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Foot & Ankle International
34(3) 414 –419
© The Author(s) 2013
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DOI: 10.1177/1071100712468562
http://jpc.sagepub.com
Various studies have warned women that wearing high-
heeled shoes (HHS) for a long time can cause musculoskel-
etal changes in the kinematics and kinetics of the lower
extremities and trunk.2,24 Kinematic changes that occur during
walking, such as increased ankle plantarflexion and hyperex-
tension of the metatarsophalangeal joint, are caused by wear-
ing HHS.7,12 In particular, the risk of metatarsalgia caused by
increased plantar pressure at the metatarsal head is increased
with frequent wearing of HHS.1,15,18,25 Kinetic changes also
occur; that is, plantar pressure moves inward,20,22 and the
center of mass moves forward.14
The kinematic and kinetic changes caused by HHS might
induce deformities of the ankle and metatarsophalangeal
joints. However, most studies performed to determine the
musculoskeletal changes induced by HHS have included a
period during which HHS were not worn. Therefore, it is
necessary to undertake a survey to measure the changes that
accompany the actual frequency of wearing HHS.
Previous studies have shown that habitual wearers of
HHS have limited full extension of the knee during walk-
ing,23 increased fatigue of the peroneus muscle,11 and
increased Achilles tendon stiffness.6 However, the long-
term effects of HHS on ankle range of motion (ROM) and
muscle strength remain to be discovered.
The purpose of this study was to compare the ankle
ROM and muscle strength of habitual wearers of HHS and
flat shoes (FS) and to identify characteristics of the ankles
of habitual wearers of HHS. When women wear HHS, their
ankle joints are placed in a more plantarflexed position and
require more stability. We postulate that frequent wearing of
HHS for a long time increases the maximal range of ankle
plantarflexion and inversion and eversion strength.
Methods
Participants
A total of 20 women (age range, 21-29 years) participated
in our study. Participants with dysfunction of the neural or
musculoskeletal system or pain were excluded. All completed
468562FA
IXXX10.1177/1071100712468562Foot & Ankle InternationalKim et al
2013
1Korea University, Seoul, Republic of Korea
2Gachon University of Medicine and Science, Republic of Korea
Corresponding Author:
BumChul Yoon, Korea University, Primary Work, Physical Therapy,
San1, Jeongneung 3-dong, Sungbuk-gu, Seoul, 136-703, Republic of Korea
Email: yoonbc@korea.ac.kr
Changes in Ankle Range of Motion
and Muscle Strength in Habitual
Wearers of High-Heeled Shoes
Yushin Kim, PT, MHSc1, Jong-Min Lim, PT, BSc2, and BumChul Yoon, PT, OT, PhD1
Abstract
Background: Although cross-sectional biomechanical studies have reported that wearing high-heeled shoes can change
the musculoskeletal system of the lower extremities, the long-term effects of wearing such shoes on the ankle remain
unknown. The aim of this study was to reveal changes in ankle range of motion and muscle strength in habitual wearers of
high-heeled shoes and to provide information for clinicians undertaking functional evaluations of the ankles of such patients.
Methods: Habitual wearers of high-heeled shoes (n = 10; age, 23.9 ± 2.7 years) and wearers of flat shoes (n = 10; age,
23.8 ± 2.1 years) were selectively recruited, and the range of motion, maximal voluntary isometric force, and concentric
contraction power of their ankles were measured.
Results: Wearers of high-heeled shoes showed increased ankle range of motion on plantarflexion at 25 degrees and
inversion at 10 degrees compared to flat shoe wearers (P < .05) but decreased dorsiflexion (about 17 degrees) and eversion
(13 degrees; P < .05). Concentric contraction power in ankle eversion was also 2 times higher in wearers of high-heeled
shoes (P < .05).
Conclusions: These subjects had functional deformity of the ankle in a supinated direction and increased eversion power.
