Medical
Communication
Biosci. Biotech. Res. Comm. 11(3): 518-522 (2018)
Effect of time and frequency of static stretching on
exibility of rectus femoris muscle of human subjects
Pooja Chaudhuri
1
and Nilo. Z. Kiba
2
1
Research Scholar, Department of Physiotherapy, Shri Jagdishprasad Jhabarmal Tibrewala University, Churela
Rajasthan
2
Assistant Professor, Department of Physical Medicine and Rehabilitation, Composite Regional Centre,
Guwahati Assam
ABSTRACT
The main aim of present study is to evaluate and compare the effect of frequencies and durations of static stretching on  exibility
of rectus femoris muscle of human subjects. A sample of 50 volunteers having tightness of rectus femoris muscle was randomly
allocated into  ve groups. Static stretching of rectus femoris muscle was performed in  ve different frequency and durations for 6
weeks. Group A (n=10) was subjected to 3 stretches for 30 seconds each once for 5 days in a week for 6 weeks. Group B (n=10) was
given 3 stretches for 15 seconds each for 6 weeks. Group C (n=10) was given 1 stretch for 30 seconds. Group D (n=10) was given 1
stretch for 15 seconds. Group E ( n=10) was given no stretch. The  ndings revealed that there was statistically signi cant increase in
ROM(knee  exion)in rst four groups A,B,C and D except Group E following the treatment with different parameters of time and fre-
quency of static stretching during 6 weeks with mean difference = 6.60 (pre-interventionmean value & S.D of ROM=125.80±3.645&
post-intervention mean=132.40±3.502), mean difference = 3.60 (pre-intervention mean=125.60±3.718 & post-intervention
mean=129.20±3.718), mean difference=6.40 (pre-intervention mean=125.20 ± 4.104 & post-intervention mean=131.60±4.006),
mean difference=3.60 (pre-intervention mean = 126.30±3.773 & post-intervention mean =129.90±3.479) & mean difference=
0.60 (pre-intervention mean = 125.10±3.784 & post-intervention mean = 125.70±3.561) respectively. Hence, the study exhibited
stretching of rectus femoris muscle three or once for 30 seconds appears to be effective and showed signi cant improvement com-
pared to 3 or 1 stretch for 15 seconds or no stretching. The results of Tukey test indicated that there is no signi cant difference
between 1 stretch or 3 stretch for 30 second. The results of the present study showed that a one 30 –second duration is an effective
amount of time to sustain a rectus femoris muscle stretch in order to increase ROM. No increase in  exibility occurred when the
frequency of stretching was increased from one to three times per day.
KEY WORDS: FLEXIBILITY, RECTUS FEMORIS MUSCLE, STATIC STRETCHING, MUSCLE PERFORMANCE
518
ARTICLE INFORMATION:
*Corresponding Author: dr.poojachaudhuri@gmail.com
Received 1
st
July, 2018
Accepted after revision 25
th
Sep, 2018
BBRC Print ISSN: 0974-6455
Online ISSN: 2321-4007 CODEN: USA BBRCBA
Thomson Reuters ISI ESC / Clarivate Analytics USA and
Crossref Indexed Journal
NAAS Journal Score 2018: 4.31 SJIF 2017: 4.196
© A Society of Science and Nature Publication, Bhopal India
2018. All rights reserved.
Online Contents Available at: http//www.bbrc.in/
DOI: 10.21786/bbrc/11.3/23
Pooja Chaudhuri and Nilo. Z. Kiba
INTRODUCTION
Flexibility is de ned as “the ability of a muscle to
lengthen, allowing one joint (or more than one joint
in a series) to move through a range of motion (ROM)
(Bandy et al., 1994,1998) Roberts et al 1999) and a loss
of muscle  exibility as “ a decrease in the ability of the
muscle to deform,” resulting in decreased ROM about
a joint. (Bandy et al., 1997, Russell et al., 2004). It is
believed that stretching can prevent injury (Zachezewski
et al.,1989 Hubley et al., 1984) enhance athletic per-
formance (Anderson et al., 1991,. Beaulieu et al., 1981,
Worrell 1994) and assist in rehabilitation following mus-
culoskeletal injury (Agre et al.,1985). Stretching is tradi-
tionally used as part of warm up to improve  exibility
(Shellock et al., 1985, McMillian et al 2006, Dalrymple
et al 2010, Page 2012).
