Effect of dynamic versus static stretching in the
warm-up on hamstring flexibility
ISSN: 1543-9518
Gayle
Silveira, Mark Sayers, Gordon Waddington - Department of Health, Design and
Science, University of Canberra
Abstract
Recent
studies have questioned the benefits of static stretching in the sports
warm-up. The purpose of our research was to examine the acute effect of static
and dynamic stretching in the warm-up, on hamstring flexibility using an
intervention study design. Hamstring flexibility was measured using
modifications of the Straight Leg Raise test to measure hip flexion range of
motion in degrees. The reliability of the test setup was determined in a
separate study (n=33), the results of which were also utilised to establish the
relationship between static and dynamic SLR tests. There was a significant
difference between flexibility measured by the Static-passive and the
Dynamic-supine SLR test (p < .05); hence, these were utilised to assess
static and dynamic flexibility, respectively, in the intervention study.
Twelve
participants were randomly assigned to three interventions of 225 secs. stretch
treatment on separate days: No stretching (Treatment 1), Static stretching
(Treatment 2) and Dynamic stretching (Treatment 3) in a cross-over study design.
When static stretching was included in the warm-up, there were statistically
significant differences in pre and post static flexibility (t (11) = 4.19, p
< .05). However, there was no significant difference in pre and post dynamic
flexibility (t (11) = 0.72, p >.05). Following dynamic stretching there was
a statistically significant improvement in both static (t (11) = 2.62, p <.
05) and dynamic (t (11) = 5.69, p < .05) flexibility. Non-parametric tests
carried out on the data to corroborate the aforementioned findings.
Static
stretching did not improve dynamic hamstring flexibility; however, dynamic
stretching improved both dynamic and static flexibility. This has implications
for the specificity of stretching in sport.
Abbreviations
ROM
range of motion
SPH
static passive hamstring flexibility
test
DSUH
dynamic supine hamstring flexibility
test
DSHWB
dynamic standing hamstring
flexibility test with knee brace
DSHNB
dynamic standing hamstring
flexibility test without knee brace (no brace)
SAID
Specific adaptation to imposed
demands
Introduction
Dynamic
stretching consists of simulating movements that are representative of those
frequently used in a particular sport (22). Examples of dynamic stretching
include the toe walk, heel-walk, hand-toe hamstring stretch, military-walk,
sumo groin stretch, and quadriceps kicks (31). In 1996, Alter (2) described a
principle put forward by Wallis and Logan in 1964 for strength, endurance and
flexibility training, called specific adaptation to imposed demands (SAID). “One
should stretch at not less than 75 percent of maximum velocity through the
exact plane of motion, through the exact range of motion, and at the precise
joint angles used while performing skills in a specific activity” (2). The
aforementioned principle lends support to the concept of dynamic flexibility
training. There is a lack of studies that examine the effect of dynamic
stretching on static as well as dynamic flexibility in the period preceding
competition i.e. in the warm-up phase.
Numerous
studies in recent literature examine the effects of static stretching on
various performance variables (29, 37). In their 2006 study, Behm et al. (6)
found decrements in knee extension, knee flexion, drop-jump contact time and
counter movement jump height following an acute bout of static stretching. The
analysis of the relationship between static stretching and performance focuses
mainly on the variables of strength and power (30). Their study demonstrates
that static stretching lowers the maximal strength of the knee flexors and
extensors and may even hamper performance of activities involving maximal force
output. If increased musculotendinous stiffness enables more efficient
transmission of force, stretching just prior to activity might also decrease
force output in skills such as jumping to attain maximum height and forceful
throwing (12). Even a moderate duration of static stretching could result in
quadriceps isometric force and activation decrements (33). Furthermore, it is
theorised that this impairment of isometric force production could last for a
period of up to 120 minutes.
The purpose
of our research was to examine the acute effect of static and dynamic
stretching in the warm-up, on hamstring flexibility using an intervention study
design. The reliability of the experimental setup was established in a separate
study (n=33) that was used to determine the relationship between the tests that
measured static and dynamic hamstring flexibility. Analyses of variance and
correlation analyses were computed on the collated data. An intervention design
was used to determine how an acute bout of static or dynamic stretching
affected hamstring flexibility as measured by a modified SLR test. Parametric
(t-test) and non-parametric tests (Wilcoxon Matched-Pairs Ranks) were carried
out to analyse the raw data.
