Total Daily Stretch Time Article
I’m Not sure about the Copy-write stuff regarding this article.
(so let me know how that works). I am a Personal Trainer so I have access to this.
I believe it may have some impact on duration of stretching/hanging.
There is alot of scientific/statistical mumbo-jumbo but I left that in to give it some validity.
I know the long Paragraph’s may be difficult on the eyes but that is how they are.
Journal of Strength and Conditioning Research, 2003
A Comparison of Two Stretching Protocols on Hip Range of Motion: Implications for Total
Daily Stretch Duration
ABSTRACT
It is theorized that the total stretch time in a day is more
important than the actual single stretch duration time. The
purpose of this study was to compare 2 stretching protocols,
keeping total stretching time equivalent. The 2 protocols
were a 10-second duration stretch and a 30-second duration
stretch. Although the stretch durations differed, the total
stretching time over the course of a day was held constant
at 2 minutes for both protocols. Participants were randomly
assigned a protocol to each of their legs: subjects stretched
1 leg with the 10-second protocol and the opposite leg with
the 30-second protocol. The 10-second stretch was repeated
6 times for a total of 1 minute; the 30-second protocol was
repeated 2 times for a total of 1 minute. Stretching was performed
twice daily (a total of 2 minutes each day) for 6
weeks. All stretching was performed to the hamstring muscles.
Hip flexion measurements were recorded at pretest, 3-
weeks, and 6-weeks. Subjects demonstrated significant gains
in range of motion for hip flexion over the course of 6 weeks,
p 5 0.000. No differences existed between the 2 protocols.
Range of motion gains were equal between the 2 stretching
protocols. The common denominator was total stretch time
for a day. Regardless of the duration of a single stretch, the
key to improvement was the total daily stretch time. These
findings are important as they allow clinicians and individuals
to customize stretching protocols to meet individual
needs.
Introduction
Stretching muscles, tendons, and other soft tissue is
a common practice among athletes, fitness enthusiasts,
and rehabilitation professionals. The reasons behind
stretching are twofold: to increase range of motion
of a body segment or to restore movement to a
previously injured or restricted area. In addition, athletes
may use stretching to enhance athletic performance
and reduce the risk of injury. Rehabilitation
professionals use stretching to assist individuals to regain
lost motion due to injury or immobilization. Although
the evidence is inconclusive as to the injury
prevention benefit of stretching, stretching can improve
range of motion and flexibility in healthy and
injured individuals (3, 7, 8, 10, 18).
Stretching is applied in many different forms, including
multiple variations of passive and active techniques.
In addition, protocols for stretching (i.e., duration
of stretch, number of repetitions per session,
number of sessions per day) are equally varied (4).
Kisner and Colby (10) present several different protocols
ranging from short duration stretches (i.e., 15–30
seconds) to long duration stretching (i.e., lasting greater
than 20 minutes at a time). Short duration stretching
is most common among athletes and fitness enthusiasts,
whereas the longer duration protocols are common
in the rehabilitation setting. Because short duration
stretching is more common in the public, this
study focused on the short duration protocol.
Research supports the notion that several repetitions
of the short duration stretch are most effective
for increasing range of motion and flexibility of the
involved segment (5, 6). However, research evidence is
not conclusive as to the optimal duration of a stretch.
Some investigations recommend a stretch duration of
at least 30 seconds, whereas others have recommended
shorter duration stretches, such as 15 seconds (6, 12).
For instance, Madding et al. (12) found that a 15-second
stretch was equally effective to gain range of motion
as 45-second and 2-minute duration stretches.
However, Bandy and Orion (1) contradicted these findings
by demonstrating that a 30-second stretch was
more effective than a 15-second stretch. They also
found that the 30-second stretch was as effective as a
longer 1-minute stretch. In addition, Bandy et al. (2)
Comparison of Two Stretching Protocols 275
Figure 1. Single leg stretching position for both protocols.
demonstrated that the 30-second stretch was superior
to a dynamic range of motion (DROM) stretching program
consisting of very short duration active stretches
(i.e., 5-second stretches) repeated multiple times in a
session. Thus based on these findings the standard
stretching protocol calls for stretches that last approximately
30 seconds in length.
A difficulty with these studies examining stretching
effectiveness is the fact that the total stretching
time in a session differed for the different protocols.
With the exception of the Bandy et al. (2) investigation
of the DROM protocol, subjects in previous studies
tended to spend more time stretching each day with
the longer duration protocols than with the shorter
duration protocols. In other words, subjects stretching
for a short duration (i.e., 15 or 30 seconds) tended to
stretch for less total time in a day compared with subjects
stretching with a long duration stretch (i.e., 1 or
2 minutes). It is not clear whether the differences in
effectiveness between the various protocols is a result
of the single stretch duration or a result of the total
time spent stretching in a session.
Recently, Roberts and Wilson (14) demonstrated
that the total amount of time stretching in a given day
may be more important than the actual hold time of
a stretch. In their investigation, they compared 2 different
stretch durations, 5 and 15 seconds, on active
and passive range of motion in the lower extremity.
