Available online at www.sciencedirect.com
Manual Therapy 14 (2009) 167e172
www.elsevier.com/math
Original Article
Transient effects of stretching exercises on gait parameters
of elderly women
André L.F. Rodacki a,*, Ricardo M. Souza a, Carlos Ugrinowitsch b,1,
Fabiano Cristopoliski a, Neil E. Fowler c,2
a
Universidade Federal do Paraná, Setor de Cieˆncias Biológicas, Departamento de Educaç~
ao Fı´sica,
Centro de Estudos do Comportamento Motor. R. Coraç~
ao de Maria, 92, BR116, Km 95, Jardim Botânico, Curitiba, Paraná, Brazil
b
Universidade de S~
ao Paulo, Escola de Educaç~
ao Fı´sica e Esportes, Av. Mello Moraes, 65,
Cidade Universitária, Butant~
a, S~
ao Paulo, S~
ao Paulo, Brazil
c
The Manchester Metropolitan University, Department of Exercise and Sport Sciences, Centre for Biophysical and
Clinical Research into Human Movement, Hassall Road, Alsager, Stoke-on-Trent, England ST7 2HL, United Kingdom
Received 2 May 2007; received in revised form 18 December 2007; accepted 6 January 2008
Abstract
This study aimed to analyse the effects of a single stretching exercise session on a number of gait parameters in elderly participants in an attempt to determine whether these exercises can influence the risk of fall. Fifteen healthy women living in the community volunteered to participate in the study. A kinematic gait analysis was performed immediately before and after a session of static
stretching exercises applied on hip flexor/extensor muscles. Results showed a significant influence of stretching exercises on a number
of gait parameters, which have previously been proposed as fall predictors. Participants showed increased gait velocity, greater step
length and reduced double support time during stance after performing stretching exercises, suggesting improved stability and mobility. Changes around the pelvis (increased anterioreposterior tilt and rotation range of motion) resulting from the stretching exercises were suggested to influence the gait parameters (velocity, step length and double support time). Therefore, stretching exercises
were shown to be a promising strategy to facilitate changes in gait parameters related to the risk of fall. Some other gait variables
related to the risk of fall remained unaltered (e.g., toe clearance). The stable pattern of segmental angular velocities was proposed to
explain the stability of these unchanged gait variables. The results indicate that stretching exercises, performed on a regular (daily)
basis, result in gait adaptations which can be considered as indicative of reduced fall risk. Other studies to determine whether regular
stretching routines are an effective strategy to reduce the risk of fall are required.
Ó 2008 Elsevier Ltd. All rights reserved.
Keywords: Risk of fall; Gait; Stretching exercises
1. Introduction
Trauma resulting from falls in the elderly is one of
the most significant causes of injury and death (Blake
* Corresponding author. Tel.: þ55 41 3360 4333; fax: þ55 41 3360
4336.
E-mail address: [email protected] (A.L.F. Rodacki).
1
Tel.: þ55 11 3091 2143.
2
Tel.: þ44 0161 247 5491; fax: þ44 0161 247 6375.
1356-689X/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved.
doi:10.1016/j.math.2008.01.006
et al., 1988; Cameron and Quine, 1994), with annual
costs estimated of $10 billion (Campbell et al., 1989).
Although less than 2% of falls among the elderly result
in a hip fracture, more than 90% of hip fractures occur
as a consequence of a fall. In addition, fall injuries in
the elderly usually demand longer hospitalization periods and may lead to seriously impaired mobility
and an important decline on functional ability after
recovery (Cameron and Quine, 1994) that may result
in social isolation, loss of independence and need of
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A.L.F. Rodacki et al. / Manual Therapy 14 (2009) 167e172
care assistance (Andersson and Schultz, 1979; Cameron
and Quine, 1994).
The largest number of hip fractures results from a fall
occurring during locomotion in which extrinsic and
intrinsic factors play a role. Extrinsic factors are associated with environmental hazards such as slippery
surfaces, while intrinsic factors are individual-related.
