Stretching Techniques to Improve Flexibility in
Special Olympics Athletes
and Their Coaches
Christine Stopka, Kevin Morley, Ronald Siders,
Josh Schuette, Ashley Houck, and Yul Gilmet
Objective/Context: To examine the effects of static and proprioceptive neuromuscular
facilitation (PNF) stretching in Special Olympics athletes and their coaches on sit-andreach performance. Design/Participants: Repeated-measures ANOVA with Scheffé
post hoc analyses on 2 groups: Special Olympics athletes (n = 18, mean age = 15.7)
and their coaches without mental retardation (n = 44, mean age = 22.2). Intervention/
Outcome Measures: Stretching performance was measured in centimeters using a sitand-reach flexibility box, examining 2 series of 3 stretches. For both groups, the first
set of 3 stretches was performed in the following order: baseline, static, PNF. Three to
4 weeks later, the order of the stretches was reversed: baseline, PNF, static. Results:
PNF stretching improved performance regardless of stretching order after baseline and
static measures. Static stretching improved performance only from baseline. Conclusions: Individuals of various ages and cognitive abilities can apparently perform and
benefit from PNF stretching. Key Words: PNF techniques, special populations, mental
retardation, flexibility training
Stopka C, Morley K, Siders R, Schuette J, Houck A, Gilmet Y. Stretching techniques to improve flexibility
in Special Olympics athletes and their coaches. J Sport Rehabil. 2002;11:22-34. © 2002 Human Kinetics
Publishers, Inc.
Although much attention has been given to investigating the benefits of,
need for, and protocols addressing improvements in flexibility in fitness
programs for the general public,1-10 studies examining physical fitness and
flexibility in populations with disabilities, especially those with mental
retardation (MR), have been largely neglected. Recently, researchers have
examined other aspects of physical fitness, such as muscular strength and
endurance, work capacity, and cardiorespiratory endurance, in individuals
with MR.11-24 Although some researchers have discussed flexibility in this
population,18,25-33 fitness studies with a major focus on flexibility are rare.34
The authors are with the Dept of Exercise and Sport Sciences at the University of
Florida, Gainesville, FL 32611.
22
Static/PNF Techniques on Special Olympians and Coaches
23
Flexibility, according to Alter,35,36 is the ability to move a joint or joints
through the normal range of motion without stress to the musculotendinous
unit. Flexibility plays an integral role in joint mobility, athletic performance,
and injury prevention.8,37-41 In both fitness and physical education settings,
the term flexibility refers to functional stretching ability while performing
activities of daily living, recreation, and sport without injury.42-44
Regular sessions of stretching to increase flexibility have become a
strategy employed by athletic trainers, physical therapists, and fitness
advocates alike. Gains in flexibility occur when a constant force is applied
and progressive changes in length occur.2,4,6,9,34,35,43,45-47 Static and proprioceptive neuromuscular facilitation (PNF) stretching are 2 of the most common
techniques used for improving flexibility.6,43,44,47-49
By definition, static stretching requires individuals to sustain a stretch
at their maximum range of motion for a designated amount of time.45,50
Through continuity and proper technique, increased flexibility has been
demonstrated. PNF, in contrast, focuses on relaxing the muscle to be
stretched. The form of PNF employed in this investigation is known as
the hold-relax technique, which involves a sustained isometric contraction
(6–10 seconds) of the muscle being stretched.34,43,44,46 An isometric contraction is defined as one in which the muscle develops tension but does not
shorten.41-43,50 To achieve maximal stretch, the muscle is passively stretched,
held in a sustained isometric contraction, and then relaxed; then the muscle
is passively stretched again.9,44,46,51 A modified version uses a towel instead
of a partner or therapist for the isometric contraction.34,35,44,46,52 The resulting
gains in stretching ability are caused by autogenic inhibition; the contraction
of the antagonist muscle causes relaxation of the agonist, resulting in an
increase in stretching ability.2,43,44,46
Considering the documented effectiveness of the aforementioned stretching techniques in the general population, the purpose of the current investigation was to examine static and PNF hold-relax stretching in individuals
with MR (Special Olympians) and those without MR (their coaches). The
focus was to determine whether there were significant differences between
the stretching techniques performed within each series (baseline, static, PNF
or baseline, PNF, static). The series format was used to allow each person’s
stretch to serve as a control, or reference point, for the subsequent stretch.
