A21 野球打撃動作における四肢関節トルク・パワー(野球1)

抄録

The roles of the upper extremities during baseball batting motion are transfer of the energy generated by the lower extremities into a bat and control the bat to place in a hitting point. Since the bat is manipulated by both hands in swing motion, the upper extremities and the bat make a closed multi-segment loop. It is therefore impossible to determine the forces and moments acting on the bat by each hand with only visual information of motion of the bat. The purpose of this study was to investigate three dimensional kinetics of each joint in the upper and lower limbs by using 1) an instrumented baseball bat to measure forces and moments exerted on the grip handle of the bat, and 2) two force platforms to measure ground reaction force and moment exerted on each leg. Two collegiate baseball players participated in the experiments. The positions of marker of the body segment endpoints and the bat were captured with VICON motion analysis system operating at 250Hz. Kinetic analysis of joints were realized with inverse dynamic solution with the data obtained by the instrumented bat and the force platforms. The kinetic results such as joint torques and joint torque powers indicated the roles of each upper limb and each lower limb during baseball batting motion.