Subjects were assigned to 1 of the 2 groups based on
the 2 protocols. Both groups stretched for the exact
same amount of time each day (i.e., 45 seconds). The
group stretching for 5 seconds repeated the procedure
9 times; the group stretching for 15 seconds repeated
the procedure 3 times. At the conclusion of 5 weeks,
the 2 groups demonstrated comparable gains in passive
range of motion. Roberts and Wilson (14) concluded
that the total time stretching in a day was the
important component for effective stretching protocols.
The purpose of this study was to test the findings
of Roberts and Wilson (14). However, we chose to compare
a 10-second duration stretch with a 30-second duration
stretch. The 30-second duration was chosen because
it was proven to be effective in previous research
(1, 2). A short 10-second duration was chosen for convenience
in terms of equating total stretch time each
day. As with Roberts and Wilson (14), all of our subjects
stretched for an equal total time each day (i.e., 2
minutes). We had 2 hypotheses. Our first hypothesis
was that no differences would exist between the 2 protocols
in the total range of motion gained at the conclusion
of 6 weeks of stretching. We further hypothesized
that both stretching protocols would yield gains
in hip flexion range of motion over time (i.e., at the
end of 6 weeks).
Methods
Subjects
Thirty-five healthy individuals volunteered to participate.
Subjects consisted of students and staff members
of the Medical College of Ohio. All subjects were free
from injury over the past 1 year. In addition, we
screened all potential subjects for hip range of motion.
Only subjects with hip flexion range of motion less
than 708 of hip flexion, using the straight leg raising
procedure (6), were included in this investigation. We
excluded 12 individuals based on this criterion. Twenty-
three subjects participated in this study, with 18
women and 5 men (mean age 5 22.8 years, SD 5 4.7,
range 5 21–43 years of age). All subjects signed an
approved informed consent form for the Medical College
of Ohio’s Institutional Review Board for Human
Subjects.
Stretching Protocols
Subjects performed all stretching exercises to the hamstring
muscles of the thigh. We instructed subjects in
a standing, 1-legged stretch of the hamstring. Figure
1 illustrates the stretching position. During the stretch,
individuals pushed into the position until they experienced
moderate discomfort in the posterior thigh.We
then instructed the subjects in each of the 2 stretching
protocols, the 30-second duration stretch and the 10-
second duration stretch. Table 1 contains the protocols
for both stretching procedures.
In each protocol, the total stretching time per session
was 1 minute. Each session was repeated twice a
day. The total stretching time each day was 2 minutes.
The length of time for each individual stretch distinguished
the 2 protocols. For the 30-second protocol,
each stretch was held for 30 seconds, followed by a
brief rest of 5 seconds. Subjects repeated the procedure
a second time, for a total of 60 seconds of stretching.
For the 10-second protocol, each stretch was held for
10 seconds, followed by a brief rest of 5 seconds. Subjects
repeated the procedure 6 times, for a total of 60
seconds of stretching. The number of repetitions of a
given stretch provided the equality in total stretching
time for a day.
Subjects drew a slip of paper marked either ‘‘right
5 30’’ or ‘‘right 5 10.’’ This process allowed for a random
assignment of the 2 stretching procedures to each
subject’s legs. Thus if an subject drew ‘‘right 5 30,’’
this subject performed the 30-second stretch to the
right leg and the 10-second stretch to the left leg. All
subjects stretched both legs, using a different protocol
on each leg. All subjects stretched the right leg first,
regardless of the protocol. Subjects stretched the appropriate
legs over a course of 6 weeks. In addition to
the stretching, subjects kept a daily log of their stretching
activities. We used the log as a means of assessing
compliance.
Measurement
Figure 2 illustrates the measuring position for hip
range of motion. We measured both legs of each subject
for straight leg raise range of motion at the hip.
We obtained measurements using a standard 12-inch
goniometer. The same individual, a licensed physical
therapist, performed all measurements. The physical
therapist took measurements on 3 occasions: pretest, 3
weeks, and 6 weeks. The physical therapist was blind
as to the condition for each leg. In addition, the physical
therapist repeated the measurements on 10 randomly
selected subjects to investigate measurement reliability.
Force of the movement to obtain the measurement
position was based on obtaining a firm end
feel or a report by the subject to stop.
Statistical Analysis
We estimated the reliability of the goniometry measurements,
with the single physical therapist, using
the intraclass correlation coefficient (ICC; 15). The ICC
for the pretest measures was 0.96, which is excellent
intrarater reliability.
In addition, this investigation involved a 2 3 3
(protocol 3 time) mixed model repeated measures design.
Subjects served as their own controls in this
study. We first examined potential interactions between
the treatment condition and time. In addition,
we examined the main effect for treatment and the
main effect for time. We used the multivariate approach
to repeated measures analysis (11, 13, 16). In
case of any main effects for the time variable, we used
pairwise comparisons with the Bonferroni adjustment
procedure (9, 17). Finally, we used polynomial contrasts
to examine the time trend of the data.
