Advances in Physical Education
2013. Vol.3, No.4, 165-168
Published Online November 2013 in SciRes (http://www.scirp.org/journal/ape) http://dx.doi.org/10.4236/ape.2013.34027
Open Access 165
Relationship between Untouched-Toes and Heel Load in
Shigeki Matsuda1, Shinichi Demura2, Kosho Kasuga3, Hiroki Sugiura4
1Gifu Shotoku Gakuen University, Gifu, Japan
2Kanazawa University, Kanazawa, Japan
3Gifu University, Gifu, Japan
4Fukui Prefectural University, Fukui, Japan
Email: firstname.lastname@example.org, email@example.com, firstname.lastname@example.org,
Received September 6th, 2013; revised October 6th, 2013; accepted October 13th, 2013
Copyright © 2013 Shigeki Matsuda et al. This is an open access article distributed under the Creative Commons
Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the
original work is properly cited.
Although the number of children with untouched-toes, which do not touch the floor while standing, is in-
creasing in Japan, the cause of untouched-toes and its effect on the body have been rarely investigated.
This study aims to examine the relationship between untouched-toes and heel load in preschool children.
The subjects were 691 preschool children aged 4 - 6 years (328 boys and 363 girls). The contact surface
area of the soles of the feet was pictured to evaluate the untouched-toes. The posterior foot pressure ratio
in both feet was used to evaluate the heel load. During the entire childhood period, the posterior foot
pressure ratio was significantly larger in children with over two untouched-toes than in children without
untouched-toes for the left foot, and in children with over two untouched-toes than in children without
untouched-toes and with one untouched-toe for the right foot. In addition, this ratio was significantly lar-
ger in children aged 4 years than in children aged 6 years for the left foot, and in children aged 4 years
than in children aged 5 and 6 years for the right foot. In conclusion, children with over two un-
touched-toes tend to have greater heel load than children without untouched-toes.
Keywords: Foot Shape; Untouched-Toes; Foot Pressure Load; Heel Load; Posture; Children
Untouched-toes are the toes that do not touch the floor during
normal standing. Recently, it has been reported that the number
of children with untouched-toes is increasing in Japan (Harada,
2001; Uchida et al., 2001; Matsuda et al., 2009, 2011a). Toes
are an important component in supporting the body and play a
central role in maintaining the body’s balance when standing
and initiating walking movements (Chou et al., 2009). Consid-
ering the role of toes, untouched-toes may have a negative ef-
fect on the body and physical activity. However, the cause of
untouched-toes and its effect on the body have been rarely in-
Physique, physical fitness, balance ability, shoes, heel load,
exercise quantity, and usage frequency of toes have been noted
as factors related to untouched-toes (Harada, 2001; Uchida et
al., 2001). Previous examination of the relationships between
untouched-toes and physique, physical fitness, and balance
ability indicates that there is little relationship between these
three factors (Chou et al., 2009; Matsuda et al., 2010, 2011b).
The relationship between untouched-toes and the quantity of
outdoor exercise has also been examined, and it was reported
that children who belonged to a nursery with more outdoor
exercise had fewer cases with untouched-toes.
Uchida et al. (2002) noted that the heel load, in which the
center of gravity is in a posterior position, is a primary reason
for untouched-toes and Harada (2001) pointed out the same as
one of the reasons for untouched-toes. The magnitude of toe
pressure while standing is affected by the change of the position
of the center of gravity; the more posterior the position is, the
smaller the toe pressure becomes (Fujiwara et al., 1984). Hence,
there may be a relationship between the untouched-toes and
heel load; however, this relationship has been rarely examined.
This study aims to examine the relationship between the un-
touched-toes and heel load in preschool children.
The subjects consisted of 691 preschool children aged 4 - 6
years (328 boys and 363 girls). Table 1 shows the number of
subjects and their physical characteristics. Children were re-
cruited from two kindergartens located in Gifu and Yamagata
cities, Gifu, Japan. The population of Gifu (city) and Yamagata
is approximately 410,000 and 30,000, respectively.
The purpose and procedure of this study were explained to
the subject’s parents in detail and informed consent was ob-
tained before the measurement.
In addition, the consent of the participants for the measure-
ment was obtained at the time of measurement. This experi-
mental protocol was approved by the Ethics Committee on
Human Experimentation of Faculty of Human Science, Kana-
zawa University (2012-05).
S. MATSUDA ET AL.
Number of subjects and their physical characteristics.
Age-4 Age-5 Age-6Total
n 127 101 100 328
Height MEAN 102.8 109.3 115.4 108.6
(cm) SD 4.1 4.7 4.7 6.9
Body mass MEAN 15.7 16.9 19.0 18.8
(kg) SD 1.6 1.8 2.4 2.8
n 145 127 91 363
Height MEAN 102.3 109.3 114.0 107.7
(cm) SD 4.3 4.1 6.3 6.8
Body mass MEAN 15.4 16.7 18.9 18.4
(kg） SD 1.4 2.0 2.4 2.7
Anterior-Posterior Foot Pressure Ratio
The heel load was evaluated by calculating the anterior-pos-
terior foot pressure ratio. This ratio refers to the pressure dis-
tribution between the anterior and posterior parts of the foot. In
the case of the left foot illustrated in Figure 1, the anterior and
posterior ratios are 26% and 74%, respectively. The line divid-
ing the foot into the anterior and posterior parts was formed at
the center of the foot length, which is defined as the distance
from the back of the heel to the front of the longest toe.
