter times for each stretch
condition was calculated using an intraclass correlation coefficient. The mean average was taken
for each stretching condition and a one-way analysis of variance was used to compare the times.
The data show that there were no significant differences between any of the four days. The data
also show that there was no the three stretching conditions had significantly slower times than
the no-stretch condition.
The data from Nelson et al (2001) show that the torque following the stretching exercises
was not significantly different from the pre-stretch values, except for at the joint angle of 162o.
At 162 o, the average torque was 7% less than the pre-stretch value.
The Nelson et al (Strength 2005) study produced data that show the stretching session
increased sit-and-reach by 6% and the non-stretching session had no significant effect. The data
show that flexion and extension 1RM was significantly after stretching than non-stretching.
The data from the Siegel (2006) study a significant improvement in pre to post sit-andreach measures for the subjects who stretched and no difference for the ones who did not. The
subjects that stretched prior to the endurance task experienced a 24.4% reduction in performance
in the endurance test.
18
The Tsuang et al (2007) study data show that when the muscles received eccentric cyclic
loading to 112% the parameters were not significantly changed. However, it shows that most of
the parameters were significantly decreased after isokinetic eccentric cyclic loading to 120%.
The Cornelius and Hands (1992) study data show that there were no significant
differences between the conditions of the warm-up.
CONCLUSIONS/RECOMMENDATIONS
The Behm et al (2005) study determined that an individual’s initial level of joint ROM
was not correlated with stretch-induced deficits. The study also concluded that four weeks of
flexibility training did not diminish stretch-induced impairments. The researchers stated that
there have been many studies that demonstrate decreases in isometric force, dynamic strength,
and jump height following an acute bout of static stretching, but there have been no studies that
report on the effect of greater joint ROM or flexibility training on stretch-induced impairments.
The study also reported that the addition of flexibility exercises to a 13-week strength-training
program had no significant effect on the strength training responses.
The Halvorson (2007) concludes that a dynamic warm-up is more beneficial than a staticstretching warm-up or no warm-up at all. The researcher theorizes that the decreased
performance following static-stretching could be due to the diminishing of neural activity during
static warm-ups, but does not conclude on this statement because neural activation was not tested
in this study. The researcher also says that in theory the static-stretching could cause tendon
slack that could inhibit power output.
The Kokkonen and Nelson (2001) study concluded that there was a significant decrease
in 1RM performance for both knee flexion and knee extension following an acute ballistic
stretching treatment. The researchers also conclude that regimens of acute ballistic stretching
can inhibit the maximal strength of the knee flexors and extensors.
The Kravitz (2006) study comes to the conclusion that resistance training has no
independent influence on improving flexibility training. A combined program of resistance
training and flexibility training produced “positive and meaningful” enhancements in both the
resistance and flexibility components.
Nelson et al (Acute, 2005) concluded that the time of a 20 meter sprint was significantly
increased when the sprints were performed after stretching. The study says that skills that
require multiple repetitive high power outputs may be negatively impacted by pre-performance
19
stretching. The study also says that stretching just one leg for activities that use both legs is
sufficient in adversely affecting performance.
The study by Nelson et al (2001) concluded that a significant decrease in maximal
voluntary isometric torque at knee angle of 162o suggests that a force decrement is more
apparent at an angle that is closer to full extension. This study supports the supposition that a
thorough bout of acute stretching can inhibit strength because it places the sarcomeres at a less
than optimal length. It also suggests that the negative impact is much greater in activities that
require the joint to work in the terminal position of its ROM.
The Nelson et al (Strength, 2005) study concluded that, in individuals who had
consistently performed stretching exercises for at least 10 weeks, individuals with greater
stretching experience had a significant decrease in 1RM performance for both knee flexion and
knee extension following acute static stretching. It states that acute stretching can inhibit
maximal strength of knee flexion and extension regardless of the individual’s stretching history.
The Siegel (2006) study concluded that endurance performance in decreased following
pre-endurance test stretching. It theorizes that the reduction could be caused by neuronal fatigue,
reduced muscle stiffness reducing force transmission, impaired blood flow to muscles, and an
influx of calcium in the muscle cells.
The Tsuang et al (2007) study concludes that eccentric exercise may induce changes in
the biomechanical properties of skeletal muscles. This is true even within the physiological
range of the excursion of the muscle-tendon unit.