Method
Participants
Sixteen
university students (n = 16) were recruited for the intervention study to
examine the effects of dynamic and static stretching on hamstring flexibility.
The final sample consisted of 12 students of which five females and seven males
served as participants. Two potential participants did not complete all testing
sessions and two participants’ data was excluded from the study due to
measurement error. The average age of the participants was 24.8 ± 6.8 yrs.
(mean ± SD). The average height and weight was 174.5 ± 4.5 cm. and 73.0 ± 15.7
kg. respectively (mean ± SD).
Participants
were drawn from a variety of sporting backgrounds which predominantly involved
the lower body
(42). Most were actively training for a sport. All trained
lightly a minimum of three times a week. A condition of entry to the study was
that the subjects did not concurrently use any stretch or flexibility training
in their regular training program (
41). Screening questionnaires were provided to identify
subjects with neurological or musculoskeletal abnormalities of the spine and
lower limbs. Subjects were examined to determine hip, knee and ankle ROM and a
brief examination of the lumbar spine was performed. The final participants
were free of any bony or soft tissue injury to the spine and lower limbs. The
participants were asked to carry out routine activities and not to exercise
strenuously
(10). They were also advised not to stretch the hamstrings and
avoid initiating or changing any exercise program during the study
(35).
All
participants provided their written informed consent to participate in the
study. Hamstring flexibility was measured in the dominant leg
(19), identified by kicking a football towards a wall five
times
(11). This study received approval from the human ethics
committee of the University of Canberra.
Materials and Procedure
Reflective
markers attached to specific bony prominences utilised for biomechanical
analysis (Figure 1). The functional orthopaedic knee brace, Knee Ranger II
Universal (dj Orthopaedics, LLC, California, USA) helped to maintain 15º of
knee flexion during pre and post-testing. Participants wore the knee brace only
during testing and not whilst performing the intervention stretches. The Velcro
strapping on the brace eased the removal and fastening process considerably. A
warm-up consisting of five minutes of cycling on a stationary cycle ergometer
(Exertech, Australia) at 60-70 W
(6, 42) was employed. Testing was carried out at around the
same time of the day for each participant involved in the intervention study
(41). There was no stretching incorporated in the warm-up.
Modified SLR test for measuring hamstring flexibility
Previous
studies examining stretch and contraction specific changes in ROM utilise the
hamstring muscle group most frequently in humans and the SLR test is the most
commonly used test
(17). The contralateral or non-testing leg was partially
flexed at the hip and knee, with a pillow rolled underneath the knee to
stabilise the pelvis
(11). A Velcro strap fastened around the pelvis and secured
beneath the exercise bench to minimise pelvic rotation. In 1982, Bohannon (7)
suggested that the pelvis and the contralateral thigh should be maintained in
neutral position to decrease contribution to SLR-ROM. During testing, the
participant was advised not to lift the upper body off the bench, and the arms
were folded across the chest or placed beneath the head. This minimised the
contribution from the trunk towards the effort of hip flexion.
The
experimental setup included a camcorder placed perpendicular to the plane of
motion. The camcorder was mounted on a tripod and placed at a distance of 10
metres from the test area (Figure 1). A PAL digital video camera (Canon MVX3i,
Canon Inc., Japan) operating at 50Hz was used to video the participants
performing the various flexibility tests. Dartfish ProSuite (Dartfish Connect
4.0, Dartfish Ltd., Fribourg, Switzerland) was used to capture the video data
from the camera to a computer for two-dimensional analysis.
Measuring Flexibility
After the
warm-up period, participants (n=12) undertook static passive (SPH) and dynamic
supine hamstring flexibility (DSUH) tests to measure static and dynamic
flexibility respectively. The reliability of this experimental setup and
correlation between modifications of the SLR test was established in an earlier
study involving 33 subjects.
