Advances in Physical Education
2012. Vol.2, No.2, 44-48
Published Online May 2012 in SciRes (http://www.SciRP.org/journal/ape) http://dx.doi.org/10.4236/ape.2012.22008
44
Reliability and Sex Differences in the Foot Pressure Load Balance
Test and Its Relationship to Physical Characteristics in Preschool
Children
Shigeki Matsuda1, Shinichi Demura2, Kosho Kasuga3, Hiroki Sugiura2
1Gifu Shotoku Gakuen Un i versity, Gifu, Japan
2Graduate School of Natural Science & Technology, Kanazawa Uni ver sity, Kanazawa, Japan
3Gifu University, Gifu, Japan
Received April 1st, 2012; revised May 4th, 2012; accepted May 15th, 2012
This study aimed to examine the trial-to-trial reliability and sex differences in a foot pressure load balance
test and its relationship to physical characteristics in 396 preschool children (201 boys and 195 girls). The
subjects were asked to maintain an upright standing posture for 10 seconds three times on the Footview
Clinic, an instrument designed to calculate the right-left and anterior-posterior ratios of foot pressure load.
The ratios of the left and anterior foot pressure loads in right and left feet were selected as variables. In-
tra-class correlation coefficients between the second and third trials in all variables were high (intra-class
correlation coefficients = 0.70 - 0.90). The above variables showed insignificant sex differences and little
relationships with physique. When measuring foot pressure load balance, it is desirable to use a mean of
the second and third trials as a representative.
Keywords: Foot Pressure Load Balance; Preschool Children; Sex Difference; Reliability
Introduction
Toes play an important role in propelling the body forward
when walking and running and in maintaining posture while
standing (Hughes et al., 1990; Kulthanan et al., 2004; Chou et
al., 2009; Tanaka et al., 1996; Hutton & Dhanendran, 1979). In
the case of children’s toes, problems related to toe deformities
such as curly and overlapping toes are sometimes found (Asir-
vatham, 2001; Wenger & Leach, 1986). It was recently reported
that many young children in Japan have an “untouched-toe”,
referring to the case in which a toe does not touch the floor
while standing (Matsuda et al., 2009, 2011; Harada, 2001).
Harada (2001) reported that the rate of occurrence of untouched
toes in children was about 5% - 10 % in 1980, but the ratio
increased rapidly to about 50% in 2000. Although a child with
untouched-toes does not require surgery as with the case of curly
toes and other foot disorders (Asirvatham, 2001; Wenger &
Leach, 1986), a great deal of attention has been paid to this
condition because the rate of occurrence has increased so markedly
(Matsuda et al., 2009, 2011; Harada, 2001). A decrease in toe
use frequency along with decreases in movement mass, type of
shoes worn, and heel load etc. have been noted as factors re-
lated to the occurrence of untouched-toes (Harada, 2001), the
relationships between the above factors and the occurrence of
untouched-toes have not been examined.Above all else, because
heel load is considered to play a role in posture deterioration, it
is necessary to clarify the relationship between the occurrence
of untouched-toes and heel load. When evaluating heel load, it
is necessary to evaluate the anterior-posterior balance of foot
pressure load after dividing the foot pressure load into the ante-
ri or and posterior parts. However, because a method to adequa t e l y
evaluate the anterior-posterior balance of foot pressure load has
not been established, the relationship between the untouched-
toes and heel load has not been examined.
On the other hand, human’s body has functional asymmetries
such as a dominant hand, a dominant leg, and a dominant eye.
Previc (1991) stated that many people depend on the left side of
their bodies for posture maintenance because the left otolith
function, which is an organization related to balance sense in
inner ear, is superior to the right one. Because there is a large
possibility that there is also some asymmetry in foot pressure
load balance, the examination of the asymmetry is needed.
Recently , a device (The Foot view Clinic, Nitta, Japa n) designed
to measure the right-left and anterior-posterior balances of foot
pressure load was developed, thereby allowing foot pressure
load balance to be determined easily. We can examine the rela-
tionship between untouched-toes, anterior-posterior balance of
the foot pressure load and the asymmetry of the foot pressure
load through the use of this device. However, the human body
always sways while standing, measured values will also vary.
In addition, because young children are not always able to fully
understand the measurement procedure, many trials are needed
to get stable measured values. It is necessary to examine the
reliability of the measured values calculated by the above device.
