2015 年 81 巻 824 号 p. 14-00678
We aim to clarify the mechanism of the release point of the golf swing and the effect of the acceleration pattern of the down swing on the dynamic behavior at the release point. We consider that uncocking begins naturally without driving torque applied to the wrist joint when the angular velocity of the arm and the centrifugal force become to be sufficiently large compared to the angular acceleration and tangential inertial force,. We derive simple approximate equations which express the relationship between angular velocity and acceleration at the release point. By using the derived equations and the acceleration pattern of the down swing, we develop calculation methods to estimate the effect of the acceleration pattern expressed by the polynomial of time on the dynamic behavior at the release point which may affect significantly on the head speed. We discuss how the patterns affect to the release point for two types of acceleration pattern which are expressed by the 1st order function of time. Through the discussion, it can be seen that acceleration pattern which has positive gradient gives high angular velocity of the release point and later release point, and negative gradient pattern shows low angular velocity and earlier release point and these results can explain mechanism of so-called late hitting.