The literature document three methods of stretching
exercises to increase  exibility: ballistic stretching, static
stretching and PNF techniques. All three methods have
been documented to increase ROM immediately after
stretching. (Russell et al., 2004, Sady et al 1982).
Propri-
oceptive neuromuscular facilitation involves the use of
brief isometric contractions of the muscle to be stretched
before statically stretching the muscle. This technique
not only requires expertise to perform but also requires
one-on–one intervention with another experienced indi-
vidual. Static stretching is performed by placing muscles
at their greatest possible length and holding that posi-
tion for a period of time (Beaulieu et al., 1981, Ander-
son et al., 1991,Russell et al., 2004). Ballistic stretch uses
bouncing or jerking movements imposed on the muscles
to be stretched. The quick, jerking motion that occurs
during the ballistic stretch can theoretically exceed the
extensibility limits of the muscle in an uncontrolled
manner and cause injury. The use of ballistic technique,
therefore, has not been widely supported in the literature
(Ferreira et al, 2007 & Torres et al, 2008).
Although documentation exists that static, ballistic,
and PNF techniques will increase the  exibility of mus-
cle, (Sady et al., 1982, Moore et al., 1980), but the most
widely used method for increasing ROM because of the
simplicity of execution and lower potential for tissue
trauma. An ample volume of literature has focused on
the effects of stretching on the  exibility of the ham-
strings muscle. However,there is a scarcity of evidence
of stretching on other muscle groups, such as the gas-
trocnemius, soleus, quadriceps and triceps surae, (Bandy
et al., 1997, Russell et al., 2004). Rectus femoris is the
only muscle in the quadriceps group that is involved
in hip  exion, since it originates in the pelvis and not
the femur. Isolated rectus femoris (RFM) tightness is
associated with a variety of clinical disorders. Rectus
femoris tightness may lead to alteration in swing phase,
increased energy expenditure and pain during walking
downstairs or when wearing high heels, ( Csink et al.,
1963, Lenart et al., 1974, Lateur et al., 1978 Richard et
al., 1985).
Another important point of consideration in the pre-
sent study is the effect of time and duration of stretching
on  exibility of rectus femoris muscle. The duration and
frequency of muscle stretching may interfere with the
improvement of  exibility.While the literature is unani-
mous in its support for static stretching resulting in
increased ROM, no consistency is apparent with regard
to how long stretches (time) and how much stretches
(frequency) should be held to obtain optimum bene ts.
Some researchers suggested that the 30 s duration of
stretching with one or three times a day is effective
for increasing muscle  exibility (Marques et al., 2009).
However, other studies recommended that the duration
of stretching in  exibility training programmers range
from 5 to 60 seconds,yet justi cations for these selec-
tions have largely been absent (Roberts et al., 1999)
The purpose of study was to determine the time
and frequency of static stretching that most effectively
increase  exibility of the rectus femoris muscles, as
measured by active knee  exion test.The effects of  ve
daily frequencies and durations of static stretching on
rectus femoris muscle  exibility was compared 5 days
per week for 6 weeks: (1) three 15 – second stretches (2)
one 30 – second stretch (3) one 15- second stretch (4) a
control (no stretching activity).The main objective of this
work was to determine the optimal time and frequency
of static stretching to increase  exibility of rectus femo-
ris muscle, as measured by active knee  exion test.
MATERIALS AND METHODS
The present study was an experimental study (3 5 fac-
torial designs), performed in the Research lab of Depart-
ment of Physiotherapy at Shri Jagdishprasad Jhabarmal
Tibrewala University, Rajasthan. The Institutional Ethi-
cal Committee approved the study, where prior to par-
ticipation in the study, subjects were explained about
the procedures that they would have to follow during
the study. The patients’ consent was taken on the con-
sent form for participation in the study. All the subjects
were the residents of Rajasthan, who volunteered for the
study and were randomly allocated into  ve groups. The
size of the sample was 50 subjects with 10 samples each
in group A,B,C,D and E. Subjects of either genderaged20
to 30 years having unilateral (right side) tightness of
rectus femoris muscle with no history ofback pain, uri-
nary tract infection, soft tissue injury, fracture of lower
limb, in ammatory joint & arthritic condition of lower
limb with acute or chronic rectus femoris injury were
BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS EFFECT OF STATIC STRETCHING ON RECTUS FEMORIS MUSCLE 519
Pooja Chaudhuri and Nilo. Z. Kiba
recruited. The subjects must exhibit positive knee  ex-
ion test with positive knee  exion ROM between 120-
130 ± 2 degree. In addition, subjects should not have
involved in any lower extremity stretching exercises
during 6 week study. The list of variables include time
and frequency of static stretching,  exibility of rectus
femoris. Universal goniometer with a double – armed,
full – circle protractor made of metal was used for all
measurements. Rectus femoris muscle  exibility using
active knee  exion test of each subject was measured
prior to assignment to groups and the reading for ROM
were taken once after 6 weeks of intervention. The sub-
ject was placed prone, with both feet off the end of the
examination table. The knees were extended and the hips
positioned in 0 degrees of  exion, extension, abduction,
adduction, and rotation.
