The purpose of this study is to document the rates of youth baseball player demographics, incidence of arm pain, usage of different pitch types, and degree of internal rotation contracture in the throwing versus the non-throwing shoulder. We followed a subgroup of players for a year to see if a particular stretch would help reduce the internal rotation contracture.

Introduction: Overhead throwing can cause contracture of the shoulder posterior-inferior glenohumeral ligament which can lead to injuries such as superior labral tears. We show that instruction on stretching can favorably alter progression of posterior contractures.

Methods: 1261 male baseball players ages 7-15 completed a questionnaire and shoulder examinations. Measurements of rotation of both shoulders were made with the subjects in the supine position with the scapula stabilized. Glenohumeral internal rotation deficit (GIRD) was calculated. Pitch type and player position, among other variables, were recorded. The prospective cohort was 175 players who were examined twice a year apart. Players with excessive GIRD (exGIRD) were given stretching instruction, and the control group was those without exGIRD who were not given instruction. Change in GIRD as a result of this intervention was documented.

Inclusion Criteria:

• male
• baseball player
• ages 8 to 15

Exclusion Criteria:

• female (suspected hormonal/gender influences on capsular elasticity)
• prior throwing arm surgery

1261 male baseball players ages 8 to 15