In this paper, effects of physical activity in daily life on m. triceps surae were considered comparing the cadavers with decubitus with those without decubitus on muscle weight and relative muscle weight. The muscles were dissected from 18 cadavers (13 males and 5 females) aged 36 to 90 which were preserved in a 10% formalin solution for about one year. Immediately after the removal, weights of gastrocnemius and soleus were measured.
Mean values of the muscle weights of soleus, gastrocnemius and combined total were heavier in male than in female. Those of the relative weights of soleus were larger than those of gastrocnemius in both sexes. The muscle weights showed remarkable inter-individ-ual variations and sexual differences. The decubitus group (non-active group) showed lighter muscle weight than the normal group did in both sexes. However, there were no differences in the relative muscle weight between both groups in both sexes.
The rate of lack of m. plantaris was 11.1%.
From these results, it was suggested that the relative muscle weight might not be influenced by physical activity in daily life but the muscle weight might change consid-erably related to it.

In order to investigate an effect of exercise on physical growth and maturation, physical characteristics (height, weight, chest girth, bi-acromial diameter, bi-iliac diameter and span) and skeletal age were measured for 34 boys of control group and 37 boys of soccer group. Skeletal age was evaluated from hand wrist radiographs by TW II method.
Result showed that the values of physical characteristics in the control group were larger than those in the soccer group, but the differences were not statistically significant. Mean skeletal age in each age group of the soccer group closely approximated the chronological age, but that in the control group was inclined to proceed earlier than the chronological age. The correlations of all the physical characteristics with skeletal age were higher than with chronological age in both groups. Those correlations with chrono-logical age in the soccer group were lower than those in the control group.
Based on the values of the subjects in this study, this fact leads to the conclusion that skeletal age is in fact a better predictor of physical characteristics than chronological age is. Physical characteristics of the boys in the soccer group correlate higher with skeletal age than with chronological age. In relation to the skeletal maturation, each physical characteristics in the control group shows a similar growth. In the soccer group, weight and chest girth show differences of growth from other physical characteristics.