Because the contact area of the soles of the feet is the area
supporting the body weight, foot pressure and sole shape are
affected by the body weight. The amount of pressure exerted on
the feet is greater for obese people than for people of a normal
body weight (Hills et al., 2001) and, accordingly, sole shape (e.g.
the prevalence of flat-footedness) differs between these two
groups. Hence, variables related to foot pressure load balance
may be affected by physique. If this is true, it will be nec essary

S. MATSUDA ET AL.
to examine whether the effect should be taken into consideration.
On the other hand, because foot pressure load balance in
young children has not been measured, possible sex differences
in their relevant variable have not been determined. Matsuda et
al., (2007) reported that the contact area and the middle part of
the foot width of preschool children are larger in boys than in
girls. Hence, sex differences may be found also in the foot pres-
sure load variables. This study aims to examine the trial-to-trial
reliability and sex difference in foot pressure load balance vari-
ables and their relationships to physique in preschool children.
Methods
Subjects
The subjects consisted of 396 preschool children aged 3 to 6
years (201 boys and 195 girls) who commute to two kindergar-
tens (Table 1).
The purpose and procedure of this study were explained to
the parents of participants in detail and informed consent was
obtained before the measurement. In addition, the consent of
the participants for the measurement was obtained at the time of
measurement. This experimental protocol was approved by the
Ethics Committee (Kanazawa University Health & Science
Ethics Committee).
Measurement Device
The Footview Clinic (Nitta, Japan) was used to measure the
foot pressure load balance. This device is designed to calculate
the right-left and anterior-posterior balances of foot pressure
load from the area of the foot that is contact with the device
during standing (Figure 1). The sampling frequency was 20 Hz.
The right-left and the anterior-posterior balances refer to the
proportion of pressure distribution between the left and right
foot (In a case of Figure 1: left foot 55 and right foot 45) and
the proportion of pressure distribution between the anterior and
posterior parts of foot (In a case of left foot in Figure 1: ante-
rior part 26 and posterior part 74), respectively. The line divid-
ing the foot into anterior and posterior parts was set at the cen-
ter of the foot length, which was defined as the distance from
the back of the heel to the front of the longest toe. The foot
length was calculated using a personal computer.
Measurement Procedure
The subjects stood barefoot on the measurement device with
Table 1.
Physical characteristics of subjects.
Age-3Age-4 Age-5 Age-6Total
n 16 58 55 72 201
Height MEAN 98.7 102.6 109.5 114.8109.8
(cm) SD 3.9 4.0 5.0 4.7 6.3
Body mass MEAN 15.8 16.8 19.0 20.519.2
Boys
(kg) SD 1.9 1.7 2.5 2.4 2.6
n 10 70 57 58 195
Height MEAN 98.0 103.3 108.2 115.2106.6
(cm) SD 3.0 3.6 4.8 4.2 7.3
Body mass MEAN 15.8 17.0 18.6 21.118.0
Girls
(kg) SD 1.6 1.8 2.6 2.3 2.8
Figure 1 shows the right- left and anterior-posterior balances of foot press ure load.
In case of Figure 1, the ratios of left foot pressure load, the anterior part of left
foot pressure load , and the anterior p art of the right foot pressure load are 55, 26,
and 37, respectively.
Figure 1.
Balance of the foot pressure load.
their feet 5 cm apart and their hands relaxed at the side of the
body. They were instructed to look at a mark located at eye-level
and to stabilize their posture for as long as possible during the
measurement. After confirming posture stability, a ten second
measurement was started. Each subject was measured three
times. Here it is important to note that some young children
were unable to maintain stable posture or were not able to con-
tinuously keep their eyes on the mark as directed. Such children
were excluded from this study in advance.
Evaluation Vari ables
It will be necessary to examine the relationship between the
anterior-posterior balance of the foot pressure load and untou-
ched-toes and the asymmetry in the foot pressure load in pre-
school children. Hence, the ratios of left foot pressure load (left
foot load), the anterior part of left foot pressure load (left-anterior
load), and the anterior part of the right foot pressure load (right-
anterior load) were selected as foot pressure load balance vari-
ables. Each of these variables refer to the ratios of the left foot
with respect to the right foot when consi dering the pressure loa d i n
both feet, the anterior part of the left foot in its pressure load,
and anterior part of the right foot in its pressure load, respect-
tively. Incidentally, the ratios of the right foot pressure load and
the posterior part of the left foot pressure load were defined as
the difference of the left foot load and 100 and the difference of
the left-anterior load and 100, respectively (Figure 1). The
means for a 10 second measurement in all variables were used
for analysis. The measurement device is also able to calculate
the total sway length. Because this variable adversely affects
the trial-to-trial reliability of the foot pressure load balance
variables, it was selected as a variable.