Thus, the objective was to observe the amount of change between the techniques, if any, rather than the absolute score of the stretch. Also, we wanted
to determine whether it is possible to teach individuals with MR the static
or hold-relax PNF stretching technique in a concise and comprehensible
manner. Therefore, the hypothesis, stated in the null, is that there would
be no difference in sit-and-reach performance between the 2 stretching
techniques, regardless of order or the presence of MR.
24
Stopka et al
Methods
Participants
The group with MR consisted of 18 Special Olympics athletes (age 15–22
years, mean = 15.7; 12 male, 6 female) with mild to moderate MR from the
Sidney Lanier Center in Gainesville, Fla. Participants were classified as having mild to moderate MR based on their scores on intelligence and adaptivebehavior tests.21,22,52 (For example, using the Stanford-Binet Scale, an IQ of
52–67 is classified as mild MR, and 36–51 as moderate MR.21) The physical
education program for these student athletes was held at the University of
Florida as part of their individual transition plans, which encouraged the
learning of lifetime/Special Olympics sports and integration with nondisabled peers. None of the participants had Down’s syndrome or any other
physical or medical condition affecting joint mobility. The combined-gender format permitted comparison to true-to-life teaching situations, which
nearly always consist of both male and female students in a classroom
setting.53 Each student, with his or her parent or guardian, completed an
informed-consent form/assent script approved by the university institutional review board, as well as a Special Olympics medical-release form.
Forty-four participants without MR (age 19–50 years, mean = 22.2; 15 men,
29 women) from the university signed an informed-consent form approved
by the institutional review board to permit collection of normative data.
These participants, although slightly older in mean age than the MR group,
enabled comparison with a typical active adult-age population and were
recruited from classes at the university. Most of them participated in the
aforementioned lifetime sports program as the Special Olympics athletes’
coaches and practice teammates.
Test Apparatus
For both groups, measurements, in centimeters, were taken with the same
equipment and by the same investigators throughout the study to ensure
accuracy and identical instructions. All data were collected at the Living Well
Center at the University of Florida, using a sit-and-reach box and observing
validated protocols.1,5,7,54-59 The box was constructed from a plastic crate and
a meter stick, because the commercially available flexibility boxes could not
accommodate the larger foot sizes of the youths and young adults tested.
Procedure
After a brief aerobic warm-up, a baseline score was determined by measuring the stretching performance achieved in the sit-and-reach position
(with knees extended throughout all the tests).5,34,60 Then, each participant
performed a 10-second static stretch, followed by a 10-second relaxation,
and their stretching performance was measured and recorded. Next, a 10-
Static/PNF Techniques on Special Olympians and Coaches
25
second PNF stretch was performed, followed by a 10-second relaxation, and
their stretching performance was measured and recorded. Only 1 attempt
of each technique was permitted in order to negate any extraneous effects
of practice. The 10-second stretching duration was chosen in an attempt to
mimic “real world” scenarios, wherein the average person rarely performs a
stretch for the recommended 15–30 seconds.51,53 To address internal-validity
concerns (test-construction bias), the procedure was repeated with the order
of the stretches reversed (PNF first, then static) for both groups approximately 3–4 weeks later, with no intervention between testing sessions.
To perform the PNF stretch, a towel was placed around the soles of the
feet and participants were instructed to grasp the towel as close to their
feet as was comfortable. Participants were then asked to plantar flex their
ankles against the towel and lean back for 10 seconds, while maintaining
the same hand placement on the towel, and to “sit up as tall as you can and
keep your back straight so you can feel the stretch in the back of your legs
while you pull back on the towel.” The “sit up tall” request helped isolate
the calves, hamstrings, and back muscles—the target muscle groups for
the isometric contraction—while de-emphasizing the arms and shoulders
(which would have been targeted more if the person was slouching). After
10 seconds, the participants were instructed to cease the contraction and
reach forward toward their toes to establish a terminal measurement (see
Figures 1–3).
Analysis
A repeated-measures analysis of variance (ANOVA) was conducted for each
Figure 1
Baseline test.
26
Stopka et al
Figure 2
PNF stretching technique.
Figure 3
Posttreatment test.
of the 2 test groups, the Special Olympians and their coaches without MR.
Scheffé post hoc analyses were used to identify any significant differences
between the baseline and static stretches, the baseline and PNF stretches,
and the static and PNF stretches. The .05 level of significance was used
for all statistical comparisons. The data were analyzed using the SPSS/PC
software program.61
Static/PNF Techniques on Special Olympians and Coaches
27
Results
The results of this investigation revealed that Special Olympics athletes
with mild to moderate MR and their coaches without MR demonstrated
improvements in sit-and-reach performance after applying static and PNF
stretching techniques (Tables 1 and 2).
