Infraspinatus Cross-Sectional Area and Shoulder Range of Motion Change Following Live-Game Baseball Pitching

Context:Following a baseball pitching bout, changes can occur to glenohumeral range of motion that could be linked to injury. These effects are in part due to the posterior shoulder’s eccentric muscle activity, which can disrupt muscle contractile elements and lead to changes in muscle cross sectional area (CSA), as measured by ultrasound. Objective:To assess changes in muscle CSA, and range of motion immediately before and after pitching, and days 1-5 following pitching. Design:Repeated measures. Setting:Satellite athletic training room. Patients:Ten elite college baseball pitchers participating in the fall season (age: 18.8±1.2 years, height: 189.2±7.3 cm, mass: 93.1±15.3 kg, 8 starters, 2 long relievers). Intervention:A pitching bout of at least 25 pitches (63.82±17.42 pitches). Main Outcome Measures:Dominant and non-dominant infraspinatus CSA, as measured by ultrasound, and glenohumeral range of motion including internal rotation (IRROM), external rotation (ERROM), and total range of motion (TROM) bef...