Intrinsic factors have been pointed as the best fall predictors among elders (Honeycutt and Ramsey, 2002)
and include physiological, medical problems, medication
and alcohol use.
Muscle weakness, as a result of a natural decrease in
muscle mass with aging, has been considered as a major
cause of falls (Cummings et al., 1990). In general, falls
have been strongly associated with decreased physical
activity and impaired mobility measurements (body
sway and gait). Reduced range of motion, as a consequence of the muscleetendon unit and surrounding connective tissue stiffness, has been indicated to assume
a positive relationship to fall incidence (Guimar~aes
and Farinatti, 2005). Other investigations have indicated
that reduced range of motion, specifically about the hip
and the ankle joints, constitutes one of the main causes
of fall due to the influence that hip rigidity has over the
lower limb dynamics during walking (Rose and Gamble,
2006). Kerrigan et al. (2001) proposed that a reduction
in hip joint mobility is one of the most important age-related factors influencing the walking pattern. It has been
shown that peak hip extension during walking is consistently lower in both elderly fallers and non-fallers than
in young adults, irrespective of the walking speed. As
peak hip extension is influenced by the tightness of the
antagonistic muscles, specific hip flexor stretching exercises may be an attractive possibility to improve walking
performance in the elderly and reduce the risk of falls
(Kerrigan et al., 2001).
Kerrigan et al. (2001) showed that fallers are characterized by exaggerated hip tightness. Kerrigan et al.
(2003) showed a non-significant increase in peak hip extension during gait performance as a result of a 10 week
unsupervised exercise programme. The failure to find
a significant effect may be related to the poor adherence
and control of the exercise practice. Indeed King et al.
(2002) have shown that controlled, centre-based exercises are more effective than when practiced at home
(unsupervised). It remains to be seen whether correctly
performed stretching exercise affects gait parameters.
If one considers that the outcome of long-term exercises is a cumulative response of successive training sessions, analyzing the transient effect produced by a single
session may constitute an interesting alternative to understand the long lasting effects of stretching training
programs. Indeed, stretching exercises have been shown
to produce acute changes in joint range of motion
(Taylor et al., 1990; McHugh et al., 1992; Halbertsma
and Goeken, 1994; Willy et al., 2001). This acute effect
may provide additional amplitude at the hip joint and
reverse some changes in gait pattern that characterises
aging (e.g., increase step length). Therefore, the present
study aimed to analyse the immediate effects of a session of static stretching exercises for the hip flexor muscle group over the gait and a number of parameters
that have been related to the risk of fall in elderly
participants.
2. Methods
Fifteen healthy women (age: 64.5 3.2 years; height:
1.59 0.09 m; body mass: 77.3 8.2 kg) living in the
community volunteered to participate. The study was
approved by the University’s ethic committee and all
participants were informed of the inherent risks and
benefits, before signing an informed consent form. Participants with problems that could affect their ability to
walk (e.g., lower limb surgery, low back pain, previous
fractures, arthritis, etc.) were not included in the study.
Male participants were also not included due to viscoelastic differences between genders (Kubo et al., 2002).
An interview revealed that participants were able to
perform their regular daily activities with no assistance
but were not involved in systematic physical activities
programs during the last six months that preceded the
present study. Participants reported no fall history
during the last 12 months that preceded the experiment.
To determine the effect of one stretching session on
the gait pattern, participants performed one experimental session. A kinematic gait analysis was conducted
before (PRE) and immediately after (POS) one set of
specific static stretching exercises for the hip flexor muscle group on both limbs. During the exercise, participants remained lying on their back with both lower
limbs hanging from the edge of a padded surface.
Stretching was applied by one of the experimenters by
flexing one thigh towards the trunk at approximately
45 with respect to the horizontal, while a second experimenter moved the contralateral thigh downwards causing hip hyperextension. Then, the knee of the stretched
leg was taken into flexion. The experimenter sustained
a position in which participants reported the first symptoms of muscle discomfort for 60 s. Exercises were repeated four alternate times in each leg (240 s in each
limb). Static exercises were applied because they have
been proved to provide satisfactory results in groups
of elderly individuals (Feland et al., 2001a; Ferber
et al., 2002). Fig. 1 represents the stretching procedures.
