野球打撃動作における上半身の動力学的貢献分析

（内外角に異なる打点条件に対するバット運動生成メカニズムの変容）

抄録

The purpose of this study was to investigate the changes in the bat-motion generation mechanism in baseball tee batting at different hitting points during induced speed analysis of baseball whole-body batting motion. The whole-body with bat was modelled as a system of 16-rigid linked segments. One male experienced baseball player, who has 10-year experience and was right-handed hitter, performed a baseball tee batting. He was instructed to hit a teed ball set at his belt height and placed at 3 locations (inside, center and outside) toward the net as strong as possible placed in 3 directions (left, center and right). The motions were captured with a motion capture system, and kinetic data were measured with 2 force platforms and an instrumented bat. The results obtained in this study showed that the flexion-extension torque at the knob-side shoulder joint showed large positive contribution rather at inside ball batting than that at outside ball batting, and that the flexion-extension torque at the knob-side elbow joint was negative contributor to the generation of bat head speed rather at inside ball batting than that at outside ball batting when focusing on upper-body.