Effect of Hip Range of Motion Restrictions on Injury in Baseball Players: A Systematic Review.

Abstract

Objective To determine whether restrictions in hip external rotation (ER) or internal rotation (IR) range of motion (ROM) are related to overall injury risk in baseball players. Data sources Three databases were systematically searched from inception through September 2024 using the following keywords: hip, acetabular, acetabulum, pelvis, pelvic, and baseball. Study selection Studies were included if the authors evaluated baseball players, assessed clinical hip measures, and related these measures to injury. Two independent reviewers screened 495 studies, with 17 meeting final inclusion criteria. Authors of 13 studies evaluated youth or high school players, and authors of 4 examined professional players. Data extraction Two investigators independently extracted demographic variables, and the primary outcomes included bilateral hip IR and ER ROM measurements and their relationship to injury. Study quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS), with a mean score of 14 ± 3. Data synthesis Analysis included over 4000 players across 17 studies. Compared with injured players, healthy youth or high school players had 2° more ER ROM and 3° more IR ROM in the stance hip as well as 1° more ER ROM and 4° more IR ROM in the stride hip. Out of 9 studies in which hip ROM was compared between healthy and injured youth players, authors of 5 studies related stride-leg IR ROM to injury, authors of 2 related stance-leg IR ROM to injury, authors of 3 related stance-leg ER ROM to injury, and authors of 1 related stride-leg ER ROM to injury. Conclusions Based on these observations, clinicians may consider monitoring IR ROM of the stride leg and ER ROM of the stance leg in baseball players and consider developing injury-prevention or rehabilitation programs to prevent the onset of hip rotational ROM restrictions. However, due to the heterogeneity of the included studies and the small differences in ROM, no strong clinical recommendation can be made before authors of future prospective studies relate clinically significant hip ROM restrictions to baseball injuries.