Static Passive Hamstring Flexibility test
This test
was performed in the supine position on an exercise bench. The functional knee
brace was worn for testing. Passive stretching utilises an external agent to
assist with the stretch. The participant used a Velcro strap around the ankle
to assist with pulling the limb into hip flexion (Figure 1). The dominant leg
was flexed to the terminal ROM or until a mild discomfort/tightness was felt in
the back of thigh
(5). This position was maintained for five seconds following
which the limb was slowly lowered to the resting position.
Dynamic Supine Hamstring Flexibility test
The test was
performed in the supine position on an exercise bench. Dynamic flexibility
measures the ability to move a joint quickly through a non-restricted ROM. The
participants were instructed to move the dominant limb into hip flexion using
maximal effort and as quickly as possible or until a mild discomfort was felt
in the back of the thigh. Dartfish analysis of the video frame that captured
the terminal phase of movement was used to determine the angle of hip flexion.
Supine
stretching is thought to better isolate the hamstrings, allowing for improved
relaxation and is generally believed to be safer and more comfortable for
people with a history of low back pain (15). Hence, the SPH test was used to measure
static hamstring flexibility and the DSUH test was used to measure dynamic
flexibility. Reliability testing demonstrated that there is a significant
difference between flexibility measured by the SPH and DSUH hamstring
flexibility tests (p<.001). There was also a significant difference between
DSHWB (with knee brace) and DSHNB (without knee brace) tests (p = .003) and
this result supported the use of the knee brace (dj Orthopaedics, LLC,
California, USA) to maintain a fixed knee angle during flexibility testing.
An average
hip flexion ROM was calculated for both and served as the final measure of
hamstring flexibility
(4). Post-testing was commenced immediately after the
completion of the stretching intervention assigned for the day. In 2002, Klee
et al. (26) suggested that participants should be retested as quickly as
possible after the intervention stretches because resting tension started to
increase after a three minute rest pause.
Stretching Program
Warm-up only/ No stretching: Treatment 1
No stretches
were included in the warm-up, serving as a control. Participants cycled for 75
seconds on a stationary ergometer (Exertech, Australia) at 60-70 W with a 10
seconds rest pause between each of the five 75-second cycle periods. Total
duration of cycling was 225 secs.
Static stretching: Treatment 2
Participants
performed stretches for a total duration of 225 seconds (52). They performed
three types of static stretches with a stretch time of 75 seconds for each
(Table 1). This time equated to five stretches held for 15 seconds each (9, 29,
30, 34, 47,). A rest pause of ten seconds was allowed between stretches. Each
static stretch was performed to the terminal range, defined as the point where
the subject felt a mild discomfort or tightness in the back of the thigh (5).
The static and dynamic stretching routines were appropriately timed so that the
amount of time spent stretching was the same for each group, enabling
comparison between the two groups
(41).
Standing toe-touch
This stretch
routine involved bending forward to touch toes whilst making sure that the
knees remained fully extended. Participants held the stretched position for 15
seconds until a slight sense of discomfort or tightness felt in the back of the
thigh. Ten seconds rest pauses were allowed after each stretch and when
switching to a different stretch type.
Forward swing static stretch
The heel of
the extremity to be stretched was supported on a treatment table to perform
this particular stretch
(35). The knee remained fully extended and the foot was
positioned in relaxed plantar flexion. The pelvis was tilted anteriorly whilst
bending forward at the waist avoiding flexion of the spine
(15, 35), until the terminal range was reached or discomfort
felt in the back of the thigh. This stretch position was held for 15 seconds
and repeated five times on the dominant extremity.
Passive supine-sling stretch
This stretch
was performed in the supine position whilst lying on an exercise treatment
bench. A Velcro sling was passed around the ankle to flex the hip and
consequently stretch the hamstring group of muscle. The stretch was held for 15
seconds to the terminal range of discomfort or tightness felt in the back of
the thigh.
Dynamic stretching treatment
Five sets of
seven to eight dynamic stretches equalled the amount of time spent (Table 1) on
the aforementioned static stretching regimens. The aim was to allot the same
amount of stretching time to the static and dynamic stretching interventions
enabling comparison among the groups. The 15 seconds hold period for each
static stretch equated to around seven to eight dynamic stretches. Five sets of
dynamic stretches amounted to 225 seconds of total stretching time. There was a
pause of 10 seconds between each set and another 10 seconds when changing over
from one type of stretch to another.
