抄録
We aim to clarify the mechanism of the wrist turn in a golf swing and the effect of the acceleration pattern of the down swing on the release point. First, the mathematical model of the golf swing is assumed to be a 2-dimensional double pendulum. By applying Lagrange's equation to this system, we derive the equations of motion of the golf swing. We consider that the wrist turn begins naturally under the centrifugal force of the swing and angular velocity of the arm at the release point is very important parameters from the view point of increasing head speed. When the angular velocity of the arm and the centrifugal force which applies to the club head become sufficiently large compared to the angular acceleration and tangential inertial force, the wrist of the player begins to turn naturally without driving torque being applied to the wrist. We derive simple theoretical equations which express when and where the wrist begins to turn and effect of acceleration pattern on release point. From the derived equation, it can be seen that the acceleration pattern has large effect on the release point and velocity of swing, and ratio of club length to arm length and the cock angle are also important parameters.