Immediately after the stretching procedures, participants were requested to walk in the laboratory area to
have their gait filmed. Participants were allowed to
walk in the walkway a few of times (4e6 trials) in an
attempt to familiarise them with the protocol used in
the experiment. The interval between the end of the
A.L.F. Rodacki et al. / Manual Therapy 14 (2009) 167e172
169
Fig. 1. Schematic representation of the stretching exercise. The non-stretched thigh was flexed towards the trunk segment approximately 45 with
respect to the horizontal (A) while the other limb (stretched limb) was passively forced downwards before the knee was passively forced into flexion
(B).
stretching procedures and the initiation of the gait was
less than 30 s. Walking was performed barefoot at the
participant’s freely chosen speed in the plane and filmed
by three camcorders (JVC GR-AX 25; two placed on the
right side and one in the left side of the participants)
sampling with a frequency of 30 Hz. Images were recorded on VHS tape and transferred onto a personal
computer for analysis (Pinnacle, LINX). Recorded images were processed and digitalized using specific software (SIMI MOTION, 6.1). A common LED was set
in the field of view of all cameras to synchronize them.
Fig. 2 shows the setup of the data collection area.
A number of markers (25 mm of diameter) were
placed over the skin and clothes to represent the following landmarks in both sides of the body: (1) anterior superior iliac crest (ASIC), (2) the most prominent
protuberance of the greater trochanter (TROC), (3) lateral femoral epicondyle (KNEE), (4) lateral malleolus
(MALL) and (5) the fifth metatarsal joint (META). Although markers were placed on both sides of the body
only the right side was analysed. The connection between these points defined four rigid body segments,
which are represented in Fig. 3. A three dimensional
movement reconstruction was performed, from which
two separate two dimensional analyses (sagittal and
frontal planes) of the pelvis and of the lower limbs
were performed. Unilateral analysis has been used in
other studies (Kerrigan et al., 2001, 2003; Evans et al.,
2003) and a symmetrical profile between segments in
healthy individuals has been reported (Sadeghi et al.,
2000). The angular convention is shown in Fig. 3.
Ten gait cycles were filmed for each participant in
both experimental conditions (PRE and POS), from
which the first three valid trials (e.g., trials in which all
markers were visible) were selected for further analysis.
Special attention was given to not interfere with the
freely chosen walking velocity. The gait cycle was considered as the period between two consecutive heel contacts
of the right foot, which were normalised to 100% of the
gait cycle. These three cycles were normalised with respect to the gait cycle (first heel contact corresponded
to 0% and the second heel contact corresponded to
100%) and averaged (ensemble averaged) to represent
each individual’s movement pattern. Angular variables
in the sagittal plane were normalised by subtracting
participant’s angles obtained in their normal standing
Fig. 2. Data collection area schematic representation.
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A.L.F. Rodacki et al. / Manual Therapy 14 (2009) 167e172
Fig. 3. Body landmarks and angular displacement conventions. Representation of the anatomical landmarks, body segments, joints and movement
convention. (ASIC e anterior superior iliac crest (L ¼ left; R ¼ right), TROC e the most prominent protuberance of the greater trochanter, KNEE e
lateral femoral epicondyle, MALL e lateral malleolus, and META e the fifth metatarsal joint).
posture. The variables used to describe the gait in the
present study are presented in Table 1.
It was not possible to include a control condition to estimate gait parameter variability. However, a group with
equivalent physical characteristics (aged 65.4 2.9 yearsold, 1.61 0.07 m and 74.3 6.6 kg) participated in the
same gait assessment as a control group in another experiment performed by our laboratory (using a similar
measurement protocol e unpublished data) showed no
significant differences ( p > 0.05) between gait parameters
measured two months apart (within subjects, between
testing days). Variability within subjects (between trials)
also showed similar ( p > 0.05) values for the control
group and the pre-test of the experimental group (see
Table 1, last column). On average, variability of the
selected parameters between groups (control and
PREePOS) was similar to that observed in the experimental conditions. A more detailed analysis revealed
that the variability found in the control group (mean variability ¼ 11.8%) was comparable to that observed in the
experimental group in both conditions (PRE ¼ w12.6%
and POS ¼ 12.3%). A one way ANOVA revealed no
significant differences in terms of variability ( p > 0.05).
