Leg Length Increase/Decrease in Japanese in the Latter Half of the 20th Century.

Abstract

In order to determine whether the legs of the Japanese have continued to lengthen, two nation-wide anthropometric data sets from the MITI and Ministry of Education were referred to. Based on the cross-sectional and longitudinally-followed mean value observations, we can conclude that until the 1970s the Japanese had become taller due to increasing leg length. Since the 1980s, however, increase in leg length (crotch height and estimated leg length) has declined relative to height increase, especially in young males, whereas in young females relative leg length to height continues to increase if only a little. The main cause of the absolute and relative shortening of the legs in young males can be attributed to the greater increase of weight and trunk circumferences resulting from subcutaneous fat accumulation. Thus we can conclude that the Japanese have become taller and bigger while retaining their original linear body proportion. These proportions will remain unchanged so long as the gene pool remains unchanged.