B-37 野球打撃におけるインパクト時のバット角度を決定するメカニズム : 打者の両手がバットに加えた力系の貢献度を定量化する方法論の提案(打撃動作)

抄録

The purpose of this investigation was to develop a method for calculating contributions of the force-couple system applied to the baseball bat to the orientation of the bat at ball impact. A collegiate baseball player was asked to perform tee-batting in a direction toward the center field. A motion capture system operating at 500 Hz was used to determine three-dimensional coordinates of reflection markers attached to the bat. The resultant force and the resultant moment exerted on the bat by the batter's hands were determine with the inverse dynamics approach and their contributions to the orientation of the bat were computed with the forward dynamics approach. Horizontal angles and vertical angles of the bat calculated with the forward approach were in excellent agreement with the kinematically measured angles of the bat. A sample analysis of collegiate baseball player indicated that the horizontal and vertical angles were produced by the positive contributions of the couple moment that exceeds the negative contributions of the moment of resultant force.