The hip was stabilized to maintain the neutral posi-
tion. The hip was not allowed to  ex, a cloth strap was
then placed securely across the buttocks to stabilize the
hips in extension, when the strap was tightened the
subject was instructed to adjust his body to a comfort-
able prone position, because tightening the strap caused
the trunk and hips to rotate. With the hips stabilized in
extension and the ankle relaxed in plantar exion over
the edge of the table, the subject was told to slowly bend
his knee to the point of “initial resistance”. When the end
point was reached, the degree reading of knee  exion
using universal goniometer was observed and recorded.
Following the initial measurements, subjects were
randomly assigned to one of  ve groups. Subjects
assigned to group 1 (6 men, 4 women mean age = 24.70
years,SD= 2.60) did three 30 seconds static stretches (10
seconds between stretches) of the rectus femoris muscle.
Group 2 (6 men,4 women mean age = 24.30 years, SD
= 3.12) did three 15 second static stretches, with a 10
second rest between stretches. Group 3 (4 men, 6 women
mean age = 24.40 years, SD= 2.79) did one static stretch
for 30 seconds. Group 4 (4 men, 6 women mean age
=24.40 years, SD = 3.27) did one static stretch for 15 sec-
onds. The  fth group (6 men, 4 women mean age=24.50
years, SD= 2.87) served as a control group and did no
stretching activities.
Subjects in group 1 through 4 stretched 5 days a week
for 6 weeks.To stretch the rectus femoris muscle, each
subject stood upright with one hand against a wall for
balance under supervision of the therapist. The knee was
exed and the hip extended, the lumbar spine and pel-
vis were aligned in a neutral position. The pelvis did
not tilt anteriorly nor the low back hyperextend; the hip
was not abducted or remained  exed. When the subject
did self- stretching ,the trunk was erect,not slumped.
the subject then  exed the dominant leg to a knee joint
angle as possible. and the stop watch was used to calcu-
late the accurate timing (30,15 and 10 sec).
After that all subjects were retested after 6 weeks
using same procedures described for the pretest.
RESULTS AND DISCUSSION
The results have been explained under the following
sub-headings: 1) Effect of static stretching on  exibility
of rectus femoris muscle in term of ROM (knee  exion)
with different parameters of time and frequency during
6 weeks:
The primary objective of the current study was to
investigate the effect of time and frequency with differ-
ent parameters of static stretching on the  exibility of
rectus femoris muscle. Therefore 4 different parameters
of static stretching were administered for the duration of
six weeks, namely 3 stretches for 30 seconds, 3 stretches
for 15 seconds, 1 stretch for 30 seconds and 1 stretch
for 15 seconds once for 5 days in a week. The  nd-
ings revealed that except the control group, all the four
groups showed statistically signi cant improvement in
muscle  exibility.
Stretching the rectus femoris muscle at 3 or 1 stretch
for 30 seconds appeared to be effective and showed sig-
ni cant improvement compared to 3 or 1 stretch for 15
seconds or no stretching (control). As indicated by the
Tukey test,there is no signi cant difference between 1
stretch or 3 stretch for 30 seconds. Therefore, 1 stretch
for 30 second is a suf cient stretch to increase the  ex-
ibility of rectus femoris muscle. The results of this study
are consistent with the results of another study con-
ducted by Bandy et al., 1994 comparing the effect of
time and frequency with different parameters of static
stretching on hamstring muscles,in which stretching for
30 second one or three times per day for 5 days per week
for 6 weeks was more effective for increasing muscle
exibility than no stretching. There was no difference
between stretching one or three times per day using
either a 30 – or 60 – second duration of stretching. The
use of longer duration and more frequent daily stretch-
ing, therefore must be questioned.