Clinical Relevance: We cautiously recommend that habitual wearers of high-heeled shoes (those who walk in such
shoes for more than 5 hours more than 6 times a week) undertake intensive ankle stretching exercises in the direction of
dorsiflexion as well as eversion.
Keywords: ankle, muscle strength, muscle power, physical examination, range of motion, high-heeled shoes
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Kim et al 415
a questionnaire with demographic information, medical
history, and the duration of the period over which they wore
HHS over the preceding 6 months. The participants were
divided into 2 groups based on the criteria outlined in
another study7: an HHS group and a FS group. The HHS
group included 10 women who had worn HHS at least
3 days a week over the past 6 months. The FS group
included 10 women who had worn HHS less than 3 days a
week over the past 6 months. The 2 groups were not sig-
nificantly different in terms of age, height, weight, foot
length, foot width, or total period of wearing HHS.
Furthermore, none had regularly participated in any sports,
strength training, or stretching exercises for the past
6 months. Two subjects were excluded from the study
because they had a low likelihood of wearing HHS over the
past 6 months, although they had often worn HHS for more
than 3 days a week for the previous 1 month. A total of
22 participants were recruited in this study. The Ethics
Committee of Korea University approved this study. All
participants provided their informed consent, and their
identities were coded to protect their privacy.
Measurement of ROM
To examine changes in maximum ankle ROM caused by
HHS, active and passive ROM was measured using an incli-
nometer (Angle Finder AF200M, Dasco Pro Inc, Rockford,
IL). Maximal angular ranges of inversion, eversion, plan-
tarflexion, dorsiflexion with the knee at 90 degrees of flex-
ion (DF-KF), and dorsiflexion with the knee fully extended
(DF-KE) were measured. To measure the ROM of inver-
sion and eversion, the subjects were seated with their feet
off the floor to ensure that the anterior border of the tibia
was vertical and to prevent hip rotation. After fixation, the
angles of the movement of the metatarsal head in the fron-
tal plane were checked. To measure the ROM of plan-
tarflexion and dorsiflexion, subjects were asked to place
their ankles over the edge of a table while lying in a supine
position. Then, the maximal movement angle of the fifth
metatarsal bone was used to determine the ankle ROM on
the sagittal plane relative to the vertical. To examine the
effects on the soleus and gastrocnemius muscles, dorsiflex-
ion was checked with the knee at 90 degrees flexion and
fully extended. To measure DF-KF, the subject lay in a
supine position with hip and knee at 90 degrees flexion
with the tibia fixed in place horizontally. The angle of ankle
maximal dorsiflexion from the vertical was then measured.
All measurements were taken 3 times.
Measurement of Muscle Strength
Ankle muscle strength was measured using a multimodal
dynamometer (Primus RS, BTE Technologies Inc., Baltimore,
MD). To measure the maximal voluntary isometric force
(MVIF) in 4 directions (inversion, eversion, plantarflexion,
and dorsiflexion) of both ankles, an axis of dynamometer
was fixed in place. Concentric contraction power at the 25%
and 75% MVIF levels was measured for both ankles in the
same MVIF posture, and subjects were instructed to use
maximal effort to ensure concentrated speed as well as
force. Measurement postures were determined in the plan-
tarflexion, dorsiflexion, inversion, and eversion directions.
To measure dorsiflexion and plantarflexion, the subject lay in
a supine position with the pelvis and tibia fixed in position
up on a table (see Figure 1). Strength of ankle eversion and
inversion was then measured in a sitting position by fixing
the thigh in place to prevent movement of the hip joint (see
Figure 2). All measurements were repeated 3 times.
Statistical Analysis
Our purpose was to compare the ROM, MVIF, and concen-
tric contraction power at 25% and 75% MVIF between the
HHS and FS groups. We used an independent t test to com-
pare demographic characteristics and the period of wearing
HHS between groups. Levene’s test for equality of vari-
ances was used in relation to the underlying assumptions of
parametric statistics. The reproducibility of trials was tested
by intraclass correlation coefficients. Data from the
2 groups included the average of 3 trials for the left and
right ankles and were compared by repeated measures
analysis of variance in SPSS 12.0. Statistical significance
was accepted for P values less than .05.
