New Paradigms in the Throwing Shoulder: Pathophysiology and Examination

There continues to be a high incidence of shoulder injuries in throwing athletes, with sometimes disappointing return-to-play outcomes, creating an increased need to understand the pathophysiology of the injury and to better characterize the injury during the clinical examination. Current concepts suggest that the disabled throwing shoulder is a useful construct to develop a more comprehensive view of the complex local and distant musculoskeletal alterations that can be seen associated with the clinical symptoms. The pathophysiology can be seen as a cascade to injury, in which proximal or distal deficits in motion, strength, and strength balance can affect force production, joint position, and joint loads throughout the kinetic chain. Local imbalances between force production and load can create anatomic injury or create distant imbalances that create the injury. The evaluation then becomes a more comprehensive one, necessitating a look at all areas of the kinetic chain and evaluation of them in the context of the requirements on the structures during each of the phases of the throwing motion. Specific testing for core stability, scapular stability and motion, and local muscle strength, strength balance, and flexibility needs to be performed, as well as tests for tissue injury.