Abstract
Some studies have reported that movements of forearm and wrist has several rolls to perform a baseball pitching. However dynamical mechanism of the forearm and the wrist are still unclear. As a step toward understanding the rolls of forearm and hand in baseball pitching, we investigated how non-muscular (e.g. centrifugal. Coriolis, and gravity) forces of the each link generates, absorbs, and transfers mechanical energy in order to produce maximum velocity. This was accomplished using multi-body power analysis derived entirely from dynamical equations of a 3D double pendulum with moving pivot model. In order to analyze based on this model, collegiate male baseball pitchier arm movements were captured by motion capture system with IkHz sampling. The analysis clarified that mechanical energy of the hand segment was transferred through internal force which was mainly dominated by centrifugal force, although muscle torque applied to the wrist joint absorbed the mechanical energy of the hand segment rather than increasing the energy.
