インステップ・キックの習熟過程の分析

Abstract

The intention of this Study was to investigate the changes of the technique and physical fitness of the beginners after one-year training of the instep kick in football. The subjects were nine students (18-19 years old) who undertook the training regimen. The control group consisted of two players of the Japan junior national team (19 years old). The training lasting 20 minutes was carried out twice a week for one year except the vacation of the university. Data were collected while the subjects kicking a standing ball by the instep kick three times by means of videotape together with the EMG recording. Their physique and physical fitness were also measured. The following findings were obtained. 1) The motion analysis showed an increase in the range of the forward swing of the kicking leg, the shift range of the hip, the swing speed of the leg, and the angle of the ankle joint at the impact. They were considered to be the factors contributing to the increase of the ball speed. 2) The contraction patterns of the M. biceps femoris and M. quadriceps femoris as revealed by the EMG indicated the active extension of the hip joint. The improvement of the fixation of the ankle joint was recognized by the changes in the discharge of the M. tibialis antrior and M. gastrocnemius in the EMG. 3) There was a little influence of the one-year training on the physical fitness. It can be said that the improvements were mainly attained in the skill as shown by 1) and 2).