Physeal changes and range-of-motion differences in the dominant shoulders of skeletally immature baseball players

The purpose of this study was to document range-of-motion differences and radiographic changes in the dominant shoulder of skeletally immature throwers and to determine how pain associated with throwing may relate to these changes. Seventy-nine male youth baseball players (aged 8-15 years) completed a questionnaire, a shoulder examination, and a series of radiographs to determine physeal changes and humeral retroversion. Radiographs were reviewed and interpreted by a blinded musculoskeletal radiologist. Measurement of proximal humeral physeal width revealed a significant increase on the dominant side for the entire group, in subjects with a history of symptoms during the current season, and in subjects who had never had symptoms. Visual radiographic changes were commonly found in subjects with a history of pain (16/26 [62%]) as well as in those subjects without symptoms (29/53 [55%]). Subjects had increased external rotation of the dominant arm as compared with the nondominant arm, and this pattern increased in magnitude as the throwers aged. Range-of-motion and radiographic asymmetry of the shoulders is common, is often asymptomatic, and may represent adaptive changes in this population.