A Footview Clinic (Nitta, Japan) was used to measure the
anterior–posterior foot pressure ratio. This measurement device
can calculate the anterior-posterior foot pressure ratio of each
foot using all foot pressures obtained from the area of the foot
that is in contact with the device while the subject is in a stand-
ing position (Figure 1). For the purposes of the present study,
the sampling frequency was 20 Hz.
The anterior-posterior foot pressure ratio was measured us-
ing a previously described method (Matsuda et al., 2012; Ma-
tsuda & Demura, 2013). The subjects stood barefoot on the
Footview Clinic measurement device, with their feet 5 cm apart
and their hands relaxed at the side of the body. Before the
measurement of the anterior-posterior foot pressure ratio, a
stationary picture of the contact area of the sole of the foot was
recorded using the device to obtain their foot length, which was
necessary for analysis. Because of the fact that some children
were unable to touch their toes, a tester pushed the subject’s
toes downward temporarily during the recording of the station-
ary picture. Subsequently, a 10-s measurement was initiated
after the tester confirmed that the child’s posture was stable.
The subjects were instructed to look at a mark located at eye-
level and to remain still as long as possible during the meas-
urement. Each subject was measured three times.
In addition, it is important to note that some young children
could not maintain a stable posture or continuously keep their
eyes on the mark as directed. Such children were excluded from
this study in advance.
Contact Surface Area of the Sole
A pedoscope (Sakamoto, Japan) was used to record the con-
tact surface area of the soles of the subjects’ feet, which was
used for the analysis of untouched-toes. The subjects stood in
the same posture as that for the measurement of the anterior-
Anterior-posterior foot pressure ratio.
posterior foot pressure ratio. After a tester confirmed the sub-
ject’s postural stability, a picture of the contact surface area of
the soles of their feet was recorded. Each subject was sequen-
tially measured five times while standing. Untouched-toes are
defined as the toes that did not emerge in more than four pic-
tures among the five recorded pictures.
The posterior foot pressure ratio was selected as a variable to
evaluate the heel load, and the mean of a 10-s measurement was
used for analysis. It was reported in a previous study that the
second and third trials have high reliability (Matsuda et al.,
2012); therefore, they were used for this analysis.
The number of untouched-toes in both feet was selected as a
variable to evaluate the untouched-toes. Three groups were
established on the basis of the number of untouched-toes: a
group without untouched-toes, a group with one untouched-toe,
and a group with two or more untouched-toes. When a group
with three or more untouched-toes was established, the number
of the subjects in this group was extremely small in comparison
with the other groups. Hence, only the above three groups were
Trial-to-trial reliability was examined using intraclass corre-
lation coefficient (ICC). A two-way analysis of variance
(ANOVA) was used to test the mean differences among the
groups according to different number of untouched-toes and
age (4 - 6 years) in the posterior foot pressure ratio. Owing to
the fact that a significant age difference in the posterior foot
pressure ratio of preschool children has been documented (Ma-
tsuda et al., 2012), the factor of age was set as an independent
factor. If a significant difference was found in the main effect
or interaction, Tukey’s honestly significant difference test was
used for a multiple comparison test. In addition, because there
were no sex differences in the number of untouched-toes and
posterior foot pressure ratio in this study as well as previous
studies (the number of untouched-toes: t = 1.77, p = .08; foot
pressure ratio (right foot): t = −.89, p = .38; (left foot): t = .25, p
= .80) (Matsuda et al., 2009, 2012), the combined data of boys
S. MATSUDA ET AL.
Open Access 167
and girls were used for the above analysis. When a significant
difference was found, the effect size was calculated to examine
the size of the mean difference. The level of statistical signifi-
cance was set at p < .05.
Intraclass correlation coefficients (ICC) for the posterior foot
pressure ratio were .88 and .86 for the left and right feet, re-
spectively. Table 2 shows the results of the two-way ANOVA
and a multiple comparison test for the posterior foot pressure
ratio. Significant differences among the means of the groups
according to different number of untouched-toes and age were
found in both feet. The posterior foot pressure ratio was sig-
nificantly larger in children aged 4 years than in children aged 6
years for the left foot and in children aged 4 years than in chil-
dren aged 5 years and 6 years for the right foot. The effect sizes
were .36 for the left foot, and .22 in children aged between 4
and 5 years and .44 between 4 and 6 years for the right foot.
Regarding the number of individuals with untouched-toes, the
posterior foot pressure ratio was significantly larger in the
group with over two untouched-toes than in the group without
untouched-toes for the left foot and in the group with over two
untouched-toes than in the groups without untouched-toes and
with one untouched-toe. The effect size was .32 for the left foot,
and .39 between the groups with over two untouched-toes and
the group without untouched-toes for the right foot, and .33
between the groups with two untouched-toes and the group
with one untouched-toe for the right foot.