Statistical Analysis
Basic statistics of all variables in each trial were calculated.
To test mean differences between trials, one-way analysis of the

S. MATSUDA ET AL.
46
variance was used. If a significant difference was found, Tukey’s
HSD test was used for a multiple comparison test. Trial-to-trial
reliability was examined using intra-class correlation coeffi-
cients (ICC). ICC is widely used when examining the stability
of measured values between trials (Shrout & Fleiss, 1979; Landis
& Koch, 197 7). After selectin g a representat ive value, an un paired
t-test was used to test for a sex difference with respect to the
foot pressure load balance variables. Peason’s correlations were
calculated to examine relationships between the foot pressure
load balance variables and height, body mass, and BMI.BMI
(body weight/height2) was calculated by reference to Cole
(2000).The level of statistical significance was set at p < 0.05.
Results
Table 2 shows basic statistics, test results of mean differ-
ences between trials, and ICC for each variable. After testing
mean differences between trials,there were no significant dif-
ferences between the mean values for all trials for boys. How-
ever, the mean for girls was significantly higher in the first trial
than in the third trial for the left-anterior and right-anterior
loads. There was a significant difference in the mean of total
sway length between trials for both boys and girls in that it was
significantly higher in the first trial than in the second trial for
boys and significantly higher in the first trial than in both the
second and third trials for girls. After calculating ICCs to ex-
amine trial-to-trial reliability, ICC of the second and third trials
was the highest in all foot pressure load balance variables. ICCs
for boys and girls were 0.70 and 0.73 in left foot load, 0.90 and
0.87 in left-anterior load, and 0.86 and 0.85 in right-anterior
load, respectively.
The means of the second and third trials were used as repre-
sentative values of the foot pressure load balance variables in
subsequent analyses. After testing sex differences with respect
to the foot pressure load balance variables, there were no sig-
nificant sex differences in the foot pressure load balance vari-
ables (Table 3). When examining relationships between the
foot pressure load balance variables and physique, significant
correlations were found between left-anterior and/or right-anterior
loads a nd height and b ody mass in boy s, and between le ft-anterio r
load and BMI in girls, but their values were low (Table 4).
Discussion
The ratios of the left foot pressure load, and the pressure
loads of the anterior parts of the left and right feet were selected
as variables for the foot pressure load balance in this study.
Because the human body always sways while standing, meas-
ured values also vary. Foot pressure load balance variables
trial-to-trial reliability has not been examined. In addition, be-
cause some of the young children had trouble understanding the
measurement method, multiple trials were needed in order to
obtain stable measured values. Reliability between the second
and third trials was the highest for all foot pressure load balance
variables and their ICCs were over 0.7. Jackson et al., (1980)
judged that reliability is good when ICC is over 0.7. In addition,
significant differences between the first and third trials were
found in two foot pressure load balance variables in girls.
Namely, it was suggested that stable measured values could be
obtained after the second trial. Hence, foot pressure load bal-
ance in young children is required to measure more than two
trials and when measuring three trials, it may be adequate to use
the mean of the second and third trials as a representative value.
Based on the present results, the mean of the second and third
trials were used in this study. The total sway length showed
insignificant difference between the second and third trials but
was significantly longer in the first trial than in the second and
third trials (Table 3). Namely, it is inferred that bodily posture
is more unstable in the first trial than in trials after the second
one. Because this was the first time the subjects had their foot
pressure load balance measured, they may have been uneasy
and inexperienced at the first trial. It is inferred that they gradu-
ally got used to the measurement and could maintain a stable
posture after the second trial.
Three trials were performed in consideration of the effects of
fatigue. Hence, trial-to-trial reliability after the fourth trial is
unclear for the foot pressure load balance variables. Although
the subject’s unease and inexperience may decrease after the
fourth trial, there is a possibility that fatigue and practice effects
could affect measurement results.
On the other hand, in preschool children, the figure of the
contact area of the feet differed between boys and girls (Ma-
tsuda et al., 2007). Sex difference may be found also in the foot
pressure load balance variables. Hence, it was necessary to
confirm their difference. The present results did not show sex
differences in all foot pressure load balance variables. Hence,
data can be analyzed without having to distinguish between
which measurements came from of boys and girls.