Stretches
were begun at low velocity and momentum was gradually built up to achieve at
least 75% of maximum height and speed while performing the dynamic stretches.
The SAID principle of specific adaptation to imposed demands formed the basis
of the dynamic stretching routine. Participants stretched at 75% of the maximum
velocity through a particular ROM whilst performing a sport-specific movement.
Dynamic leg swings
The dominant
leg was flexed at the hip in a forward kicking action. The aforementioned SAID
principle was applied during performance of all stretches (controlled
stretching). Five sets of seven or eight forward leg swings or kicks
(9)were carried out to a timed 225 seconds of stretching.
Crossed-body leg swings
Dominant leg
swung across the midline of the body towards the opposite shoulder. This
stretched the biceps femoris which is the lateral muscle of the hamstring group
(40).
Standing bicycle-kicks
The dominant
limb was put through a circumduction-like movement in a rhythmic cyclical
manner incorporating the SAID principle (controlled stretching). Total time
spent on this stretch was also 225 seconds.
Biomechanical analyses
The hip ROM
in the dominant leg was used as an indirect measure of hamstring flexibility
(44)and served as the only investigated parameter (Fully
extended hip = 0°). Dartfish ProSuite (Dartfish Connect 4.0, Dartfish Ltd.,
Fribourg, Switzerland) is a complete video analysis software package, which
includes all necessary functionality to analyse technical performance during
and after training. Dartfish motion analysis software was used to quantify the
degree of hip flexion. This system enables access to every video frame so that
the terminal ROM of hip flexion can be accurately identified. Once the
appropriate frame was identified, Dartfish was used to measure hip flexion
accurately to the nearest degree. Intra-tester and operator reliability were
tested by a repeat analysis of 15 participant performances.
Statistical Analysis
The
principal dependent variable of interest was the change in hamstring
flexibility measured by hip flexion ROM between pre and post-stretch
measurements. The paired sample t-test compared the effect of the two
treatments on static and dynamic hamstring flexibility. Non- parametric tests
conducted on the collected data corroborate the aforementioned findings.
Furthermore, Tukey’s Honestly Significant Difference (HSD) test explored the
degree of change in static and dynamic flexibility. The data was analysed with
the statistical package SPSS for Windows (version 12.1.0; SPSS Inc., Chicago,
IL).
Results & Disscussion
Various
modifications of the SLR test were used to measure and compare hamstring
flexibility in an earlier study that also tested for reliability (n=33). Static
passive hamstring flexibility (SPH), dynamic supine hamstring flexibility
(DSUH), dynamic standing hamstring flexibility with knee brace worn (DSHWB),
and dynamic standing hamstring flexibility without knee brace (DSHNB). Subjects
were tested on two separate occasions one week apart. Each subject had three
trials for each tests for the two separate testing times resulting in a total
of 30 scores. Test-retest was appropriate as subjects were tested at two points
in time a week apart and a Cronbach alpha was used to test for internal
consistency and reliability for the three trials of each week’s testing. The
tests used in this study evidenced a very high degree of internal consistency
for each trial by Occasion 1 and Occasion 2 as well as a high coefficient of
reliability or stability as measured by the test-retest procedure (Table 3,
Table 4).
Participants
were randomly assigned to one of three interventions for each of three testing
occasions:
- No
stretching (Treatment 1)
- Static
stretching (Treatment 2)
- Dynamic
stretching (Treatment 3)
A
Paired-samples T-test was used to test for differences in static and dynamic
flexibility from pre/post-test after each stretch intervention (Table 5).
Intervention
Treatment 1, where the subjects did no stretching served as the control. Static
and dynamic stretching (Treatment 2, Treatment 3) were the experimental treatments.
Following Treatment 1 we expected measures of hamstring flexibility to remain
unchanged from pre to post-test. However, our analysis revealed significant
differences between pre and post score for static flexibility (t (11) = 2.76, p
< .05). There was no significant difference between pre and post hip ROM
measured by the dynamic flexibility test (t (11) = 0.315, p >.05). The mean
value of difference between pre and post score for static flexibility (mean =
2.13, SD = 2.68) indicates that there is a substantial change.
