Fundamental Studies fo Hitting Movements-The Electromyographical Study of Forehand-ground-strokes of Tennis-

ヒトは，足で立つことができてから現在の文明を築いてきた。上肢による作業行動や，スポーツ場面における復雑でパワフルな活動も頑丈な下肢に支えられたり，あるいは，下肢との協応が巧みになされたりしてこそ可能である。体育やスポーツにおける打球動作もまた瞬間的に力を伝える種目としてむつかしい動作といえる。今回は，サイドアームパターンの運動様式の代表として，テニスフォアハンドストロークを取り上げ，V．T．R．と筋電図を併用してボールインパクト時における，上下肢の協応の実態を明らかにしようとした。We studied about forehand-ground-strokes of tennis biomechnically by using V.T.R.set and E.M.G.analysis.The results which were obtainded,will be summarised as follows:1,Generally,remarkable bischarges were observed in the right and left sternocleidomastoideus muscles at the ball impact.Especially,in case of well trined players,more remarkable discharges were observed at the left side sternocleidomastoideus muscles on the neck,and as to untrained players,they were observed at the right side one.2,In the take back phase,it was general that considerable discharges were observed in the left side shoulder joints anterior deltoideus on well trained players.On the contrary as to the untrained players,marked discharges were seen in the right side shoulder joints posterior deltoideus.3,At the ball impact,simultaneous, continuous and active discharges were observed in both of the right and left anterior deltoideus of well trained players.On the other hand,as to the untrained players,the left side shoulder joints posterior dertoideus and the left side latissimus dorsi discharged romarkably at the ball impact.4,The inclination of no angular changes were seen in the both of the goniograms set on the wel