Figure 1. The position used for the ankle strength
measurements (maximal voluntary isometric force and
concentric contraction power) of dorsiflexion and plantarflexion.
The axis of a multimodal dynamometer was located at the lateral
malleolus, and the distal part of the tibia was fixed in position.
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416 Foot & Ankle International 34(3)
Results
No significant differences between the HHS and FS groups
in mean age, height, weight, foot length, foot width, or
period of wearing HHS were observed. However, a signifi-
cant difference was observed in the frequency of wearing
HHS and walking while wearing HHS for a week (Table 1).
Moreover, the maximum ROM differed between the HHS
and FS groups. ROM measures were dichotomized as
active and passive ROM. Measurement of active ROM was
chiefly performed in the clinical field because most of the
tasks performed during daily life require active ROM.4
Passive ROM was measured to confirm the passive visco-
elastic properties of the involved muscles, pain, and neural
inhibition.27
Ankle ROM
The maximum active and passive ROM of plantarflexion
and inversion was approximately 25 degrees and 10
degrees higher, respectively, in the HHS group compared
with the FS group (P < .05). In contrast, maximum DF-KE
and eversion were 16 degrees and 9 to 4 degrees higher in
the FS group compared with the HHS group (P < .05). In
DF-KF, only passive ROM was significantly decreased by
6 degrees in the HHS group (P < .05). The active and pas-
sive ROM values are shown in Table 2. Based on 3 ROM
measurements, the minimum intraclass correlation coeffi-
cient value was 0.886.
Ankle Strength
Ankle strength was assessed on the basis of MVIF and
concentric contraction power. The MVIF in eversion was
higher in the HHS group than the FS group; however, there
was no statistical difference between the 2 groups in all
directions (P > .05). The concentric contraction power was
measured at 25% and 75% of MVIF in both the FS and
HHS groups. Except for eversion, no significant difference
in concentric power was observed between the 2 groups.
The HHS group had higher eversion power (range, around
2-3 W) than the FS group (P < .05) at both 25% and 75%
of MVIF. The mean values of ankle muscle strength are
shown in Table 3. Based on 3 trials, the intraclass correla-
tion coefficient for MVIF, with concentric contraction
power at 25% and 75% of MVIF, was over 0.871.
Discussion
To understand clinically the musculoskeletal effects of
wearing HHS, orthopaedic examination of habitual high-
heeled shoe wearers is important. The purpose of this study
was to compare ankle ROM and muscle strength between
habitual wearers of HHS and FS. We found that the physi-
cal ability of the ankles of wearers of HHS was signifi-
cantly different from that of the wearers of FS in terms of
kinematics and kinetics.
Regarding kinematic changes, the maximum ROM of
plantarflexion and inversion was higher in the HHS group
compared with the FS group; however, DF-KE and eversion
were lower. This indicates that the range of ankle joint
mobility in the HHS group was shifted to a supinated posi-
tion. These results lead to the speculation that tissues around
the ankle become lax on the anterolateral side and stiff on
the posteromedial side—that is, an elongated anterior talo-
fibular ligament and a stiff deltoid ligament and Achilles
tendon. We considered that changes in ankle ROM related
to the supinated position were caused by kinematic charac-
teristics during walking with HHS. Other studies have
reported increased maximum peak angles of plantarflexion
and inversion in the ankle during walking with HHS; how-
ever, their experimental data compared maximum peak
angles of the ankle in HHS and FS and were inconsis-
tent.7,17,29,30 Thus, it is possible that the gait pattern when
wearing HHS affects supinated deformation of the ankle
ROM in wearers of HHS.
