サッカーにおけるボールストップの力学的考察

Abstract

The ball stopping skills by use of foot is one of the most important and basic techniques in soccer. From the view point of mechanics, the ball stopping is a form of the collision of the ball against the foot, and the velocity of the ball after impact depends on the reduced mass of leg and the relative velocity of the foot and ball. Accordingly this study attempted to clarify the mechanism of ball controlling movements of foot, using the photographical data and signals from the force plate and the acceleration transducer fixed to the foot during ball stopping. The results may be summarized as follows. (1) The contact time of the ball against the foot at impact was rather constant, being approximately 10ms, without respect to the ball velocity befor impact. (2) The directions of movements of the foot and the ball before impact were same. But, the relative velocity of the ball and the foot increased more when ball velocity befor impact increased. (3) In the ball stopping movement, it is considered that the ill-effect of miss-judgement of the foot may be reduced in the ball controlling where the reduced mass of leg decreases.