The overhead throwing motion is a coordinated effort of muscle units from the entire body, culminating with explosive motion of the upper extremity. The throwing motion occurs at a rapid pace, making analysis difficult in real time. Electromyographic studies and high-speed video recordings have provided invaluable details regarding the involved musculature, the sequence of muscle involvement, and associated kinematic variables. The goal of the present article is to provide an overview of the kinetic chain-that is, a detailed description of the muscular coordination during each phase of pitching-and to describe specific types of pitches. An enhanced understanding of the components of the kinetic chain and the phases of the throwing motion can provide important information for rehabilitation, performance enhancement, and injury prevention.
Keywords: kinetic chain; pitching; pitching motion; shoulder injuries; throwing shoulder.