抄録
The purpose of this study was to clarify the role of each upper limb and trunk joints to the hitting point height in the baseball T-batting motion through inverse kinetic analysis. Twenty three collegiate male baseball players' motion were captured VICON MX system (12-camera, 250Hz), and kinetic data at each hand were collected by using an instrumented bat equipped with 28 strain gauges (1000Hz). Three heights of hitting point (high, middle, low) were set according to the baseball rules. Kinetic analysis procedures were carried out to estimate joint torques, joint torque powers and works of upper limbs and trunk. From the results obtained in this study, in case of low hitting point, joint torque of flexion-extension axis of shoulder and elbow on bat head side were larger than those of the other hitting points during down swing phase. It was indicated that the role of the head-side upper limb was to adjust the different hitting point. On the other hands, the knob-side upper limb and rotation of torso joint contribute to the acceleration of the bat head during forward swing.
