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European Journal of Applied Sciences – Vol. 9, No. 6
Publication Date: December 25, 2021
DOI:10.14738/aivp.96.11345. Fujii, K. (2021). Verification of Changes in Body Proportions in Humans. European Journal of Applied Sciences, 9(6). 365-373.
Services for Science and Education – United Kingdom
Verification of Changes in Body Proportions in Humans
Katsunori Fujii
Graduate School of Business Administration and Computer Science
Aichi Institute of Technology, Yachigusa, Yakusa-cho, Toyota City
ABSTRACT
So far, the growth curves proposed by Scammon (1930) have been often used to
advantage when explaining the changes in human proportions. With regard to these
explanations, the growth was understandable if seen as the relative growth of the
general growth pattern for things such as height and weight and the neural growth
pattern showing growth of the head. However, the point here is that the validity the
logic for the growth curves proposed by Scammon almost 90 years ago should
obviously be tested. Even assuming that the growth curves of Scammon (1930) were
to be re-examined, the changes in human proportions can probably not be verified
simply with the differences between the general and neural type growth patterns
alone. Thus, it is necessary to verify the actual height and weight growth patterns
and the head growth pattern. Therefore, the present study attempts to verify the
changes in human proportion by applying the wavelet interpolation model to
growth distance values obtained through measurements of growth in height and
head circumference from early childhood to adults, and to analyze the behavior of
the velocity curves of height and head circumference derived as differential curves.
As result, this study was able to provide unequivocal findings on the changes in
proportion by applying the wavelet interpolation model proposed by the author
(1999) (2006). However, the study had the limitations that there was no
longitudinal data on the organs, actual face length, or longitudinal data on head
circumference.
INTRODUCTION
The author (2013b) has previously analyzed growth patterns in four-legged animals, and found
that large four-legged animals reach an adult weight in about two years. The weight growth
curves followed by these animals differ greatly from the growth curves of humans. More
recently, citing the proposed Fujimmon growth curves the author (2017) showed that their
growth curves are a mixed type of the general and neural types. If anything, they are closer to
the neural type. In other words, puberty was not detected in these animals. In the earlier study
by the author (2013b), Japanese macaques and similar animals showed a slight pubertal peak
in weight growth, although it not as long as the peak in humans. Thus, in non-primate four- legged mammals, the growth pattern does not differ depending on the part of the body. Rather,
they grow uniformly and as a result there is no change in their proportions as they grow. In
contrast, it is well known that the physical proportions of humans differ significantly during the
growth process. Stratz (1921) proposed a proportion diagram of humans from birth to
adulthood, and showed that during early childhood humans are about 4 heads tall, whereas in
adults this had changed to 8 heads tall.
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European Journal of Applied Sciences (EJAS) Vol. 9, Issue 6, December-2021
Services for Science and Education – United Kingdom
The question, then, is why humans change in proportion as they grow. One theory is that while
growth in head size approaches quite closely to that of adults in the first half of the growth
period, as in four-legged animals, body size continues to grow even after that. Consequently, it
is conjectured that the change in proportion occurs relatively. This is closely related to upright
walking on two legs in humans, and is thought to be a result of evolution. For humans, growth
of the brain is a priority, and the period referred to as puberty is necessary for growth to protect
the brain and facilitate brain activation. The brain is enhanced in this period. It may be
conjectured that changes in human proportions became entrenched as a result. But what is the
best way to prove these changes? As mentioned above, the growth pattern of the head differs
from the growth pattern of the body. Therefore, it would be useful to verify the phenomena in
which the growth of the body enters puberty after the growth of the head reaches a plateau,
rapidly growing afterward to achieve an adult form. However, there have been no reports to
date clearly verifying these phenomena.
The growth curves proposed by Scammon (1930) have been often used to advantage when
explaining the changes in human proportions. With regard to these explanations, Takaishi
(2003) said that growth was understandable if seen as the relative growth of the general
growth pattern for things such as height and weight and the neural growth pattern showing
growth of the head. However, it should be noted that in the age-related changes of the head and
body, the growth of the mandible shows a general growth pattern. The changes in proportions
can be explained conveniently when the growth patterns of Scammon (1930) are used in this
way. Because of this convenience, however, growth researchers today have come under the
illusion that the changes in human proportions have already been proven. For example, Tanner
(1962)(1978), Takaishi et al. (1981), and Matsuura et al. (2005), have cited Scammon’s growth
curves but have not tested their credibility or the changes in human proportions. Kimura
(1966) cited Scammon’s growth curves in explaining changes in proportions from differences
in the changes with age in measurements of height, head circumference, and face height, but
the scientific basis is lacking. The point here is that the validity the logic for the growth curves
proposed by Scammon almost 90 years ago should obviously be tested. Even assuming that the
growth curves of Scammon (1930) were to be re-examined, the changes in human proportions
can probably not be verified simply with the differences between the general and neural type
growth patterns alone. Thus, it is necessary to verify the actual height and weight growth
patterns and the head growth pattern.
This study attempts to verify the changes in human proportion by applying the wavelet
interpolation model to growth distance values obtained through measurements of growth in
height and head circumference from early childhood to adults, and to analyze the behavior of
the velocity curves of height and head circumference derived as differential curves.
METHODS
Data sets
Growth records were obtained for height, weight, chest circumference, and head circumference
for children age 0 to 6 years old entered in the 1970 version of the physical growth records for
infants and young children published by the Ministry of Health, Labor and Welfare. Next, the
head circumference and growth records from age 5 to 20 years old described in a report by
Okuda (1971), published in the journal Anthropological Science, were obtained. The growth
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Fujii, K. (2021). Verification of Changes in Body Proportions in Humans. European Journal of Applied Sciences, 9(6). 365-373.
URL: http://dx.doi.org/10.14738/aivp.96.11345
distance values for the obtained head circumference and height measurements from age 6 to
17 were extracted.
Analytical method
Wavelet interpolation method
The Wavelet Interpolation Model (WIM) is a method to examine growth distance values at
adolescent peak. A growth curve is produced by data-data interpolation with a wavelet
function, deriving the growth velocity curve obtained by differentiating the described distance
curve to approximately describe the true growth curve from given growth data. The
effectiveness of the WIM lies in its extremely high approximation accuracy in sensitively
reading local events. Details on theoretical background and the basis for this effectiveness are
omitted here as they have already been set forth in prior studies by Fujii (1995, 1999, 2006).
Growth distance and velocity curve of height is described by wavelet interpolation model as in
the following two graphs.
Figure 1. Growth distance curve of height described by wavelet interpolation model
Growth distance curve