The Special Olympians’ (n = 18) results revealed means and standard
deviations of 38.17 ± 9.64, 35.81 ± 9.03, and 33.61 ± 8.52 cm when tested in
the standard order of baseline, static, PNF, respectively. A 1-way ANOVA
revealed that all 3 means were significantly different (P < .05), indicating
that both static and PNF stretching interventions were effective in improving
participants’ stretching abilities from their baseline measures. When this
group was later tested in the reverse order (n = 17), with the static stretch
following the PNF stretch, it demonstrated significantly different (P < .05)
means and standard deviations of 39.00 ± 8.85, 35.29 ± 8.80, and 37.00 ±
9.85 cm, respectively, revealing an actual decrease in stretching performance
after the static stretch.
The Scheffé post hoc analyses identified significant differences (P < .05)
between all 3 tests within each order (standard and reverse order). These
results suggest that the PNF stretching technique was more effective in
improving the stretching performance of these Special Olympians than
was the static stretching technique.
Table 1 Flexibility Measures for the Baseline-Static-PNF
Sequence*
Group
With MR (n = 18)
Without MR (n = 44)
Baseline
38.17 ± 9.64
25.08 ± 11.49
Static
35.81 ± 9.03
22.51 ± 10.88
PNF
33.61 ± 8.52
19.51 ± 10.49
Scheffé Post Hoc Comparisons (F)
Baseline-static
14.06‡
43.05‡
Baseline-PNF
52.35‡
202.37‡
Static-PNF
12.15‡
58.74‡
*MR indicates mental retardation. Because of the orientation of the ruler on the sit-and-reach
flexibility box, decreasing scores demonstrate an increase in flexibility.
†P < .05. ‡P < .01.
28
Stopka et al
Table 2 Flexibility Measures for the Baseline-PNF-Static
Sequence*
Group
With MR (n = 17)
Without MR (n = 44)
Baseline
39.00 ± 8.85
24.30 ± 10.14
PNF
35.29 ± 8.80
20.20 ± 9.15
Static
37.00 ± 9.85
20.30 ± 9.07
Scheffé Post Hoc Comparisons (F)
Baseline-PNF
18.74‡
92.31‡
Baseline-static
5.46‡
87.25‡
PNF-static
3.97†
0.07
*MR indicates mental retardation. Because of the orientation of the ruler on the sit-and-reach
flexibility box, decreasing scores demonstrate an increase in flexibility.
†P < .05. ‡P < .01.
The coaches without MR (n = 44) had means and standard deviations
of 25.08 ± 11.49, 22.51 ± 10.88, and 19.51 ± 10.49 cm for baseline, static, and
PNF stretches, respectively. Similar to the Special Olympians tested, a 1-way
ANOVA revealed significant differences (P < .05) when comparing the static
and PNF interventions with baseline. When the coaching group was later
tested in the reverse order (n = 44) with the static stretch following the PNF
stretch, it demonstrated significantly different (P < .05) means and standard
deviations of 24.30 ± 10.14, 20.20 ± 9.15, and 20.30 ± 9.07 cm, respectively.
Scheffé post hoc analyses identified significant differences (P < .05) between the baseline and PNF stretching distances, as well as the baseline and
static stretching distances. No significant difference (P > .05) was identified,
however, between the PNF and static stretches—nearly half the participants
in the group without MR actually decreased in stretching ability when the
static stretch followed the PNF stretch.
Comment
As suggested by Mann and Jones8 and Mitchell,39 increases in stretching
ability and resultant increases in the body’s core temperature might result
in increases in the ability to perform activities of daily living and decreases
in the incidence of injury, low back pain, and emotional tension. With the
ease and pain-free nature of PNF stretching, in contrast to the discomfort
Static/PNF Techniques on Special Olympians and Coaches
29
associated with static stretching, it becomes necessary to examine the improvements made on application of these 2 techniques.
The purpose of this investigation was to examine the effects of static
and PNF stretching interventions on the stretching performance of Special
Olympians with MR and their coaches without MR. Both groups were
tested using the standard static stretching technique, as well as the PNF
hold-relax stretching technique. Each participant performed the stretches
in the 2 orders of baseline, static, PNF and baseline, PNF, static.
As was expected, for both groups the data analysis revealed significant
improvements in stretching scores when the static stretch and PNF stretch
were individually compared with the baseline measure. It was therefore
concluded that stretching in any manner resulted in a temporary increase
in stretching performance.