The Cornelius and Hands (1992) study concludes that the modified proprioceptive
neuromuscular facilitation stretching technique can be very effective for athletes who are
attempting to increase ROM of their joints. It concludes that even though this technique requires
more time and supervision, there are no scientifically substantiated techniques that provide a
greater ROM than the modified proprioceptive neuromuscular facilitation procedures.
C. RECOMMENDATION FOR PROGRAMS
SAMPLE
The majority of the studies reviewed used a sample consisting of college age students.
Most of the studies included a mixture of male and female participants. Many of the studies used
participants that were not regularly involved in flexibility or strength training activities. The
20
number of subjects ranged from 16 to 55. One study reviewed used all women, another all men,
and one study used rabbits as subjects.
TESTING/INSTRUMENTS
In the studies reviewed, the instruments that were used to measure range of motion were
the goniometer and a flexometer. Some of the studies used the sit-and-reach test to measure
flexibility. In these studies the researchers used the Flexitest and an Acuflex I sit-and-reach box.
The majority of the tests used some form of knee flexion and extension machine to calculate the
one repetition maximums. Other instruments used were the Wheatstone bridge configuration
strain gauge and a Cybex II isokinetic device.
METHODOLOGY/TREATMENT/PROGRAM
The majority of the studies reviewed were concerned with the effects of pre-event
stretching on the exercise performance. The studies would have the subjects perform certain
forms of stretching before being given a test to determine force, speed, or flexibility. These
studies used comparisons to pre-program totals and post-program totals and also compared
groups that were given different stretching programs over a given amount of time.
DATA ANALYSIS
The majority of the studies reviewed used ratios between a control group and the group
that partook in a stretching program. These studies also analyzed ratios between the different
forms of stretching techniques. The paired t test was the most common form of data analysis
used to provide the ratios between the tests.
CONCLUSIONS/RECOMMENDATIONS
The majority of the studies reviewed concluded that pre-event stretching caused a deficit
in the exercise performance of the participants. Pre-event stretching caused a decrease in power
output. The studies also concluded that dynamic warm-ups were more beneficial than static
stretching warm-ups and that the addition of flexibility to a strength-training program had no
significant effect on the strength training responses.
D. SUMMARY OF LITERATURE REVIEW
The literature review covered studies ranging from those that looked at the affects of preevent stretching in college aged students to those that looked at the affects of eccentric exercises
on the biomechanical parameter and load-deformation in rabbits. After reviewing the literature,
21
the investigator learned that pre-event stretching has a negative effect on the exercise
performance in terms of speed, agility, and power output. Most of the samples were taken from
college age students who were mostly physically inactive. The studies had the participants
perform different forms of pre-event stretching and then they were tested on some form of
performance test. The majority of the researchers used goniometers and sit-and-reach
measurements to calculate range of motion and flexibility. Most of the researchers also used
some form of machine or a one repetition maximum test to calculate the amount of force the
subject could produce.
22
REFERENCES
Behm, D.G., E. E. Bradbury, A. T. Haynes, J. N. Hodder, A. M. Leonard, N. R. Paddock, et al.
2005. Flexibility is not Related to Stretch-Induced Deficits in Force or Power. Journal of
Sports Science and Medicine, 5: 33-42.
Cornelius, W., M. Hands. 1992. The Effects of a Warm-up on Acute Hip Joint Flexibility Using
a Modified PNF Stretching Technique. Journal of Athletic Training :112-114.
Halvorson, R., et al. 2007. Dynamic Warm-Ups Improve Athletic Performance. IDEA Fitness
Journal: 19.
Kokkonen, J., A. G. Nelson, et al. 2001. Acute Ballistic Muscle Stretching Inhibits Maximal
Strength Performance. Research Quarterly for Exercise and Sport, 72(4): 415-419.
Kravitz, L., et al. 2006. Resistance and Flexibility Training: an Ambiguous Relationship
Clarified. IDEA Fitness Journal: 23-25.
Nelson, A., N. Driscoll, D. Landin, M. Young, I. Schexnayder, et al. 2005. Acute Effects of
Passive Muscle Stretching on Sprint Performance. Journal of Sports Sciences, 23(5): 449454.
Nelson, A., J. Allen, A. Cornwell, J. Kokkonen, et al. 2001. Inhibition of Maximal Voluntary
Isometric Torque Production by Acute Stretching is Joint-Angle Specific. Research
Quarterly for Exercise and Sport, 72(1): 68-70.