It was reported that obese people experience greater foot
pressure and are more likely to have flat feet than people of a
normal weight (Hills et al., 2001; Riddiford-Harland et al.,
Table 2.
Basic statistics, test results of mean differences between trials, and ICC for each variable.
1st trial 2nd trial 3rd trial One-way ANOVAICC
M SD M SD M SD F p
Tukey’s
HSD 1-2 trials 1-3 trials2-3 trials
Boys Left foot load 50.0 6.8 50.6 7.3 50.6 7.1 1.20 0.30 0.62 0.60 0.70
Left-anterior load 31.3 10.6 30.8 11.0 30.7 11.6 1.02 0.36 0.85 0.81 0.90
Right-anterior load 33.9 11.2 33.7 11.7 33.5 12.5 0.32 0.70 0.85 0.76 0.86
Total sway length 14.7 4.8 13.9 4.8 14.3 5.6 3.81 0.03 1 > 2 0.66 0.59 0. 63
Girls Left foot load 51.5 6.2 51.6 5.8 51.9 6.6 0.48 0.62 0.67 0.57 0.73
Left-anterior load 31.7 11.0 30.9 11.0 30.5 10.9 3.48 0.04 1 > 3 0.81 0.80 0.87
Right-anterior load 35.3 11.7 34.4 12.7 33.8 12.0 4.74 0.01 1 > 3 0.85 0.78 0.85
Total sway length 13.2 5.0 12.5 5.1 12.3 5.8 5.88 0.00 1 > 2, 3 0.74 0.76 0.79

S. MATSUDA ET AL.
Table 3.
Sex differences in foot pressure load balance va riables.
Boys Girls t p
MEAN 50.6 51.7 –1.76 0.08
Left foot load SD 6.7 5.8
MEAN 30.7 30.7 0.06 0.42
Left-anterior load SD 11.0 10.6
MEAN 33.6 34.1 –0.42 0.73
Right-anterior load SD 11.6 11.9
Table 4.
Relationships be tween foot pre ssure load bala nce variables and p hysique.
Boys Girls
Height Body
mass BMI Height Body mass BMI
r –0.09 –0.10–0.04 0.07 0.02–0.07
Left foot
load p 0.21 0.14 0.54 0.35 0.730.32
r –0.16* –0.130.03 0.00 0.070.15*
Left-anterior
load p 0.02 0.08 0.71 0.96 0.330.03
r –0.17* –0.17*–0.05 0.07 0.120.12
Right-anterior
load p 0.01 0.01 0.45 0.32 0.090.11
Note: *p < 0.05.
2010; Mickle et al., 2006). Because body mass or BMI affects
foot pressure load and the shape of the contact area of the foot
sole, it was hypothesized that foot pressure load balance vari-
ables are affected by physique. Although height, body mass,
and BMI showed significant correlations with foot pressure
load balance variables, their relationships were very low. Hence,
it was judged that physique affects little foot pressure load balance.
The number of young children with an untouched-toe has in-
creased in Japan (Matsuda et al., 2009, 2011) and heel load has
been cited as one of the many factors related to it. If the rela-
tionship between the untouched-toe and heel load is clarified, a
better understanding of why its occurrence has recently in-
creased may be obtained.
Humans have some functional asymmetries (Dittmar, 2002)
with the lower limbs being divided into a supported-leg (which
supports the body) and a functional-leg which has superior
manipulation abilities (Peters, 1988). However, the upper limbs
as compared with the lower limbs have clear asymmetry. In
addition, the functional asymmetry of the lower limbs has not
been thoroughly studied. Because of the present results, it now
possible to examine the asymmetry of the foot pressure load
balance. It will be needed to examine the age difference of the
foot pressure load balance variables, the relationships between
the variables and posture, the shape of the contact area of the
foot sole, and so on in the future.
Conclusion
This study examined the trial-to-trial reliability, sex differ-
ence in the foot pressure load balance variables and their rela-
tionship with physique in preschool children aged 3 to 6 years
(201 boys and 195 girls). Significant differences between the
second and third trials were not found in any of the foot pres-
sure load balance variables and their intra-class correlation co-
efficients were high (intra-class correlation coefficients = 0.70 -
0.90). The above variables showed no sex differences and little
relationship with physique. The measurement of the foot pres-
sure load balance is desirable to conduct more than two trials
and it may be adequate to use a mean of the second and third
trials as a representative value when performing three trials.
REFERENCES
Asirvatham, R. (2001). Foot problems seen in children. Practitioner,
245, 756-759.
