抄録
The purpose of this study was to investigate the torso twisting during the spiking motion of Japanese elite
male volleyball players. Spiking motion of volleyball players was videotaped by two high-speed VTR cameras
operating at 250 Hz to obtain three-dimensional coordinates data of the body segments and the center of the
ball. The velocity of the ball, hand and shoulder and twisting angle of the torso were calculated. The results
were summarized as follows; (1) The large twisting angle and the large angular velocity of the torso twisting
contributed to increase the hand velocity at the impact. (2) Maintaining the shoulder velocity in the direction
of the swing at the impact help to achieve large ball velocity. (3) To obtain large shoulder velocity in the
direction of swing at the impact, they used two types of torso motion: the first type predominated forward flexion
of the torso, the second one predominated forward twisting of the torso. Although most of the players combined
the both of torso motions during spiking motion, the twisting type is preferable to obtain large shoulder
velocity and then ball velocity as a result.