Nelson, A., J. Kokkonen, C. Eldredge, et al. 2005. Strength Inhibition Following an Acute
Stretch is Not Limited to Novice Stretchers. Research Quarterly for Exercise and Sport,
76(4): 500-506.
Siegel, D. (ed.), et al. 2006. Stretching and Muscular Endurance Performance. JOPERD, 77(5):
5.
23
Tsuang, Y., S. Lam, L. Wu, C. Chiang, L. Chen, P. Chen, J. Sun, C. Wang, et al. 2007.
Isokinetic Eccentric Exercise can Induce Skeletal Muscle Injury within the Physiologic
Excursion of Muscle-Tendon Unit: a Rabbit Model. Journal of Orthopedic Surgery and
Research, 2(13): 1-7.
24
CHAPTER THREE
METHODOLOGY
A. SELECTION OF TOPIC
Muscular strength and flexibility are two of the categories that make up physical fitness.
The concern of this study was to determine if there was a correlation between an individual’s
muscular strength and flexibility. The sample the researcher has chosen is represented by male
college aged students who were attending a major metropolitan university. The researcher chose
this study because he is interested in strength training and gaining muscle mass but is concerned
about the effects of the increase in muscle mass diminishing the level of flexibility.
B. TIME OF RESEARCH
The topic for this study was chosen January 9, 2008 and approved on January 11, 2008.
Literature review for this study started January 11, 2008.
The samples were chosen in the Fall semester of 2007.
Gathering data for this study occurred in the Fall semester of 2007.
The testing was conducted in the Fall school semester of 2007.
Analyzing data for this study started March 5, 2008.
Data analysis for this study was completed
Research for this study was completed
C. SELECTION OF THE SAMPLE
The data for this study were collected in the fall semester of the 2007-2008 school year.
Samples chosen by the main researcher were from both genders. The subjects for this study were
all males and were between 18-38 years old. The subjects were all students attending a major
metropolitan university. The subjects were chosen randomly by the students of an exercise
testing class. All other information regarding the subjects was considered private and was not
disclosed by the main researcher.
D. DESCRIPTION OF THE INSTRUMENTS TO BE USED
25
The instrument used to determine the flexibility of the subjects was a goniometer. The
goniometer is used to measure the angle that is created by the bones of the body at the joints.
The goniometer consists of a moving arm, a stationary arm, and a fulcrum. On the fulcrum is a
scale that ranges from 0 to 180 degrees. To use the goniometer, the fulcrum is placed over the
joint that is going to be measured. The stationary arm is then aligned with the side of the joint
that is not going to be moved. The moving arm is them placed over the part of the limb that will
be changing position. Once the joint is at the end of the range of motion, the degree of flexibility
is read from the scale on the fulcrum.
The test that was used to determine muscular strength was the one repetition maximum
(1RM) bench press. This test involves the subject lifting the most weight they can for one
repetition. The subject starts with a weight close to what they think is the most that they can do.
The subject then increased the weight and performed the movement again. This process was
repeated until the subject tried to lift a weight that they could not successfully perform. The
weight completed before the failed weight was the subjects 1RM.
E. DESCRIPTION OF THE PROGRAM/INTERVENTION TO BE USED
There was no program or intervention used in this study.
F. TRYOUT PROCEDURES OF THE INSTRUMENTS
During the trial procedure the instructor taught the testers how to use the goniometer.
The instructor showed the testers how to place the arms and the fulcrum over the joint. The
instructor then showed the testers how to have the subject move the joint through the full range
of motion and how to move the arm of the goniometer with the body part. The instructor then
taught the testers how to read and record the degree of flexibility from the scale on the
goniometer. Following the block of instructions, the testers practiced taking flexibility
measurements on one another.
G. COLLECTION OF DATA
The total number of subjects was not disclosed to the researcher. Both male and female
subjects participated in the research. For this particular study, only the scores for the male
subjects attending the major metropolitan university were provided.
26
The testing was done randomly at no certain time of the day. All measurements were
taken with a goniometer in the right shoulder. The movement that was measured was shoulder
abduction. Each measurement was taken twice and the average of the two degrees was taken and
recorded.
The following table is a sample showing the comparison of the male subject’s, between
the ages of 18-38, one repetition maximum bench press and flexibility.
