其他摘要：This study was intended to examine the relationships between the speed of a kicked ball by instep-kicking, the speed of a kicking foot, and the contacting time of the kicking foot with the kicked ball. Experiment was made in two parts: In Experiment I, using three well-trained subjects, the speed of a kicked ball was measured by a speedometer installed a magnetic generator and the speed of a kicking foot was measured by a pair of micro-switches. In Experiment II, using six untrained subjects, both speeds were calculated from a 16mm movie film. In both experiments, the contacting time between the kicking for with the ball was measured by the use of electrically conductive plastic material pasted on the shoe and the ball. Following results were obtained from this study. 1.The speed of a kicking foot had a high relationship with the speed of a kicked ball, and the former was found to de contributing greatly to the latter. 2.It was found that the swing of a kicking foot was accelerated till it contacted the ball, and this phenomenon was more prominent for the well-trained than the untrained. From this, it might be considered that the well-trained subjects had better efficiency in performing their skills. 3.The contacting time tended to become slightly longer when the speed of a kicked ball was great, but there were large intra-and-inter personal differences. This seemed to be influnked by a flexing and extending movement of a kicking foot at the ankle joint when giving impact on the ball.
