This study had two objectives: (a) revealing the difference in finger segments between the conventional and finger models during aimed throwing and (b) examining the central nervous system's timing control between the wrist torque and finger torque. Participants were seven baseball players. Finger kinetics was calculated by an inverse dynamics method. In the conventional model, wrist flexion torque was smaller than that in the finger model because of the error in ball position approximation. The maximal correlation coefficient between the wrist torque and finger torque was high (r = .85 ± .10), and the time lag at maximal correlation coefficient was small (t = 0.36 ± 3.02 ms). The small timing delay between the wrist torque and finger torque greatly influenced ball trajectory. We conclude that, to stabilize release timing, the central nervous system synchronized the wrist torque and finger torque by feed-forward adjustments.
Keywords: finger model; finger torque; overarm throwing; wrist torque.