Data normality was confirmed using the Kolmogorove
Smirnov test and allowed a number of t-tests for dependent gait variables to determine significant differences
between the two experimental conditions (PRE and
POS). Statistical tests were performed in StatisticaÒ
software package, version 5.5 and the significance level
was set at p < 0.05. Bonferroni’s correction was performed to adjust the significance of coefficient level.
3. Results
The findings of the study are summarized in Table 1.
These show a number of significant differences between
the gait parameters before and after stretching. After
stretching participants were able to achieve a 6.6%
Table 1
Mean gait variables (standard deviation) before (PRE) and after
(POST) stretching exercises, the mean difference and variability within
subjects’ trials (Vwt).
Variable (unit)
PRE
POST
Difference (%) Vwt
CYD (s)
1.10 0.09 1.09 0.09
0.6
STD (%)
62.0 2.1
60.1 2.4
3.1 (*)
SWD (%)
38.0 2.1
39.9 2.4
þ5.1 (*)
DSD (s)
0.18 0.01 0.17 0.005 5.6 (*)
CAD (step/min) 55.3 4.8
55.7 4.3
þ0.7
SLE (m)
0.51 0.07 0.54 0.06
þ5.8 (*)
CLE (m)
0.014 0.01 0.017 0.01 þ16.2
0.96 0.16 1.02 0.15
þ6.6 (*)
SPE (m s1)
1.09 0.3
1.17 0.2
þ6.9
HSV (m s1)
12.9 2.6
15.7 4.6
þ21.9 (*)
PAM ( )
5.0 1.5
6.5 1.7
þ28.4 (*)
PRO ( )
24.4 3.1
25.8 3.7
þ5.7
HAM ( )
49.9 3.3
50.2 5.5
þ0.6
KAM ( )
23.2 3.6
24.9 5.7
þ7.3
AAM ( )
0.02
0.03
0.12
0.06
0.02
0.16
0.49
0.03
0.18
0.12
0.23
0.15
0.05
0.06
Significant differences ( p 0.05) are marked (*). CYD e cycle duration;
STD e stance phase duration; SWD e swing phase duration; DSD e
double support phase duration; CAD e cadence; SLE e step length;
CLE e toe clearance; SPE e gait speed; HSV e heel velocity at foot
strike; PAM e pelvic anterior/posterior tilt amplitude; PRO e pelvic
rotation; HAM e hip flexion/extension amplitude; KAM e knee
flexion/extension amplitude; AAM e ankle dorsiflexion/extension
amplitude; Vwt e Variability within subjects’ trials.
A.L.F. Rodacki et al. / Manual Therapy 14 (2009) 167e172
greater walking velocity achieved by greater step length
with no change in cadence. The increase in step length
was mainly achieved by virtue of greater motion about
the pelvis with increases in both anterior tilt and rotation in the transverse plane.
The gait pattern also showed changes in the temporal
pattern. The increased gait velocity after stretching was
accompanied by a reduction in the stance time, a lower
proportion of time in double support and, a longer
swing duration. These temporal changes are indicative
of improved balance.
4. Discussion
This study aimed to analyse the acute effects of
stretching the hip flexors muscles on walking gait. It
was hypothesized that the transient effect of a single
bout of static stretching exercises would acutely increase joint range of motion and change gait pattern.
These changes are expected to reduce the risk of falls
in elderly (Kerrigan et al., 1998, 2001, 2003; Evans
et al., 2003).