27
Table 3.1
Subjects’ One Repetition Max vs. Flexibility
Ss
Age
1RM
Flexibility__________
1
2
3
k
Legend:
Ss= Subjects
Age= The age of the subjects at the time of testing
1RM= One repetition maximum bench press in pounds
Flexibility= Degree of shoulder range of motion.
28
H. ANALYSIS OF DATA
The independent variable in this study was the subjects’ strength that was determined by
the one repetition maximum test. The dependent variable for this study was the subjects’
shoulder flexibility. The Spearman r was used to analyze the date. The strength and flexibility
scores for given ranks so that they could be compared. This made the date nonparametric.
Therefore the Spearman r was used to determine a correlation between ordinal level data.
The following table is a sample showing the results of the statistical analysis of the study.
29
Table 3.2
Statistical Analysis
Level of Confidence
Degree of Freedom
Critical Value
Calculated Value
Legend:
Level of Confidence= p>0.05
Degree of Freedom= the number of subjects minus one
Critical Value= a value in the sample distribution to which the calculated statistic was compared
Calculated Value= a value derived from computing procedures applied to the data
30
CHAPTER FOUR
RESULTS OF THE STUDY
A. INTRODUCTION
This chapter will describe the results of this study. This study looked at muscular
strength and flexibility to determine if a correlation existed. The test used for muscular strength
was the one repetition maximum bench press. For this test the subject performed a bench press
at increasing weights until the maximum weight the subject could lift was found. Flexibility was
tested using a goniometer and was taken at the right shoulder. The movement that was tested
was shoulder abduction. The data from these tests were analyzed using the Spearman r two
tailed test. The null hypothesis was accepted based on the results of the data analysis.
B. RESULTS
Table 4.1 shows the raw scores of the males’ one repetition maximum bench press and
the range of motion for the right shoulder abduction. The one repetition maximum scores were
recorded as the maximum weight in pounds that the subject lifted. The range of motion was
recorded as the total number of degrees the joint moved. Table 4.2 shows the statistical analysis
from the SPSS 15 program. Table 4.2 shows that the calculated value falls inside the parameters
of the critical value, thus the null hypothesis was accepted.
31
Table 4.1
Subjects’ One Repetition Max vs. Flexibility
Ss
Age
1RM Flexibility
Ss
Age
1RM Flexibility
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
22
23
19
23
21
21
21
22
20
20
22
31
20
38
19
21
32
24
25
28
24
30
22
24
19
20
23
20
22
23
25
22
22
18
20
415
365
265
405
395
215
225
185
190
250
145
175
195
245
255
225
225
215
225
295
185
205
175
185
125
130
195
205
205
160
320
185
250
145
315
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
36
24
26
22
33
23
23
27
22
19
21
18
18
21
20
20
23
21
26
21
25
22
22
19
180
175
215
250
255
225
145
165
205
135
285
205
205
160
125
140
160
165
180
185
145
155
195
175
180
180
180
180
168
180
180
150
120
138
110
183
162
154
183
170
186
182
180
184
182
182
190
182
180
179
171
173
169
186
145
167
168
178
182
152
189
174
180
177
160
179
178
181
180
196
177
185
182
180
188
180
180
180
180
180
180
180
180
Legend:
Ss= Subjects
Age= The age of the subjects at the time of testing
1RM= One repetition maximum bench press in pounds
Flexibility= Degree of shoulder range of motion.
32
Table 4.2
Spearman r Data Analysis of Strength and Flexibility Correlation
Level of Confidence
0.05
Degree of Freedom
58
Critical Value
.250
Calculated Value
.010
Legend:
Level of Confidence= p>0.05
Degree of Freedom= the number of subjects minus one
Critical Value= a value in the sample distribution to which the calculated statistic was compared
Calculated Value= a value derived from computing procedures applied to the data
33
C. DISCUSSION
The results of this study show that there is no correlation between muscular strength and
flexibility. The results indicate that the amount of weight that a male between the ages of 18-38
is able to lift during a one repetition bench press has no relation to the shoulder abduction range
of motion. The majority of the studies that were reviewed for this research concluded that
stretching before an activity caused a decrease in the amount of power that was produced by that
muscle group. The Behm et al (2005) study concluded that when flexibility exercises were
added to a 13-week strength training program it had no significant effect on the strength training
responses. The Kravitz (2006) study concluded that resistance training had no independent
influence on the improvement of flexibility training, but a combined program of resistance and
flexibility training could produce enhancements in both components.