Gains in  exibility involve biomechanical,neurological
and molecular mechanisms that determine myo brillo-
genesis as a long-term result.The gains in  exibility can
also be associated with increased tolerance to pain and
increased viscous elastic properties of the muscle-tendon
units. Several studies have reported  exibility and ROM
after stretching programs and the present results support
these  ndings.The results of this study,in conjunction
with previous research ,showed that the increased the
duration and frequency beyond one 30 –second stretch
performed one time per day did not increase  exibility
and it indicated that 30 seconds is an effective length
of time to sustain a rectus femoris muscle stretch in
520 EFFECT OF STATIC STRETCHING ON RECTUS FEMORIS MUSCLE BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS
Pooja Chaudhuri and Nilo. Z. Kiba
FIGURE 1. Depicts the Pre and Post values of ROM of Knee in  exion in different groups
Table 1. Pre and Post intervention comparison among  ve groups; Group A, B, C, D and E
Groups A (n=10) B (n=10) C (n=10) D (n=10) E (n=10)
Mean± SD Mean± SD Mean± SD Mean± SD Mean± SD
Pre- values 125.80±3.645 125.60±3.718 125.20±4.104 126.30±3.773 125.10±3.784
Post-values 132.40±3.502 129.20±3.718 131.60±4.006 129.90±3.479 125.70±3.561
Mean difference 6.60 3.60 6.40 3.60 0.60
Table 2. ANOVA analysis of ROM (knee  exion) for all  ve groups.
Variable Sources of Variation SS Df MS F-ratio Signi cance
Range of motion (ROM)
Between 242.72 4 60.68
195.0429 Signi cant
Within 14 45 0.311111
Table 3. Pair wise comparison of group
means in all  ve groups in term of ROM
(knee  exion) during 6 weeks
A
B
C
Signi cant B
Non-Signi cant Signi cant C
order to increase ROM.This observation is clinically
relevant,suggesting that one 30 –second stretch per-
formed  ve times a week is suf cient to improve  ex-
ibility compared to stretching at a higher frequency.
This study contrasts with the  ndings of Bandy and
Irion (1998) who found stretching durations of 30 and 60
seconds to be more effective than 15 seconds. However,
in the study of Bandy and Irionthere is no indication
whether total amount of time spent in a stretch position
during the entire training programme was controlled.
This factor, if not controlled, could explain the differ-
ences observed subjects in the longer duration treatment
groups would be exposed to more time in a stretched
position and therefore likely to show greater improve-
ments. The present study did control the total amount
of time spent in a stretched position during the entire
training programme.a stretching duration of 15 seconds
resulted in signi cantly smaller improvements in active
ROM than a duration of 30 seconds, suggesting that 15
seconds may not be long enough to elicit a Golgi tendon
organ response.
BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS EFFECT OF STATIC STRETCHING ON RECTUS FEMORIS MUSCLE 521
Pooja Chaudhuri and Nilo. Z. Kiba
Another study of Bandy et al showed that 30-sec-
ond static stretch performed one time per day over a
6 week period resulted in more than twice the gains in
hamstring  exibility than performing dynamic range of
motion at the same frequency and duration. Only few of
the studies have been done on the  exibility of rectus
femoris. Therefore, such studies contribute little toward
understanding the mechanisms behind the acquired
increase in ROM after stretching.
CONCLUSION
Our study demonstrated that although stretching for 30
seconds one or three times per day for 5 days per week
for 6 weeks was more effective for increasing muscle
exibility (as determined by increased knee  exion
ROM) than no stretching or 15 sec stretch, there was
no difference between one or three times per day using
30 – second duration of stretching. Therefore, 30 – sec-
ond duration is an effective amount of time to sustain a
rectus femoris muscle stretch in order to increase ROM.
The results from this study will be helpful for individuals
who desire to increase their  exibility in an attempt to
decrease injury and enhance performance, as well as for
those clinicians who incorporate static stretching activi-
ties as part of their rehabilitation programs.
REFERENCES
Agre JC (1985). Hamstring injuries: Proposed etiological fac-
tors, prevention, and treatment. Sports Medicine ; Vol. 2(1):
Pages 21-33.
Anderson B, Burke ER (1991). Scienti c medical and practical
aspects of stretching. Clinics in Sports Medicine; Vol. 10(1):
Pages 63-86.
Bandy WD, Irion JM (1997).The effect of time and frequency of
static stretching on  exibility of the hamstring muscles. Physi-
cal Therapy; Vol. 77(10): Pages 1090-1096.