The gait pattern exhibited immediately before
stretching showed dynamic temporal and spatial features similar to those reported in other studies (Murray
et al., 1969; Winter, 1991; Prince et al., 1997; Kerrigan
et al., 1998; Mills and Barrett, 2001). This indicated
that the sample used in the present study was adequate
to represent general healthy elderly population living independently in the community. Aging-related conditions
(e.g., balance problems, osteoarthritis) may produce
changes in gait pattern that could influence our results.
The stretching protocol used in this study was similar
to several others, which have shown significant gains in
range of motion (Murray et al., 1969; Taylor et al.,
1990; Bandy et al., 1997; Prince et al., 1997; Feland
et al., 2001a,b). Although the acute effects of stretching
were not recorded during the experimental session to
determine whether they were still present during the
gait assessment, the short interval imposed (30 s) was
considered sufficient to preserve most exercise effects.
Spernoga et al. (2001) analysed the muscleetendon elastic properties over a much longer period and detected
significant effects were still present 6 min after stretching.
Gait speed has been suggested as the best independent fall-related predictor (Dargent-Molina et al.,
1996). Guimar~
aes and Isaacs (1980) and Woo et al.
(1995) have demonstrated that fallers tend to have
a lower gait velocity in comparison to non-fallers.
Therefore, the greater walking speed found after stretching suggests that these exercises were successful to improve some important functional effects of aging and,
resulted in improved mobility. Thus, stretching exercises
may represent an important strategy to reduce risk of
falls during walking.
171
Walking speed is ultimately determined by step
length and cadence (Zakas et al., 2005). The greater
walking speed found in the present study cannot be explained by cadence, which remained unaltered. Rather
increased step length as a result of increased pelvic rotation and tilting range of motion can be considered as the
key to the greater walking speed after stretching. The
greater range of motion around the pelvis may have
allowed the heel of the swinging leg to strike further in
front of the body (Rose and Gamble, 2006).
Increased pelvic rotation is believed to have an important effect on gait dynamics by flattening the summit
of the centre of mass path, which produces a smoother
displacement of the body (Rose and Gamble, 2006). It
is also described as to cause a more smooth change in
the centre of mass that allows the elderly to attenuate
the impact forces with the ground. Thus, it can be speculated that reducing the impact forces at heel strike may
help to reduce head acceleration during progression and
provide a facilitated stabilization of the visual platform
(Yack and Berger, 1993) and fewer disturbances over the
vestibular apparatus.
Increased double support time in the elderly (Kemoun
et al., 2002) is another well known predictor of falls. The
longer duration of double support can be seen as a necessity to increase stability during progression for the next
step (Viel, 2001). Therefore, smaller double support
time may indicate a better stability during gait, which
may also represent a measure of mobility. This reinforces
the idea that stretching exercises can be an effective way
to improve gait performance in the elderly.
The anterioreposterior heel contact velocity and the
toe clearance have been related to the risk of fall (Winter, 1991). The anterioreposterior heel contact velocity
was similar to that described in other studies
(1.15 m s1 e Sadeghi et al., 2000). This variable is considered to be largely determined by the segmental angular velocities of the thigh, shank and foot of the swinging
leg. The stability of the segmental angular velocities
found in the present study can explain the unchanged
anterioreposterior heel contact velocity and clearance.
5. Conclusion
Stretching exercises resulted in important modifications in gait characteristics that allowed the elderly to
present a movement pattern more similar to that
observed in healthy adults. These results are suggestive
that these exercises constitute an attractive strategy to
improve and/or reduce the negative influence of aging
over a number of functional characteristic related to
fall risk during gait. It is important to have in mind
that stretching exercises are an important component
of physical fitness programs and should be viewed as
one of the factors that influences gait performance.
172
A.L.F. Rodacki et al. / Manual Therapy 14 (2009) 167e172
Studies analyzing the long-term effects of stretching exercises performed under supervision are required to observe whether the transient effects shown in the present
study occur as a result of a systematic training program.
In addition, longitudinal studies relating stretching and
the risk of fall are necessary to confirm experimentally
these suppositions.
Conflicts of interest
Authors have exclusive academic interest in this
manuscript and there are no conflicts of interest in the
present submission.
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