Limitations to this study should be taken into account when stating that this study
accepted the null hypothesis. One limitation was that the testers were not professionals at using
the goniometer. For some of the testers, this study was the first or second experience in taking
range of motion measurements with a goniometer.
The fact that there were multiple
inexperienced testers indicates that the measurements may not have been taken the same way
from one tester to the other. Another limitation to this study was the use of goniometry instead
of a more accurate form of determining range of motion. Goniometery was used because it is
inexpensive and more practical for the purpose of this study. For more accurate and precise
scores a different type of measurement process could be used. When reviewing the research
articles for this study the researcher concludes that it is possible that if the subjects stretched the
muscles in question for this study it could have skewed the findings of this study.
34
REFERENCES
Behm, D.G., E. E. Bradbury, A. T. Haynes, J. N. Hodder, A. M. Leonard, N. R. Paddock, et al.
2005. Flexibility is not Related to Stretch-Induced Deficits in Force or Power. Journal of
Sports Science and Medicine, 5: 33-42.
Kravitz, L., et al. 2006. Resistance and Flexibility Training: an Ambiguous Relationship
Clarified. IDEA Fitness Journal: 23-25.
35
CHAPTER FIVE
SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS
A. INTRODUCTION
This chapter will give a summary of each chapter of this study. Chapter one deals with
the purpose, need, the null hypothesis, and the statement of the problem. Chapter two contains
summaries the findings of the related studies that were reviewed for this paper. Chapter three
explains how the samples were chosen for this study, the instruments that were used, the
procedures that were followed, and how the data was analyzed. Chapter four presents the results
of this study. This chapter will also present recommendation for future studies concerning this
topic.
B. SUMMARY
CHAPTER ONE
There are four basic parts that physical fitness is composed of: cardiovascular endurance,
flexibility, muscular strength, and muscular endurance. Muscular strength is defined as the
ability of the muscle to generate the maximum amount of force (Sutton 2007). It can also be
defined as the maximum amount of push or pull that can be exerted one time by a muscle group
(Battinelli 2000) and the amount of force that can be generated by the musculature that is
contracting (Morrow 2005). Muscular strength is a commonly used fitness measure for assessing
the strength and power that an individual athlete has (Hoffman 2006).
The definition of flexibility is the ability to move a joint through the full range of motion
without discomfort or pain (Sutton 2007). The lack of flexibility may predispose athletes to
muscle and tendon injuries (Hoffman 2006). There are two types of flexibility, static and
dynamic. The degree of flexibility is specific to each joint and is generally limited by joint
structure, movement dimension capacity, and the elasticity and extensibility of muscle and
connective tissue (Battinelli 2000).
Muscular strength can be measured in two different ways. One way that it can be
measured is through an isometric contraction (Hoffman 2006). The second form of testing is a
dynamic test. The most commonly used type of dynamic test is a one maximum dynamic
contraction test, or a one repetition maximum (1RM) (Golding 2000). Flexibility is expressed in
36
a measure relative to the joint (Gore 2000). Flexibility can be measured using a flexometer and
an inclinometer (Hoffman 2006). It can also be measured using goniometry, visual estimation,
radiography, photography, linear measurements, and trigonometry (Morrow 2005).
The major purpose of this study was to determine a correlation between an individual’s
muscular strength and flexibility. This study was designed to answer of if there was a correlation
between an individual’s muscular strength and flexibility. The null hypothesis for this research
was that there was no correlation between an individual’s muscular strength and flexibility.
Physical fitness is an important aspect of life because it has many health related benefits.
Research has shown that moderate daily physical activity can substantially reduce the risk of
developing or dying from certain diseases such as cardiovascular disease, type II diabetes, and
certain cancers. Daily physical activity can also help decrease blood pressure, lower cholesterol,
reduce obesity, prevent and slow down osteoporosis, and decrease the symptoms of arthritis
(Physical 2008). Since muscular strength and flexibility are both components of physical fitness,
it is important to maximize each one. This study was beneficial to the subjects and the
professional world because it allowed them to see the correlation between muscular strength and
flexibility. By determining the correlation between the two, information can be provided on how
much flexibility is dependant on muscular strength and visa versa.
CHAPTER TWO
The majority of the studies reviewed used a sample consisting of college age students.
