Pathomechanics of the throwing shoulder.

Many anatomic, physiological, and biomechanical alterations have been observed in overhead athletes who present with painful shoulders. This is probably due to the complex kinetic chain mechanics required in the overhead throwing or serving motion. Any alteration along the kinetic chain can result in deficits in force production or increase in joint loads in other parts of the chain. The "disabled throwing shoulder" (DTS) is a general term that describes the limitations in function that exist in symptomatic overhead athletes. DTS typically results from a "cascade to injury" with alterations in the kinetic chain. Evaluation of athletes with the DTS should include examination of the local and distant anatomic injuries and screening for physiological (muscle inflexibilities, weakness, or imbalances) or biomechanical (motions, positions) alterations.