Matsuda et al. (2012) reported that the ICC between the sec-
ond and third trials was high, with a value of .85 for the ante-
rior-posterior foot pressure ratio in preschool children. This was
consistent with the result in our study (.88, .86). Hence, the
reliability of data used in this study is considered to be high.
Although the heel load has been noted as one of the factors
related to the occurrence of untouched-toes (Harada, 2001;
Uchida et al., 2002), the relationship between them has not
been examined. This study evaluated the heel load by calculat-
ing the anterior-posterior foot pressure ratio on the basis of the
line that was established at the center of the foot length and
examined the above relationship. During the entire childhood
period, the posterior foot pressure ratio was significantly larger
in children with over two untouched-toes than in children with-
out untouched-toes and with one untouched-toe. Therefore, it is
considered as one of the reasons of this result that the load of
the toes decreased largely by having over two untouched-toes.
In addition, posture may be related to the present result. Fu-
jiwara et al. (1984) examined the relationship between the ante-
rior-posterior position of the center of gravity and toe pressure
when posture changed from posterior inclination to anterior
inclination. As a result, it was reported that the more anterior a
posture was, the more anterior the position of the center of
gravity was and the larger the toe pressure was. Hence, the
posture of children with over two untouched-toes may be of a
more posterior inclination than that of children without un-
touched-toes. A posterior inclination in the standing posture
induces an increase of muscle activity in the tibialis anterior
muscle, which contains more fast muscle fibers, and is consid-
ered unfit for postural maintenance. In addition, it is considered
that a posterior inclination imposes an inappropriate burden on
other antigravity muscles and has a negative effect on postural
maintenance. The deterioration of posture is noted as a physical
problem of modern young children in Japan (The national net-
work of physical and mental health in Japanese children, 2009).
Untouched-toes may have some relationship with postural in-
clination and the problem regarding postural deterioration. In
future studies, it will be necessary to examine the above prob-
Matsuda & Demura (2013) reported that the posterior foot
pressure ratio decreases with age in young children. The present
result had a tendency similar to the above previous study. Fur-
ther, in studies that examined an age-related change in the ante-
rior-posterior position of the center of gravity, it was reported
that the position moves anteriorly from childhood to adulthood
Results of the two-way ANOVA and a multiple comparison test for the posterior foot pressure ratio.
Age-4 Age-5 Age-6 Two-way ANOVA
U-toes Age Num
n 103 65 104 105 49 74 72 50 69
M 70.8 69.1 73.0 68.4 69.6 71.6 63.7 69.4 69.5F5.317.29 1.97
ratio in the left
foot SD 10.1 12.0 10.4 12.1 11.0 10.3 12.4 11.69.8 p.01*.00* .10
M 68.4 68.6 72.2 66.3 65.5 70.0 61.1 65.4 67.9F9.6410.84 .90
ratio in the right
foot SD 11.7 11.9 10.2 13.2 10.59.8 14.2 12.9 10.0p.00*.00* .46
Noe: U-toe: Untouched-toe, M: Mean, SD: Standard deviation, *p < .05, ES: Effect size. t
S. MATSUDA ET AL.
(Kojima & Takemori, 1980; Usui et al., 1995). Hence, it is
considered that children with over two untouched-toes had a
different tendency from general ones on the development proc-
ess of foot pressure.
In this study, three groups according to the number of un-
touched-toes were formed because of the limit of the number of
subjects. Considering the present results, there is a possibility
that the greater the number of untouched-toes is, the more
marked the tendency of heel load becomes. In addition, it has
been reported that an untouched-toe occurs predominantly in
the fifth toe (Matsuda et al., 2009). If a group having over three
untouched-toes is formed, the effect of the number of un-
touched-toes on the heel load may become notable because it
comprises a group of children with untouched-toes other than
the fifth toe. In future studies, an examination similar to the
present study will be necessary after increasing the number of
subjects and establishing a group with over three untouched-
toes. In addition, the effect of untouched-toes on the heel load
may differ by the part of the untouched-toes. Although the
above effect could not be examined in this study because of the
limit of the number of subjects, it will be necessary to examine
the above effect in future.
Although the relationship between the untouched-toes and
heel load was examined in this study, the movement mass and
type of shoes worn have also been noted as factors related to
the occurrence of untouched-toes (Harada, 2001; Uchida et al.,
2002). To clarify the cause of untouched-toes and its effect on
the body, it will be necessary to examine the above problem.
In conclusion, this study examined the relationship between
the untouched-toes and heel load by studying 691 preschool
children (328 boys and 363 girls) aged 4 - 6 years. Children
with over two untouched-toes have heel loads higher than chil-
dren without untouched-toes. Because the posterior foot pres-
sure ratio decreases with age in young children, the heel load
related to the untouched-toes may not be desirable in terms of
age-related change of foot pressure.
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