1983 Volume 49 Issue 2 Pages 78-95
The sole replicas were obtained by Monkemoller-Kopelan method from 878 children aged 6, 11, 13, 14, 15 and 21. In these replicas the length and width of the sole and the big-toe angle were measured, and the development of the foot shape by age and sex, the process of the deformation of the foot and the characteristics of the sole were observed. In this report, the author observed the big-toe angle which is said to be most influenced by the sole deformation caused by footwear, and discussed the appearance of the angle and its significance. 1) In the males the width of the sole increased according to the increase of the length, while in the females the width decreased to show a narrow foot shape when the length was beyond 21.Scm. 2) In many cases the big-toe angle became large in parallel with age, which was particularly true in the females. It suggests that the male supports the body weight on the whole sole but the female does the same on the big-toe. 3) The decrease of the foot width observed in the females is related to the appearance of the big-toe angle, and the narrow foot is able to support the body weight easily by the aid of the increasing big-toe angle. 4) The appearance of the big-toe angle is due to the characteristic walking of human beings on two feet keeping the body upright. The acquired skill in walking is considered to accelerate the formation of the big-toe angle in childhood.