出版社：Japan Society of Physical Education, Health and Sport Sciences
摘要：A study was conducted to examine how kinetic factors influence ball speed following a tennis forehand drive. The subjects were 15 male college tennis players, gripping the racket with their right hand. The players performed the forehand drive with maximum effort while aiming at a target area. The trials were filmed at 100 fps using two 16-mm movie cameras. Using Winter's method, the joint torque was determined two dimensionally on the horizontal plane for the wrist, elbow and shoulder joints, and for upper torso rotation during the stroke. The subjects were divided into two groups; a fast group (n=8) and a slow group (n=7) based on the ball speed. Despite a significant difference in ball speed between the two groups, no significant differences were observed in any items related to physique, muscle strength or pewer. The positive joint torque of the shoulder joint appeared from the first stage of the stroke, that of the elbow joint from the middle stagge, while that of the wrist joint appeared at the end of the stroke. The integrated positive joint torques (IT+) during forward swing were found to be the greatest in shoulder joint and the least in the wrist joint. The IT+ were significantly different between the fast and slow groups in all joint movements except for upper torso rotation. Individual ball speeds delivered by all subjects were positively correlated with the IT+ of the shoulder and elbow joints. From these results, it was concluded that (1) individual ball speeds are influenced considerably by the shoulder and elbow joint torques in the horizontal plane, and (2) players showing faster ball speed develop greater torques in all upper limb joint movements.
其他摘要：A study was conducted to examine how kinetic factors influence ball speed following a tennis forehand drive. The subjects were 15 male college tennis players, gripping the racket with their right hand. The players performed the forehand drive with maximum effort while aiming at a target area. The trials were filmed at 100 fps using two 16-mm movie cameras. Using Winter's method, the joint torque was determined two dimensionally on the horizontal plane for the wrist, elbow and shoulder joints, and for upper torso rotation during the stroke. The subjects were divided into two groups; a fast group (n=8) and a slow group (n=7) based on the ball speed. Despite a significant difference in ball speed between the two groups, no significant differences were observed in any items related to physique, muscle strength or pewer. The positive joint torque of the shoulder joint appeared from the first stage of the stroke, that of the elbow joint from the middle stagge, while that of the wrist joint appeared at the end of the stroke. The integrated positive joint torques (IT+) during forward swing were found to be the greatest in shoulder joint and the least in the wrist joint. The IT+ were significantly different between the fast and slow groups in all joint movements except for upper torso rotation. Individual ball speeds delivered by all subjects were positively correlated with the IT+ of the shoulder and elbow joints. From these results, it was concluded that (1) individual ball speeds are influenced considerably by the shoulder and elbow joint torques in the horizontal plane, and (2) players showing faster ball speed develop greater torques in all upper limb joint movements.
