抄録
The purpose of this study was to clarify the role of each upper limb and trunk during the forward swing of T-batting motion by using an instrumented bat via an inverse kinetic approach. Seven collegiate male baseball players' motion were captured by VICON 612 system (9 cameras, 250Hz) and kinetic data of each hand were collected by using a bat instrumented with strain gauges (1OOOHz). The torque impulse about the shoulder adduction/abduction axis was the largest among all calculated values. The sum of the positive works generated by the knob-side upper limb was considerably larger than those generated by the barrel-side upper limb, which indicated that the role of the knob-side upper limb was to obtain the bat head speed during the forward swing. As for the negative works, the barrel-side upper limb generated the greater sum of work, which indicated that this limb may have been used as energy absorber. The torso joint play a significant role to accelerate angular rotation of trunk and endure the load due to centripetal force exerted on the bat prior to impact.