When static
stretching was included in the warm-up, there were statistically significant
differences in pre and post static flexibility measurements (t (11) = 4.19, p
< .05). However, there was no significant difference in pre and post dynamic
flexibility measurements (t (11) = 0.72, p >.05). When dynamic stretches
were included in the warm-up instead of static stretches, it was expected that
there would be changes, at least, in dynamic flexibility of the hamstrings. The
analysis shows that there were statistically significant differences in both
static (t (11) = 2.62, p <. 05) and dynamic (t (11) = 5.69, p < .05)
flexibility. This suggests that participants improved both their static and
dynamic hamstring flexibility after dynamic stretching was included in the
warm-up.
Non-parametric
tests were carried out on the collected data to corroborate the aforementioned
findings. Wilcoxon Matched-Pairs Ranks test was performed. The results were
similar to those obtained following the Paired samples t-test. Following
Treatment 1 (No stretching) there were resultant differences in the static
hamstring flexibility (Wilcoxon, Z = -2.41, p < .05). Static stretching only
influenced static flexibility (Wilcoxon, Z = -2.67, p < .05) of the hamstrings,
while dynamic stretching produced changes in both static (Wilcoxon, Z = -2.39,
p < .05) and dynamic flexibility (Wilcoxon, Z = -2.98, p < .05).
Furthermore,
the differences in the degree of change in static and dynamic flexibility
following dynamic stretching were explored using Tukey’s Honestly Significant
Difference (HSD) test. The difference between the degree of improvement in
static and dynamic hamstring flexibility following dynamic stretching were not
statistically significant (Table 6). To corroborate these findings a Wilcoxon
Matched-Pairs Ranks test was performed on pre-post differences of static and
dynamic flexibility following dynamic stretching. The analysis failed to
identify a significant difference in the changes demonstrated in both static and
dynamic flexibility (Wilcoxon, Z = -0.178, p > .05).
The
availability of state of the art software and improved video analysis
techniques has changed the way flexibility is measured. The methods commonly
being used have focussed on the measurement of static flexibility. With the
growing trend towards using dynamic stretching and sport-specific drills in the
warm-up, there is a need for measuring devices to adapt to these changes. We
have provided a simple, reliable setup to measure flexibility. The inadequately
defined relationship between flexibility and muscular performance or an
athlete’s susceptibility to injury may be attributable to the lack of valid and
reliable measures of flexibility (20). The drawback of flexibility assessment
tools is the need for testing to be carried out within the confines of a
laboratory. Although this study was carried out in a laboratory, the set-up
could be used outdoors with the participant performing functional dynamic
sporting movements.
Dynamic
flexibility has been defined as a measure of the resistance throughout the ROM
of a joint or a measure of joint stiffness
(3). Dynamic flexibility is important in sport because it
measures the ability of an extremity to move through a non-restricted ROM
(36). The main findings suggest that static stretching
improves static flexibility (p < .05) but may have no impact on dynamic
flexibility (p > .05). Increasing ROM achieved through static stretching
does not necessarily translate to improvements in dynamic flexibility. In 2004,
Behm et al.
(6)supported the concept that static stretching improved
flexibility and ROM, however, it was believed that the relevance and
specificity of the gains remained questionable.
In 1988,
Alter (1) argued in support of the specificity of stretching: “ROM is a
combination of active and passive ranges of motion and if passive stretching
exercises are used to develop flexibility, then one should expect changes
largely in passive flexibility” (p.179). Even a moderate duration of static
stretching could result in quadriceps isometric force and activation decrements
lasting for up to 120 minutes (33). The increase in static flexibility may not
have translated into expected improvements in dynamic flexibility because of
dampened hamstring activation following an acute bout of static stretching.
Static
flexibility improved when no stretches were included in the warm-up as well as
when the participants underwent a static stretching routine. Similar results
were obtained in a other studies
(44, 53). The 2003 study by Zakas et al. (53) indicates that
flexibility improves significantly even when stretching is not included in the
warm-up, however, any comparisons should be made with caution because of
differences in methodology. The stationary cycling group in the study in 1997
by Wiemann and Knut (44) cycled for 15 minutes and demonstrated a significant
improvement in hip ROM thereafter. They explain that this occurrence may be due
to the decreased resting tension and a reduced stretch resistance following
stationary cycling. However, other studies have shown that warming up before
stretching does not complement the effectiveness of stretching (14, 45).
