Shoulder muscle imbalance as a risk factor for shoulder injury in elite badminton players: A prospective study.

ABSTRACT

OBJECTIVES: To assess the impact of preseason shoulder testing on the risk of significant shoulder injury (SSI) in elite badminton players. DESIGN: Prospective cohort study. SETTING: Secondary care, academic medical center. PARTICIPANTS: Nineteen elite badminton players (19.37 ± 4.79 years, n = 13 males). MAIN OUTCOME MEASURES: At preseason, they had shoulder examination tests including the table-to-acromion distance and the glenohumeral rotation range of motion. The glenohumeral internal rotation deficit (GIRD) was calculated. Isokinetic internal and external rotator shoulder muscle strength was tested at 60°/s (concentric and eccentric modes) and 240°/s (concentric mode). Bilateral strength ratio (non-dominantdominant) and unilateral agonistantagonist conventional and functional ratios (FR eccentric-to-concentric) were calculated. RESULTS: During the follow-up time of 38 weeks, SSIs were assessed by an experienced sport physician and 42% of the participants sustained at least one SSI at their dominant side. The preseason GIRD and FR at 240°/s (FR240) were independently associated with SSIs (G2 = 6.28, p = .012 and G2 = 6.23, p = .013, respectively). FR240 < 0.69 (odds ratio = 28.0) and GIRD> 14° (odds ratio = 36.14) were predictors for SSIs. CONCLUSIONS: Lower functional deceleration ratio and greater GIRD are associated with a higher risk of SSI at the dominant side in elite badminton players.