A19 野球の投球動作における最大肘伸展角速度調節に貢献する動力学的要因の分析(野球2)

抄録

Previous studies reported that the maximum elbow angular velocity related to the maximum hand velocity. Although the maximum elbow angular velocity was influenced by a motion-dependent torque (centripetal force, gyroscopic precession, and coriolis force-dependent torque), which joint motion and/or what dynamic factor causes the angular velocity were not so clear. The purpose of this study was to clarify the kinetic factors contributed to the maximum elbow angular velocity of throwing arm in baseball pitching by using a 3D dynamical model. The throwing motions were captured by 10 infrared cameras at 250 Hz for 8 baseball players. Throws were made under three different speed conditions: slow, medium, and fast. The kinetic factors were computed using the throwing model including 7 segments (trunk, right and left upper arms, forearms, and hands) with 17 degrees of freedom. The results showed that the maximum elbow angular velocity was mainly generated by the trunk counterclockwise rotation via elbow extension centripetal force. The maximum angular velocity was mainly adjusted by the trunk anterior lean via elbow extension gyroscopic precession and coriolis force.