Following
the inclusion of dynamic stretches in the warm-up, dynamic flexibility as well
as static flexibility scores improved from pre-test to post-test. However,
Tukey’s HSD test did not reveal significant differences between the degree of
improvement of static and dynamic flexibility. Muscles have two types of
receptors: the primary or annulospiral endings which measure changes in both
muscle length and velocity, and the secondary or flower spray endings that
measured changes in muscle length alone
(2). Thus, Alter (2) reasons that dynamic stretching may be
used to condition primary endings for a desired response, and sport-specific
drills could be used in warm-up. Dynamic stretching may have caused activation
of the primary annulospiral endings resulting in an increase in both static and
dynamic flexibility. The dynamic stretching routine may have had a warming up effect,
causing an increase in static flexibility.
There may be
a need to consider the appropriate time for static stretching in the daily
training schedule. There have been suggestions that static stretching may be
useful in the cooling down period after a workout (18, 27, 31-32). Evidence
remains in support of static stretching for long-term gains in flexibility (31,
39).
Conclusion
The
intervention study comparing the effects of static and dynamic stretching
routines in the warm-up on hamstring flexibility demonstrated that dynamic
stretching enhanced static as well as dynamic flexibility. Static stretching on
the other hand did not have an impact on dynamic flexibility. This has
implications for the use of static stretching in the warm-up for dynamic sport.
The role of static stretching for injury prevention in dynamic sport is also
being questioned.
Application in Sport
The
simplicity of the experimental set-up is the highlight of this research.
Coaches can use our method of video analysis to monitor the effectiveness of
stretching routines. A single person can carry out testing with ease and
accuracy.
Dynamic
stretching is synonymous with functional, sport-specific stretching and this
research has demonstrated that dynamic stretching improves both static and
dynamic hamstring flexibility. Static stretching has no impact on dynamic
flexibility and should not be used in the warm-up; however, static stretches
may be useful in the cooling down period of training for long term gains in
flexibility.
Although our
research has demonstrated the effectiveness of dynamic stretching in the
warm-up, it is important to follow the training guidelines set aside in 2001 by
Mann and Whedon
(31)whilst implementing a stretching routine. Dynamic
stretching may be most effective if performed according to the training
principles discussed earlier, always making sure the needs and the capacities
of the individual athlete receive precedence over general training goals.
Acknowledgements
I would like
to acknowledge my supervisors Dr. Mark Sayers and Dr. Gordon Waddington for
their invaluable guidance. Their understanding and patience helped me overcome
numerous hurdles en route to the completion of this thesis. I would also like
to thank the sports studies staff for their help and advice.
I am
thankful to the students of the University of Canberra (Sports Studies) for
volunteering to participate in this research project. It was wonderful working
with such cheerful and enthusiastic young people. Their willingness to participate
and report at similar times for each testing session is much appreciated.
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Tables
Table 1
Time spent
on each stretch
|
Stretch Type
|
Stretch Time (seconds)
|
|
Static
stretching*
|
|
|
Toe-toucha
|
75c
|
|
Forward
swinga
|
75c
|
|
Surpine
slinga
|
75c
|
|
Dynamic
stretching*
|
|
|
Forward
leg swingb
|
75d
|
|
Crossed-body
leg swingb
|
75d
|
|
Bicycle
kicksb
|
75d
|
(*) 10
seconds rest pause after each repetition and 10 seconds before switching over
to the next type of stretch.
(a) 5 Stretches
(b) 5 Sets
(c) 15 seconds hold for each static stretch
(d) 7-8 swings/ kicks equivalent to around 15 seconds of stretching time for
each set.