In particular, the ankle plantarflexed position in HHS
would reduce the length of the gastrocnemius muscle relative
to the other calf muscles. We dichotomized dorsiflexion
ROM in the knee at full extension and at 90 degrees of flex-
ion because examinations of ankle dorsiflexion at different
knee positions are useful for discriminating posterior ankle
structure shortening between monoarticular and biarticular
Figure 2. The position used for the ankle strength
measurements (maximal voluntary isometric force and
concentric contraction power and concentric contraction
power) of inversion and eversion. The lever arm of a multimodal
dynamometer and the body of the femur were lined up, and the
distal part of the femur was fixed in position.
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Kim et al 417
Table 2. Comparisons of Active and Passive Range of Motion, in Degreesa
Active Passive
Direction FS HHS FS HHS
DF-KE 16.1 ± 9.4b0.1 ± 8.4 21.9 ± 9.6b4.0 ± 9.5
DF-KF 26.4 ± 6.2 24.4 ± 6.7 35.4 ± 6.3b29.5 ± 8.3
Plantarflexion 80.7 ± 16.9 100.8 ± 13.4c88.6 ± 22.7 106.8 ± 16.2c
Inversion 42.7 ± 9.8 53.0 ± 16.3c50.0 ± 8.9 60.5 ± 17.2c
Eversion 32.9 ± 12.9b21.2 ± 10.5 38.9 ± 13.4b24.6 ± 8.9
Abbreviations: FS, flat shoes group; HHS, high-heeled shoes group; DF-KE, dorsiflexion in knee full extension; DF-KF, dorsiflexion in knee 90 degrees of
flexion.
aMean ± standard deviation.
bAngle of maximum range of motion is significantly higher than HHS (P < .05).
cAngle of maximum range of motion is significantly higher than FS (P < .05).
Table 3. Comparisons of Ankle Isometric Force and Concentric Powera
Isometric Force (N)
Concentric Power
at 25% Load Level (W)
Concentric Power
at 75% Load Level (W)
Direction FS HHS FS HHS FS HHS
Dorsiflexion 28.4 ± 6.2 25.1 ± 8.3 5.6 ± 3.7 5.1 ± 2.1 9.2 ± 3.6 10.0 ± 4.4
Plantarflexion 27.1 ± 9.7 24.0 ± 9.3 6.4 ± 3.6 6.1 ± 3.7 13.5 ± 7.4 11.4 ± 9.5
Inversion 22.9 ± 11.2 26.6 ± 15.8 5.9 ± 3.3 7.7 ± 4.8 11.1 ± 8.8 13.7 ± 10.0
Eversion 13.8 ± 7.8 19.2 ± 9.2 2.9 ± 2.7 5.0 ± 4.0b5.1 ± 3.4 8.1 ± 5.2b
Abbreviations: FS, flat shoes group; HHS, high-heeled shoes group.
aMean ± standard deviation.
bConcentric power is significantly higher than HHS (P < .05).
Table 1. Anthropometric Characteristics of Participantsa
FS, n = 10 HHS, n = 10 t P
Mean age, y 23.8 ± 2.1 23.9 ± 2.7 –0.092 .928
Height, cm 165.0 ± 4.8 162.8 ± 4.6 1.071 .298
Weight, kg 54.2 ± 4.6 54.0 ± 4.8 0.096 .925
Foot length, mm 237.2 ± 11.5 239.7 ± 5.4 –0.592 .562
Foot width, mm 8.6 ± 0.6 8.8 ± 0.3 –0.578 .576
Total wearing period, yb3.8 ± 1.7 5.6 ± 1.2 –0.438 .667
Wearings for a week, nc1.1 ± 0.8 5.5 ± 1.3 –7.782 <.001
Wearing periods for a week, hd2.3 ± 1.7 4.6 ± 0.9 –4.347 <.001
Preferred heel height 5.6 ± 1.4 7.6 ± 2.3 –1.993 .062
Abbreviations: FS, flat shoes group; HHS, high-heeled shoes group.
aMean ± standard deviation.
bWearing period of the high-heeled shoes in participants’ lifetime.
cFrequency of wearing the high-heeled shoes for a week.
dWalking period with wearing the shoes per week.
muscles.19 The maximum ROM of DF-KE was about
16 degrees lower in the HHS group compared with the FS
group, whereas DF-KF was not different or was only slightly
different. This indicates that the gastrocnemius muscle fascia
of the HHS group was shorter than the other ankle structures,
such as the soleus muscle and the posterior joint capsule.