Most of the studies included a mixture of male and female participants. Many of the studies used
participants that were not regularly involved in flexibility or strength training activities. The
number of subjects ranged from 16 to 55. One study reviewed used all women, another all men,
and one study used rabbits as subjects.
In the studies reviewed, the instruments that were used to measure range of motion were
the goniometer and a flexometer. Some of the studies used the sit-and-reach test to measure
flexibility. The majority of the tests used some form of knee flexion and extension machine to
calculate the one repetition maximums.
The majority of the studies reviewed were concerned with the effects of pre-event
stretching on the exercise performance. The studies would have the subjects perform certain
forms of stretching before being given a test to determine force, speed, or flexibility.
37
The majority of the studies reviewed used ratios between a control group and the group
that partook in a stretching program. These studies also analyzed ratios between the different
forms of stretching techniques. The paired t test was the most common form of data analysis
used to provide the ratios between the tests.
The majority of the studies reviewed concluded that pre-event stretching caused a deficit
in the exercise performance of the participants. Pre-event stretching caused a decrease in power
output. The studies also concluded that dynamic warm-ups were more beneficial than static
stretching warm-ups and that the addition of flexibility to a strength-training program had no
significant effect on the strength training responses.
CHAPTER THREE
The concern of this study was to determine if there was a correlation between an
individual’s muscular strength and flexibility. The sample the researcher has chosen is
represented by male college aged students who were attending a major metropolitan university.
The data for this study were collected in the fall semester of the 2007-2008 school year. The
subjects for this study were between 18-38 years old. The subjects were chosen randomly by the
students of an exercise testing class.
The instrument used to determine the flexibility of the subjects was a goniometer. The
goniometer is used to measure the angle that is created by the bones of the body at the joints.
The goniometer consists of a moving arm, a stationary arm, and a fulcrum. On the fulcrum is a
scale that ranges from 0 to 180 degrees. The test that was used to determine muscular strength
was the one repetition maximum (1RM) bench press. This test involves the subject lifting the
most weight they can for one repetition.
The testing was done randomly at no certain time of the day. All measurements were
taken with a goniometer in the right shoulder. The movement that was measured was shoulder
abduction. Each measurement was taken twice and the average of the two degrees was taken and
recorded.
The Spearman r was used to analyze the date. The strength and flexibility scores for
given ranks so that they could be compared. This made the date nonparametric. Therefore the
Spearman r was used to determine a correlation between ordinal level data.
38
CHAPTER FOUR
The results of this study show that there is no correlation between muscular strength and
flexibility. The results indicate that the amount of weight that a male between the ages of 18-38
is able to lift during a one repetition bench press has no relation to the shoulder abduction range
of motion. Limitations to this study should be taken into account when stating that this study
accepted the null hypothesis. One limitation was that the testers were not professionals at using
the goniometer. Another limitation to this study was the use of goniometry instead of a more
accurate form of determining range of motion.
C. CONCLUSION
From the results of the findings of this study, the null hypothesis was accepted because
the calculated value of .010 fell within the parameters of the critical value of .250.
D. RECOMMENDATIONS
From the results of this research, the following points are recommended:
1. The researcher should gather all the data. This would increase the internal validity of the
study because the researcher would be doing every test and recording all the data which would
ensure that all the tests were conducted and calculated the same way.
2. Make sure no stretching was done before the 1RM test. The research articles studied showed
that pre-event stretching caused power deficits. If part of the subjects stretched and part of them
did not it would cause data discrepancies.
3. Test a different shoulder movement. The shoulder joint has more than one movement. Each
different shoulder movement should be tested to determine if strength has an affect on any
specific movement.
4. Test the correlation in female subjects. Females should also be tested to increase the external
validity of this experiment.
39
REFERENCES
Battinelli, Thomas. 2000. Pyhsicque, Fitness, and Performance. New York, NY: CRC Press.
Behm, D.G., E. E. Bradbury, A. T. Haynes, J. N. Hodder, A. M. Leonard, N. R. Paddock, et al.
2005. Flexibility is not Related to Stretch-Induced Deficits in Force or Power. Journal of
Sports Science and Medicine, 5: 33-42.
Center for Disease Control and Prevention. 2008. “Components of Physical Fitness.”
http://www.cdc.gov/nccdphp/dnpa/physical/components/.
Cornelius, W., M. Hands. 1992. The Effects of a Warm-up on Acute Hip Joint Flexibility Using
a Modified PNF Stretching Technique. Journal of Athletic Training :112-114.
