Abstract
OBJECTIVE: The aim of this scoping review was to evaluate hip internal rotation (IR) range of motion (ROM) across different age groups of baseball athletes to identify those at greater risk of injury. Additional objectives included comparing hip IR ROM between dominant and non-dominant legs and between pitchers and position players. DATA SOURCES: PubMed, Embase, OVID, and CINAHL. STUDY SELECTION: Inclusion criteria required studies to be full text, written in English, involve healthy baseball athletes cleared for participation, and include measurements of bilateral passive hip IR ROM prior to any interventions. DATA EXTRACTION: Three independent reviewers systematically extracted data on population age, competition level, passive dominant hip IR ROM, and passive non-dominant hip IR ROM. When available, means, standard deviations, and sample sizes also were extracted. DATA SYNTHESIS: The initial search yielded 155 studies, of which 23 met inclusion criteria. Aggregate data were analyzed using weighted means, pooled standard deviations, and sample sizes. Athlete groups were categorized as youth (<13 years), high school, college, and professional. College and professional groups were further stratified into pitchers and position players. CONCLUSIONS: All groups exhibited deficits in bilateral passive hip IR ROM. Professional athletes demonstrated greater bilateral hip IR compared to college-aged athletes. The difference in mean non-dominant versus dominant hip IR between pitchers and position players was minimal, measuring less than two degrees.