Static vs Baseline
Looking specifically at the increase in scores demonstrated on performance
of static stretching in both groups tested, it was noted that when static
stretching was performed, improvements in flexibility scores occurred. As
discussed by DePino et al,3 however, gains in stretching ability as a result of
static stretching are transient, lasting for only 6 minutes after administration
and then decreasing with time. Therefore, static stretching is an effective
technique when temporary gains in stretching ability are desired but might
not be effective in actually increasing connective-tissue extensibility for
an extended period of time. Because static stretching has been taught in
physical education classes, athletic settings, and the classroom for so long,
it has been assumed that the application of a static stretch is the best way
to increase overall flexibility. According to our findings, this does not hold
true when static stretching follows PNF stretching.
PNF vs Baseline
Examination of the results of PNF stretching revealed similar improvements
in stretching scores when compared with baseline measures. Because the
PNF stretching technique requires a certain amount of instruction on the
part of the physical educator, fitness instructor, or athletic trainer, concerns
arise as to the safety of this stretching technique when administered to individuals with MR. Mitchell39 discussed the need for the cognitive abilities of
the participant to be great enough to comprehend the instructions on how
to perform PNF stretching successfully. The present study, however, using
a sample of Special Olympians with mild to moderate MR, demonstrated
the ease of instructing individuals in effective PNF stretching. The modified PNF technique performed employs a towel to provide the necessary
resistance, thus negating the need for a partner and eliminating the need
for the expensive and time-consuming assistance of a knowledgeable educator or therapist.
30
Stopka et al
Baseline-Static-PNF Order
When tested in the order of baseline, static, PNF, both groups exhibited
significant improvements in stretching performance when comparing the
PNF stretch with the static stretch. Therefore, after static stretching resulted
in significant improvements over their baseline measures, participants
actually exhibited another significant increase in stretching ability after
performing a PNF stretch.
Baseline-PNF-Static Order
In order to examine the notion of an advantage of location of technique in
the stretching order, each participant later performed the stretches in the
order of baseline, PNF, and static. Results demonstrated that in this sample
of Special Olympians, stretching performance actually decreased when the
static stretch was performed last. Although the static stretch did result in an
increase in stretching performance as compared with the baseline, it did not
elicit a further increase after the PNF stretch had been performed, actually
eliciting a significant decrease in stretching performance as compared with
the previous PNF stretch.
The group without MR demonstrated no significant difference between
the PNF and static stretches, suggesting that the static stretch had, at best,
a neutral effect when performed after the PNF stretch. Further examination
of the data revealed that nearly half the participants actually decreased in
their stretching performance on administration of the static stretch (after the
PNF stretch). Again, the static stretch was found to be significantly different from the baseline measure but was ineffective in improving stretching
scores once the PNF stretch had been performed.
In summary, the results of this investigation demonstrated that the administration of a static stretch is effective in increasing temporary stretching
ability when compared with a baseline measure. Likewise, the application
of a PNF stretch was found to be effective in increasing an individual’s
stretching performance over baseline. When static stretching was applied
after PNF stretching, the group without MR demonstrated no improvement
in stretching scores and the Special Olympians actually decreased in stretching performance. When PNF stretching was applied after static stretching,
however, both groups improved in stretching performance as compared
with baseline and the previously performed static stretch.
Finally, the increases in stretching ability demonstrated after PNF stretching appear to outweigh the increases demonstrated by static stretching.
Based on the results of this study, PNF stretching appears to be an easy
method that can be explained, demonstrated, and performed by individuals
of various ages and cognitive abilities and therefore could be generalized to
a vast population of active individuals. With the pain-free, easy technique
used in this investigation, PNF stretching can be used in a wide array of
settings in which increased stretching ability is desired.
Static/PNF Techniques on Special Olympians and Coaches
31
Results indicated that individuals with (and without) mild to moderate MR can realize significant improvements in stretching performance
through the use of static and PNF stretching, with the PNF technique
producing more favorable results overall. Improvements in sit-and-reach
scores, when compared with baseline, occurred after either technique was
used. Furthermore, when the PNF technique was performed after the static
technique, stretching performance in both groups improved.
The improvements in stretching performance experienced through PNF
have a practical impact, because this technique offers a seemingly more
effective, and more efficient, pain-free alternative. This study furthermore
demonstrated that the hold-relax PNF stretching technique can be taught
to individuals with MR in a concise and comprehensible manner. Because
of the ease of use of the modified PNF technique used in this study, people
with and without disabilities might be apt to stretch more often, as is encouraged in the literature.1,9,35,57 Further studies are needed to corroborate
these findings and shed more light on the practicality of encouraging the
use of PNF stretching for everyone.
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