Golding, Lawrence (ed.). 2000. YMCA Fitness Testing and Assessment Manual. 4th ed.
Gore, Christopher. 2000. Physiological Tests for Elite Athletes. Champaign, IL: Human
Kinetics.
Halvorson, R., et al. 2007. Dynamic Warm-Ups Improve Athletic Performance. IDEA Fitness
Journal: 19.
Hoffman, J. 2006. Norms for Fitness, Performance, and Health. Champaign, IL: Human
Kinetics.
Kokkonen, J., A. G. Nelson, et al. 2001. Acute Ballistic Muscle Stretching Inhibits Maximal
Strength Performance. Research Quarterly for Exercise and Sport, 72(4): 415-419.
Kravitz, L., et al. 2006. Resistance and Flexibility Training: an Ambiguous Relationship
Clarified. IDEA Fitness Journal: 23-25.
Lock Haven University of Pennsylvania. 2001. A Guide to Manual Muscle Testing and
Goniometry.
40
Morrow, J., Jackson, A., Disch, J., Mood, D. 2005. Measurement and Evaluation in Human
Performance. Champaign, IL: Human Kinetics.
Nelson, A., N. Driscoll, D. Landin, M. Young, I. Schexnayder, et al. 2005. Acute Effects of
Passive Muscle Stretching on Sprint Performance. Journal of Sports Sciences, 23(5): 449454.
Nelson, A., J. Allen, A. Cornwell, J. Kokkonen, et al. 2001. Inhibition of Maximal Voluntary
Isometric Torque Production by Acute Stretching is Joint-Angle Specific. Research
Quarterly for Exercise and Sport, 72(1): 68-70.
Nelson, A., J. Kokkonen, C. Eldredge, et al. 2005. Strength Inhibition Following an Acute
Stretch is Not Limited to Novice Stretchers. Research Quarterly for Exercise and Sport,
76(4): 500-506.
The President’s Council on Physical Fitness and Sports. 2000. Definitions: Health, Fitness, and
Physical Activity. http://www.fitness.gov/digest_mar2000htm.
The President’s Council on Physical Fitness and Sports. 2008. “Physical Activity Facts.”
http://www.fitness.gov/resources_factsheet.htm.
Siegel, D. (ed.), et al. 2006. Stretching and Muscular Endurance Performance. JOPERD, 77(5):
5.
Sutton, Amy (ed). 2007. Fitness and Exercise Sourcebook. Detroit, MI: Omnigraphics, Inc.
Tsuang, Y., S. Lam, L. Wu, C. Chiang, L. Chen, P. Chen, J. Sun, C. Wang, et al. 2007.
Isokinetic Eccentric Exercise can Induce Skeletal Muscle Injury within the Physiologic
Excursion of Muscle-Tendon Unit: a Rabbit Model. Journal of Orthopedic Surgery and
Research, 2(13): 1-7.
41
BIBLIOGRAPHY
Battinelli, Thomas. 2000. Physique, Fitness, and Performance. New York, NY: CRC Press.
Behm, D.G., E. E. Bradbury, A. T. Haynes, J. N. Hodder, A. M. Leonard, N. R. Paddock, et al.
2005. Flexibility is not Related to Stretch-Induced Deficits in Force or Power. Journal of
Sports Science and Medicine, 5: 33-42.
Center for Disease Control and Prevention. 2008. “Components of Physical Fitness.”
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APPENDIX A
CONSENT FORM
44
MUSCULAR STRENGTH AND FLEXIBILITY CORRELATION
Invitation to Participate
You are invited to participate in a research study that will determine the correlation between
muscular strength and flexibility in a male college age student. Your participation in this study
is completely voluntary.
Basis for Subject Selection
You are being asked to participate in this study because you are a male student attending a major
metropolitan university. You are also being chosen because you are between the ages of 18-38.
Purpose of the Study
The major purpose of this study was to determine a correlation between an individual’s muscular
strength and flexibility.
Explanation of Procedures
This study will be conducted at the Wellness Center at the University of Tennessee at
Chattanooga. The study will take no longer than thirty minutes to conduct. It is requested that
the subject wear athletic clothing. The study will consist of a bench press one repetition
maximum test and flexibility measurements of the shoulder joint. For the bench press one
repetition maximum test the subject will lift the most weight that they can for one repetition.