Chou, S. W., Cheng, H. Y., Chen, J. H., Ju, Y. Y., Lin, Y. C., & Wong,
M. K. (2009). The role of the great toe in balance performance. Jour-
nal of Orthopaedic Re se a rc h, 27, 549-554. doi:10.1002/jor.20661
Cole, T. J., Bellizzi, M. C., Flegal, K. M., & Dietz, W. H. (2000). Es-
tablishing a standard definition for child overweight and obesity
worldwide: International survey. British Medical Journal, 320, 1240-
1243. doi:10.1136/bmj.320.7244.1240
Dittmar, M. (2002). Functional and postural lateral preferences in hu-
mans: Interrelations and life-span age differences. Human Biology,
74, 569-585. doi:10.1353/hub.2002.0040
Harada, S. (2001). A study on physical structures of preschool chil-
dren’s feet compared between 1980 and 2000. The Japanese society
for Medical Study of Foot We ar , 15 , 14-18.
Hills, A. P., Hennig, E. M., McDonald , M., & Bar-Or, O. (2001). Plan-
tar pressure differences between obese and non-obese adults: A bio-
mechanical analysis. International Journal of Obesity, 25, 1674-1679.
doi:10.1038/sj.ijo.0801785
Hughes, J., Clark, P., & Klenerman, L. (1990). The importance of the
toes in walking. The Journal of Bone and Join t S urgery, 72, 245-255.
Hutton, W. C., & Dhanendran, M. (1979). A study of the distribution of
load under the normal foot during walking. International Orthopae-
dics, 3, 153-157.
Jackson, A., Jackson, A. S., & Bell, J. (1980). A comparison of alpha
and the intraclass reliability coefficients. Research Quarterly for Ex-
ercise & Sport, 51, 568-571.
Kulthanan, T., Techakampuch, S., & Bed, N. D. (2004). A study of
footprints in athletes and non-athletic people. Journal of the Medical
Association of Thailand, 87, 788-793.
Landis, J. R., & Koch, G. G. (1977). The measurement of observer
agreement for categorical data. Biometrics, 33 , 159-174.
doi:10.2307/2529310
Matsuda, S., Demura, S., &Kasuga, K. (2011). Changes in floating-toes
one year later in preschool c hild ren based on longitudina l d at a . Japan
journal of human growth and development research, 51, 19-26.
Matsuda, S., Demura, S., Miyaguchi, K., Kasuga, K., Kitabayashi, T.,
Aoki, H., &Yamamoto, Y. (2009). Sex, age, and right and left dif-
ferences of floating-toe and its relationship with physique in pre-
school children. The Journal of Education and Health Science, 54,
198-205.
Matsuda, S., Demura, S., Kasuga, K., Aoki H., & Ikemoto Y. (2007).
Gender and age differences in the contact area of the soles of the feet
and its relationship with physique in preschool children. The Journal
of Education and Health Sci en c e , 53, 184-193.
Mickle, K. J., Steele, J. R., & Munro, B. J. (2006). The feet of over-
weight and obese young children: Are they flat or fat? Obesity, 14,
1949-1953. doi:10.1038/oby.2006.227
Peters, M. (1988). Footedness: Asymmetries in foot preference and
skill and neuropsychological assessment of foot movement. Psycho-
logical Bulletin, 103, 179-192. doi:10.1037/0033-2909.103.2.179
Previc, F. H. (1991). A general theory concerning the prenatal origins
of cerebral lateralization in humans. Psychological Review, 98, 299-
334. doi:10.1037/0033-295X.98.3.299
Riddiford-Harland, D. L., Steele, J. R., & Baur, L. A. (2010). Are the
feet of obese children fat or flat? Revisiting the debate. International
Journal of Obesity, 3 5 , 115-120. doi:10.1038/ijo.2010.119
Shrout, P. E., & Fleiss, J. L. (1979). Intraclass correlations: Uses in as-

S. MATSUDA ET AL.
sessing rater reliability. Psychologi cal Bulletin, 86, 420-428.
doi:10.1037/0033-2909.86.2.420
Tanaka, T., Hashimoto, N., Nakata, M., Ito, T., Ino, S., & Ifukube, T.
(1996). Analysis of toe pressures under the foot while dynamic
standing on one foot in healthy subjects. Journal of Orthopaedic &
Sports Physical Therapy, 23, 188-193.
Wenger, D. R., & Leach, J. (1986). Foot deformities in infants and
children. Pediatric Clinics of No rt h America, 33, 1411-1427.
48