Fundamental Study of Hitting Movement -Electromyographic study of initiate movement on golf swing-

ボールを打つという動作に限らず,全力で力を発揮するような動作におけるinitiate movementは,身体重心の近位に相当する腰部の動きにより始まると言える｡四肢は,それによって生じた力をより効果的に増幅させることに参画しそこに力の連動が在る｡よい動きを習得したり,指導する上においてこれら一連の力の連動の実態を知ることは言うまでもない｡今回は,主としてゴルフスイングにおける躯幹と両脚の動きに注目し,initiate movementの実態を明らかにしようとした。The ground reaction forces of the leg-to-leg shift of weight and the intitiate movement during the golf swing in relation to trunk movements were clasified through studies of 3 male subjects. These tests were completed through the use of force plates, electromyograms, and V. T. R. The results were summarized as follows. 1) The studies of the intitiate movement of the forward swing at the trunk begining with the extention of the right hip joint were followed by studies which showed the internal rotation of the right side of the trunk and support of the back. Adduction of the left hip joint and the extention of the left knee joint were also clasified. 2) The subjects who displayed a pattern of discharge from the extention of both legs in forward swing phase experience minimal change of shift in the ground reaction forces. 3) One subject showed a difference in shift of ground reaction forces between the practice swing and actual swing. This subject displayed a large discharge in the M. adductor longus immediately before the top of the actual swing, which produced an early shift of weight to the left leg