成人女性におけるオーバーハンドスロー動作の検討 : 投距離に影響を与える体力要因を考慮して

Abstract

This study was to examine overhand throwing motions of adult women. Eleven physical fitness test items and measurement of throwing distance (using softball) were administerd to 96 adult female students. The multiple regression equation to estimate throwing distance was calculated by the stepwise method. The differences between estimated distance and measured distance were calculated. Ten subjects with higher residual were selected as Excellent group, and ten with lower residual were selected as Poor group. Overhand throwing motions of selected subjects were filmed simultaneously from side and overhead view by two cameras. Dynamic variables such as displacement, time, velocity, angle and angular velocity were obtained from film analysis. Excellent group showed longer throwing distance (p&lt0.01), while there was no significant difference in fitness test items between two groups. Excellent group showed higher initial velocity of ball at release (p&lt0.01). Judging from these results, it seems that longer throwing distance was caused by higher initial velocity of ball, and higher initial velocity of ball was produced by rational throwing motions. Characteristics of rational overhand throwing motions of adult women which were verified in this study were as follows: 1) greater backward rotation of shoulder of throwing-hand side in the horizontal plane during preparatory phase (step motion), 2) greater back-swing of throwing-hand during preparatory phase, 3) faster forward rotation of shoulder of throwing-hand side in the horizontal plane during throwing phase (from front foot contact to ball release), 4) skillful whip-like action, 5) well-timed wrist (snap) action. The results of this study suggest that five these points should be emphasized in motor learning of throwing for adult women.