Though baseball pitching is assumed to achieve proper technique in which a great deal of energy is imparted from the trunk to the throwing arm, through a kinetic chain of the entire body, few studies have answered the question of how segmental energy is generated/transferred by muscles and intersegmental joint forces. The purpose of this study was to calculate the mechanical energy produced by the individual joint moments or joint forces in throwing, and further breaking down the joint moments into their muscular and non-muscular interactive moments, assessing their contribution to the generation of mechanical energy. The pitching motion of eight collegiate baseball pitchers was measured using a three-dimensional motion capture system. A model including multiple segments and joints of the throwing arm, non-throwing arm and trunk was developed to establish the relationships between causal muscle work and distributed segmental energy. Using the model, the mechanical energy of each segment was decomposed int...