Table 2
Comparison
of Dynamic and Static Hamstring flexibility measures in reliability study
|
Test 1b
|
Test 2a
|
Test 1
Mean (SD)
|
Test 2
Mean (SD)
|
F
|
df
|
P
|
Part Eta2
|
|
SPH
|
DSUH
|
91.90
(18.02)
|
88.61
(16.97)
|
18.20
|
1.000
|
< .001
|
.363
|
|
SPH
|
DSHNB
|
91.90
(18.02)
|
89.96
(15.91)
|
1.28
|
1.000
|
.267
|
.038
|
|
DSUH
|
DSHWB
|
88.61
(16.97)
|
91.66
(15.65)
|
4.46
|
1.000
|
.043
|
.122
|
|
DSUH
|
DSHNB
|
88.61
(16.97)
|
89.96
(15.91)
|
.835
|
1.000
|
.368
|
.025
|
|
DSHWB
|
DSHNB
|
91.66
(15.65)
|
89.96
(15.91)
|
10.44
|
1.000
|
.003
|
.246
|
Significant
at p < .05
(a) All measurements are in degrees
(b) Number of participants performing each test = 33
Table 3
Cronbach
alpha measure of reliability for each test repetition for two test sessions
|
Flexibility Test
|
Alpha Occasion
(SEM)*
|
Alpha Occasion 2
(SEM)*
|
|
Static-passive
hamstring
|
.9950
(1.28)
|
.9946
(1.32)
|
|
Dynamic-supine
hamstring
|
.9908
(1.71)
|
.9891
(1.77)
|
|
Dynamic-standing
hamstring with brace
|
.9915
(1.45)
|
.9917
(1.42)
|
|
Dynamic-standing
hamstring no brace
|
.9905
(1.51)
|
.9897
(1.61)
|
(*) SEM -
Standard Error of Measurement.
Table 4
Test -
retest reliability
|
Flexibility Test
|
Coefficient of Stability / Reliability (SEM)
|
|
Static-passive
hamstring
|
.992
(1.61)
|
|
Dynamic-supine
hamstring
|
.993
(1.45)
|
|
Dynamic-standing
hamstring with brace
|
.989 (1.66)
|
|
Dynamic-standing
hamstring no brace
|
.983
(2.04)
|
Table 5
Paired
samples T test comparing the effect of the intervention treatments on dynamic
and static hamstring flexibility
|
Treatmentb
|
Pairs (Pre-Post Test Scores)
|
Mean (SD)
|
Std. Error Mean
|
95% Conf. Int. of the Difference
|
ta
|
Sig. (2-tailed)
|
|
Lower
|
Upper
|
|
No stretch
|
Static
flexibility
|
2.13
(2.68)
|
0.77
|
0.43
|
3.84
|
2.758*
|
0.019
|
|
Dynamic
flexibility
|
0.23
(2.57)
|
0.74
|
-1.40
|
1.87
|
0.315
|
0.759
|
|
Static
stretching
|
Static
flexibility
|
4.04
(3.34)
|
0.96
|
1.92
|
6.16
|
4.191*
|
0.002
|
|
Dynamic
flexibility
|
1.35
(6.51)
|
1.88
|
-2.78
|
5.48
|
0.719
|
0.487
|
|
Dynamic
stretching
|
Static
flexibility
|
1.86
(2.46)
|
0.71
|
0.30
|
3.42
|
2.622*
|
0.024
|
|
Dynamic
flexibility
|
1.75
(1.06)
|
0.31
|
1.07
|
2.43
|
5.694*
|
0.000
|
(*)
Significant at p < .05
(a) Degrees of freedom = 11
(b) Number of participants undergoing each treatment = 12
Table 6
Tukey’s
Honestly Significant Difference (HSD) test exploring differences in the degree
of change in static and dynamic flexibility following dynamic stretching
|
Experimental Group
|
Dependent Variable (I)
|
Intervention (J)
|
Mean Difference (I-J)
|
Std. Error
|
Sig.
|
|
Dynamic
Stretching
|
Post
Static Flexibility
|
No
Stretching
|
-0.006
|
4.14
|
1.00
|
|
|
Static
stretching
|
1.08
|
4.14
|
0.96
|
|
Post
Dynamic flexibility
|
No
stretching
|
-1.24
|
4.60
|
0.97
|
|
|
Static
stretching
|
-1.13
|
4.60
|
0.97
|
