1983 年 32 巻 1 号 p. 8-16
The purpose of this study was to determine the growth and developmental changes and the sex difference in anthropometric characteristics, muscular strength, and flexibility in 205 junior high school competitive swimmers.
Factor analytic technique was applied to three different correlation matrices, each of which consisted of 14, 12, and 15 selected variables in anthropometric characteristics, muscular strength, and flexibility domains, respectively.
The main results can be summarized as follows;
1) Among 2 extracted factors representing anthropometric characteristics domain, physique (factor 1) grew gradually as the age increased in both sexes. Amount of the physique growth for boys was, however, greater than that for girls. Physique of boys in the 8th and 9th grades was larger than that of girls.
Body fat (factor 2) for girls appeared to be greater than that for boys.
2) Among 3 extracted factors representing muscular strength domain, static strength (factor 1) developed gradually as the age increased in the both sexes. Amount of the development for boys was greater than that for girls, and this ability of boys was greater than that of girls.
Muscular endurance in fast muscular exercise (factor 2) for boys became to be greater than that for girls as the age increased.
Dynamic strength of shoulder-arm girdle (factor 3) for boys of the 8th and 9th grades was greater than that for girls.
3) Among 6 extracted factors reprsenting flexibility domain, trunk rotation flexibility (factor 2) and ankle extension and mobility flexibility (factor 5) for girls were much greater than those for boys.
Trunk extension and flexion flexibility (factor 6) for girls seemed to be greater than that for boys. Development of this ability in accordance age increase was found only in boys.
In contrast, no differences between sex were found in trunk lateral flexibility (fator 1) and shoulder flexibility (factor 4) .