Bandy WD, Irion JM (1994). The effect of time on static stretch
on the  exibility of the hamstringmuscle. Physical Therapy;
Vol. 74: Pages 845-850.
Bandy WD, Irion JM (1998). The effect of static stretch and
dynamic range of motion training on the  exibility of the
hamstrings muscles. Journal of Orthopaedic & Sports Physical
Therapy; Vol. 51: Pages 637-663.
Beaulieu JE (1981). Developing a stretching program. The Phy-
sician and Sports Medicine; Vol. 9 (11): Pages 59-65.
Csink L,Imre J (1963). Isolated contracture of the rectus femo-
ris muscle. Clinical Orthopaedics; Vol. 45 B,no 1.
Dalrymple KJ, Davis SE, Dwyer GB, Moir GL. (2010) Effect of
static and dynamic stretching on vertical jump performance in
collegiate women volleyball players. The Journal of Strength
and Conditioning Research; Vol 24(1): Pages 149–15
De Lateur BJ, Stonebridge JB (1978). Fibrous muscular con-
tractures: Treatment with a new direct contact microwave
applicator operating at 91 MHz. Archives of Physical Medicine
and Rehabilitation t; Vol. 59(10): Pages 488-99.
Ferreira GN, Teixeira-Salmela LF, Guimaraes CQ (2007) Gains
in  exibility related to measures of muscular performance:
impact of  exibility on muscular performance. Clinical Jour-
nal of Sport Medicine; Vol.17(4): Pages 276–281
Hubley CL, Kozey. JW (1984). Can stretching prevent athletic
injuries? Journal of Musculoskeletal Medicine; Vol. 7(3)19:
Pages 25-34.
Jennifer M Roberts, Karen Wilson (1999). Effect of stretching
duration on active and passive range of motion in the lower
extremity. British Journal of Sports Medicine; Vol. 33(4): Pages
259-263.
Lenart , Kullman (1974) Isolated contracture of the rectus fem-
oris muscle. Clinical Orthopaedic; Vol. 99: Pages 125-130.
Marques AP, Vasconcelos AA (2009). Effect of frequency of
static stretching on  exibility, hamstring tightness and electro-
myographic activity.Brazilian Journal of Medical and Biologi-
cal Research, Vol. 42(10): Pages 949-53.
McMillian DJ, Moore JH, Hatler BS, Taylor DC. (2006) Dynamic
vs. static-stretching warm up: the effect on power and agil-
ity performance. The Journal of Strength and Conditioning
Research; Vol.20(3):Pages 492–499
Moore M, Hutton R (1980). Electromyographic investigation of
muscle stretching techniques. Medicine & Science in Sports &
Exercise; Vol. 12(5): Pages 322-329.
Page P (2012 ) Current concepts in muscle stretching for exer-
cise and rehabilitation. International journal of sports and
physical therapy;Vol 7(1) : Pages 109–119.
Gajdosik R (1985). Rectus femoris muscle tightness: Intratester
Reliability of an Active Knee Flexion test Journal of Orthopae-
dic & Sports Physical Therapy; Vol. 6(5): Pages 289-292.
Russell T. Nelson, William D. Bandy (2004). Eccentric Training
and Static Stretching Improve Hamstring Flexibility of High
School Males. Journal of Athletic Training; Vol. 39(3): Pages
254-258.
Sady SP, Wortman M (1982). Flexibility training: ballistic, static
or proprioceptive neuromuscular facilitation? Archives of Phys-
ical Medicine and Rehabilitation; Vol. 63(6): Pages 261-263.
Shellock FG, Prentice WE (1985). Warming up and stretching
for improved physical performance and prevention of sports
–related injuries. Sports Medicine; Vol.2 (4): Pages 267-278.
Torres EM, Kraemer WJ, Vingren JL (2008)Effects of stretching
on upper-body muscular performance. The Journal of Strength
and Conditioning Research; Vol.22(4): Pages 1279–1285
Worrell TW, Smith TL, Winegardener J (1994). Effects of ham-
string stretching on hamstring muscle performance.Journal of
Orthopedics Sports Physical Therapy; Vol.20(3): Pages 154-159.
Zachezewski JE (1989). Improving  exibility.In:Physical Ther-
apy. Philadelphia, Pa :JB Lippincott Co: Pages 698-699.
522 EFFECT OF STATIC STRETCHING ON RECTUS FEMORIS MUSCLE BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS