This research is aimed at examining age-related changes of postural sway when people stand upright, examining external effects which can be exerted upon the postural sway (experiment 1), and also analyzing specific changing characters of posture-control by sudden impacts (experiment 2). The total number of subjects was 115, who are in twenties through seventies and 75 of them were participated in experiment 2. In experimen 1, the subjects were examined for 25 seconds respectively while standing upright with both feet and with eyes opened, standing upright with both feet and with eyes closed, and standing upright with a single foot and with eyes opened. In experiment 2, only while standing upright with both feet and with eyes opened they were examined for 5 seconds. Main findings were as follows: 1. In the single-foot standing position, the growing older exerted more important effects upon the fluctuation length and area of the center of gravity than in the both-foot standing position. 2. The standard deviation was increasing with age in the fluctuation length and the fluctuation area of the center of gravity. 3. There were no significant differences in daily variation, temperature change, and muscle burdening. 4. The recuperation from the postural sway by external impacts was so slow with age. 5. There were little differences in decrease frequencies among the subjects but younger persons.

The object of this research is to develop an interactive computerized graphic program for graphic output of velocity, acceleration and motion range of body task reference point. Human motions can be reproduced by scanning (rate = 1/60) the vidicon image, at same time, C.O.G of body segment group, and the results are stored in an Apple II P.C. memory. The results of this study can he exteneded to simulation and reproduction of human motions for optimal task design.

To study the body trunk form which is essential to clothing constructions, necessary body sizes were measured indirect1y from 216 unmarried women from 19 to 24 years old by a photographic network method. The results are obtained as follow; 1) In this study of body type measurements, the four factors of bust, abdomen, column and hip size have been divided into four-stage intervals and given the body type codes 1, 2, 3 and 4, with 1 designating the size difference of the factor with the minimum size difference of the factor with the maximum size difference from waist size. These body type codes can be easily, linguistically interpreted. In this study, among $4^4=256$ possible body types, 54 types appeared frequently. These 54 types are integrated into 6 groups of types by clustering analysis. Representative types of each group are types 3333 and 2333 in group 1, 2233, 1233 and 1332 in group 2, 2222, 1222 and 1223 in group 3, 2223 in group 4, 2323 and 2322 in group 5, and 3323, 3223 and 3322 in group 6. In the types of groups 1, 2, and 3, the change is mainly in bust size, and in the types of group 4. is single type. In the types of group 5 the change is mainly in hip size, and in the types by groups 6 the change is mainly in abdomen size and hip size. 2) The analysis by measuring the four elements of body trunk in reference to waist size is scientific and grading of similar styles is possible in clothing construction. 3) Assuming that the human body is oval, using the calculating method, the size of girth, which cannot be measured by the indirect measuring method, is obtained approximate to actual size, with an error of ${\pm}2.8cm$.

This study intends to improve the efficiencies of school works by proposing a method of determining the standard sizes of chairs and desks. To achive this purpose, eight measurements were taken of 1248 school children. The main results drawn from this study are : 1. There are significant correlations between stature and popliteal height and between stature and elbow height (seated). 2. There are significant differences between men and women of similar stature in respect of popliteal height. 3. The standard sizes of chairs and desks ought to be based on the characteristics of human body size and their relationship.

This study aims to investigate the effect of biorhythm to work performance. In order to do this, the data are collected from the manufacturing factory which produce a sportware, and the statistical test are made to testify the relationship between the number of defective items and the biorhythm chart of the workers. The number of defective items which made in the peak day, usual day, and critical day on the worker's biorythm chart are compared with each other, and the statistical test are made to see if there are difference between them, and the correlation analysis are made to see if there is any correlation between the work performance and the biorhythm chart. The result of the statistical test shows that the biorythm of the worker gives an effect to his work performance with a correlation.