Results
The combined means for hip range of motion values
for both protocols across 3 times were 54.438 (SD 5
11.29, range 5 25–698); 70.368 (SD 5 15.28, range 5
41–1128); and 80.508 (SD 5 16.56, range 5 46–1158) for
the pretest, 3-week, and 6-week measures, respectively.
An interaction between methods and time was not
statistically significant (exact F 5 0.54; df 5 2,41; p 5
0.5889). In addition, the main effect for method was
not significant (exact F 5 0.13; df 5 1,42; p 5 0.7221).
The main effect for time was significant (exact F 5
99.51; df 5 2,41; p 5 0.0001). Table 2 contains the mean
values for each of the measurement conditions, along
with the overall mean for each time period (e.g., pretest,
3-week, and 6-week).
Polynomial contrasts revealed a significant quadratic
trend for time (F 5 6.21; df 5 1,42; p 5 0.0167),
* The mean differences are significant, p , 0.01.
Figure 4. Mean range of motion values for each protocol
over time (no differences between stretching protocols).
suggesting a decreasing effect of the stretching effects
over time. Figure 3 illustrates the trend of the data.
Pairwise comparisons for the main effect over time
revealed significant differences among all pairwise
comparisons, using 99% confidence intervals for differences.
Significant differences existed between the
measures taken at pretest compared with the measures
taken at 3 weeks (p , 0.01). In addition, there was a
significant difference between the measures taken at 3
weeks compared with the measures at 6 weeks (p ,
0.01). Finally, comparing the measures at pretest with
the measures at 6 weeks revealed a significant difference
(p , 0.01). Thus significant gains in hip range of
motion continued to occur over the duration of the 6
weeks of this study. Table 3 contains the mean difference
scores, SD, and the upper and lower bounds for
the 99% confidence limits.
Discussion
Stretching is an important component to exercise and
physical activity. In addition, rehabilitation professionals
rely on stretching as a method for restoring lost
motion and function. Although the literature supports
various stretching protocols (3–5, 7, 8, 10, 18), complete
consensus does not exist as to the most effective
method, particularly for short duration stretching. The
results of our investigation support the notion that the
total time stretching in a given day may be more important
than the actual duration of a single stretch repetition.
As with Roberts and Wilson (14), the overall
time duration appears to be a key factor influencing
stretching effectiveness. Regardless of whether a
stretch is held for 10 or 30 seconds, equal gains in
range of motion can be achieved with either technique
provided the individual stretches for the same total
time over the course of a day. In this investigation,
total stretch time was 2 minutes each day. A comparison
of the mean range of motion values for both
stretching protocols revealed no significant differences
between the 2 methods. However, both protocols resulted
in significant gains in the range of motion at
the hip (Figure 4).
In addition to the gains obtained over the course
of this investigation, the significant quadratic trend for
time indicates that rate of gain decreased over time.
This is evident by looking at the gain scores from pretest
values to the 3-week values compared with the
gain scores from the 3-week values to the 6-week values.
Subjects improved hip range of motion by approximately
168 from the beginning of the stretching
program until the 3-week measurement time. Subjects
gained approximately 108 from the time of the 3-week
measurement to the 6-week measurement time. This
polynomial trend suggests that range of motion gains
are more rapid in the first 3 weeks of a stretching program
and that the rate of gains gradually decreases
over time. Further research is needed to see if this
trend continues or if a linear trend resumes. Extrapolation
of further gains is not possible at this time.
Although all subjects performed both stretching
protocols (i.e., 1 protocol was assigned to each leg), we
do not feel that a crossover effect occurred. We were
not able to find sufficient evidence that performing a
single plane motion stretch to 1 side of the body has
any appreciable effect on the contralateral side.
The findings of this investigation, regarding the 2
different stretching protocols, may be useful for the
clinician (e.g., athletic trainer, physical therapist, personal
trainer) or coach when developing an exercise
program for an athlete, client, or patient. Clinicians
and coaches can design the stretching component of
the exercise program to suit the needs and abilities of
each individual. For individuals who tolerate long duration–
type stretching, the 30-second or longer protocol
may be best. However, for individuals who do not
tolerate the sensation of stretching, a shorter duration,
more frequent approach may be best suited for them.
In addition, the shorter duration approach may be
more effective for individuals who do not tolerate
stretching well. These individuals may inadvertently
reduce the stretching tension during long duration
stretches in an attempt to reduce the discomfort. With
the short duration stretch, individuals may be less likely
to reduce the intensity of the stretch. These suppositions
are purely theoretical and must be tested empirically
with a patient population.
Practical Applications
The purpose of this study was to test whether the total
stretching time in a given day was the key element for
effective stretching. We compared 2 stretching approaches,
a 10-second protocol to a 30-second protocol.
The common element between these 2 protocols
was the total time individuals stretched each day,
namely 2 minutes. The results of this investigation
support the notion that effective gains can be achieved
with either stretching approach provided the total
stretching time in a day was 2 minutes. Clinicians and
athletes are advised to consider using shorter duration
stretching approaches for individuals who do not tolerate
the sensation of stretching.
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Address correspondence to Daniel Cipriani, dcipriani@
mco.edu.