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418 Foot & Ankle International 34(3)
The supinated metamorphosis of the ankle in the HHS
group would lead to functional changes in the musculoskel-
etal system; that is, it would disturb efficient shock absorp-
tion of the deltoid and spring ligament7 and increase the risk
of anterior talofibular ligament sprains.21 In addition, lim-
ited ankle dorsiflexion ROM is associated with poor calf
muscle pump function in limbs with chronic venous insuf-
ficiency19 and could contribute to increased gait deviations,
such as decreased step length and walking speed.8 Thus, we
were able to establish that kinematic changes induced by
wearing HHS have a negative influence on the ankle and
that regular ankle stretching in the direction of dorsiflexion,
with the knee extended, and at eversion is essential for
habitual wearers of HHS.
We also found that the HHS group had a significantly
higher concentric contraction power in eversion than the FS
group. Muscle power is the ability of a muscle to produce
force rapidly, is defined as the product of force and time,
and is generated during activities that involve movement.28
We first considered that increased muscle power of eversion
would be induced as an adaption to mediolateral instability
induced by a narrow heel. A previous study also reported
that peroneus muscle activity was increased during walking
with heeled shoes owing to a decreased base of support.30
The enhanced eversion power observed in the HHS group
indicates that ankle instability while wearing HHS can
induce a rapidly generated force affecting the peroneus
muscle and that this is important for preventing ankle
sprains.3,5,16 Second, increased eversion power results from
shifting the center of the body mass laterally when women
walk in HHS.11 That is, the medial longitudinal arch and the
spring ligament complex are key structures for shock
absorption generally.26,30 During the stance phase of walk-
ing wearing HHS, however, the center of gravity shifts lat-
erally with increased hip adduction. The external moment
arm of the ankle axis is increased, and the peroneus muscle
requires more power to maintain balance. This process
emphasizes the role of the peroneus muscle as a shock
absorber. Thus, the increased mediolateral instability and
the lateral transfer of the center of gravity during walking in
HHS act as the main effectors increasing the concentric
power of ankle eversion.
Our results show that habitual wearers of HHS have to
increase dorsiflexion and eversion ROM. Thus far, several
studies have reported the effect of stretching exercises on
the calf muscles to increase the dorsiflexion ROM of nor-
mal subjects.9,10,13,31,32 Of these, a passive stretching exer-
cise with programmed long, frequent stretching times (more
than 150 seconds per day, 5 days per week for 6 to 8 weeks)
with a short resting period had a positive effect on increas-
ing ankle ROM.9,10,13 For habitual wearers of HHS, more
intensive stretching exercises are necessary. In addition, our
study suggests that the stretching exercises should be per-
formed in the direction of not only dorsiflexion but also
eversion. Further studies are required to determine whether
the intensity of the outlined stretching program is effective
for habitual wearers of HHS.
In conclusion, this study found that habitual wearers of
HHS have a significantly altered musculoskeletal system in
the ankle, resulting in supinated ROM and increased ever-
sion power. Moreover, ankle adaptations to maintain bal-
ance from a narrow base of support when wearing HHS
evoke kinematic and kinetic changes. However, the ankle
adaptations are known to have a clinically negative impact
by increasing the risk of inversion sprains,21 poor calf mus-
cle pumping,19 and unstable gait.8 Therefore, we recom-
mend that clinicians check the frequency of a patient’s
wearing of HHS and that they understand the physical char-
acteristics of the ankles of habitual wearers of HHS when
undertaking functional evaluations.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with
respect to the research, authorship, and/or publication of this
article.
Funding
The author(s) received no financial support for the research,
authorship, and/or publication of this article.
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