The subject will start with a weight close to what is thought to be the most he can lift. The
subject will then increase the weight until the maximum is obtained. For the flexibility test the
subject will move the shoulder through the full range of motion while the tester measures the
movement with a goniometer.
Potential Risks and Discomforts
45
The risk level is low for the one repetition maximum bench press test. Possible risks and
discomforts include dropping the bar on your chest and muscle soreness the following day. The
risk of dropping the bar on your chest is very low because a spotter will be present for this test.
The risk of injury and discomfort from the flexibility testing is very low. The only discomfort
would be from pushing the joint past the full range of motion, which will not be performed for
this test.
Potential Benefits to Subjects
You will benefit by obtaining your one repetition maximum bench press and shoulder flexibility
range of motion.
Potential Benefits to Society
Society would benefit by determining the correlation between a male’s flexibility and muscular
strength, which can help determine the need for flexibility training alongside strength training.
Financial Obligations
The tests will be provided to you free of charge.
In Case of Injury Compensation
In the unlikely event that you should suffer an injury as a direct consequence of the research
procedures describe above, the emergency medical care required to treat the injury will be
provided at the University of Tennessee at Chattanooga at no expense to you, provided that the
cost of such medical care is not reimbursable through your health insurance. However, no
additional compensation for physical care, hospitalization, loss of income, pain, suffering, or any
other compensation will be provided. None of the above shall be construed as a waiver of any
legal rights or redress you might have.
46
Assurance of Confidentiality
Information obtained from you in this study will be treated confidentially. Your name will not be
used in the publishing of the results of this study. Only grouped data will be reported
Rights of Research Subjects
Your rights as a research subject have been explained to you. If you have any additional
questions concerning the rights of research subjects you may contact Institution XYZ Review
Board at 555-555-5555.
Voluntary Participation and Withdrawal
You are free to decide not to participate in this study or to withdraw at any time without
adversely affecting your relationship with the investigators or the University of Tennessee at
Chattanooga. Your decision will not result in loss of benefits to which you are otherwise entitled.
If any information develops or changes occur during the course of this study that may affect your
willingness to continue participating, you will be informed immediately.
Documentation of Informed Consent
YOU ARE VOLUNTARILY MAKING A DECISION WETHER OR NOT TO PARTICIPATE
IN THE RESEARCH STUDY. YOUR SIGNATURE CERTIFIES THAT THE CONTENT
AND MEANING OF THE INFORMATION ON THIS CONSENT FORM HAVE BEEN
FULLY EXPLAINED TO YOU AND THAT YOU HAVE DECIDED TO PARTICIPATE
HAVING READ AND UNDERSTOOD THE INFORMATION PRESENTED. YOUR
SIGNATURE ALSO CERTIFIES THAT YOU HAVE HAD ALL OF YOUR QUESTIONS
ANSWERED TO YOUR SATISFACTION. IF YOU THINK OF ANY ADDITIONAL
QUESTIONS DURING THIS STUDY, PLEASE CONTACT THE INVESTIGATORS. YOU
WILL BE GIVEN A COPY OF THIS CONSENT FORM TO KEEP.
47
_________________________________
Signature of Subject
____________________
Date
MY SIGNATURE AS WITNESS CERTIFIES THAT THE SUBJECT SIGNED THIS
CONSENT FORM IN MY PRESENCE AS HIS OR HER VOLUNTARY ACT AND DEED.
__________________________________
Signature of Witness
____________________
Date
IN MY JUDGEMENT THE SUBJECT IS VOLUNTARILY AND KNOWINGLY GINVING
INFORMED CONSENT AND POSESSES THE LEGAL CAPACITY TO GIVE INFROMED
CONSENT TO PARTICIPATE IN THE LEGAL STUDY.
__________________________________
Signature of Investigator
____________________
Date
Billy Wilson
(423) 413-1234
48
APPENDIX B
DATA COLLECTION FORM
49
STRENGTH AND FLEXIBILITY MEASURES
Date: _____________
Flexibility
B.
1.
SHOULDER COMPLEX
Flexion
ROM 0-180°
2.
Extension
ROM
________ ________
L
R
______ ______
0-60°
L
3.
Abduction
ROM
0-180°
______ ______
L
4.
Medial Rotation
ROM
0-70°
External Rotation ROM
0-90°
Machine
Name
1RM
R
______ ______
L
Exercise
R
______ ______
L
5.
R
60%
70%
R
80%
Bench
press
50