Abstract / Summary
Abstract Background Inter‑limb asymmetries are commonly observed in athletes, yet their relationship with sprinting performance remains poorly understood. While most existing research has focused on unilateral sports, a comprehensive systematic review examining the relationship between lower limb asymmetry and sprinting performance in sprint athletes is still lacking. Objective This systematic review aimed to examine the association between lower inter-limb asymmetry and sprinting performance in sprint athletes. Methods A systematic search was conducted in PubMed, Scopus, SPORTDiscus and Web of Science to identify studies investigating lower inter-limb asymmetry and sprinting performance in healthy, injury-free sprint athletes. The review was conducted in accordance with PRISMA 2020 guidelines (PROSPERO: CRD420251140520). Study quality was assessed using the Downs and Black Quality Index Tool, whilst the evidence certainty was evaluated with the GRADE framework. Results Of 4,811 articles screened, 10 studies met the inclusion criteria. In general, limited associations were observed between functional, morphological, kinetic and kinematic asymmetry and sprinting performance. However, task- and metric-specific associations were observed in individual studies. Conclusions Given the limited number of eligible studies and the substantial heterogeneity in study designs, tasks, and asymmetry metrics, drawing definitive conclusions remains challenging. The evidence synthesized in this review is mixed, and therefore does not allow for a straightforward assertion that inter-limb asymmetry is associated with reduced sprinting performance. To enhance comparability and clarify the potential role of inter-limb asymmetry in sprinting, future research should implement standardized, task-specific, metric-specific, and muscle-specific assessment approaches.