Inter-Limb Jump Asymmetries and Their Association with Sport-Specific Performance in Young Male and Female Swimmers.

This study aimed to examine inter-limb jump asymmetries and their association with sport-specific performance in young swimmers. Thirty-eight (male, n=19; female, n=19) region-al/national level young swimmers (age: 12.3±1.2 years; height: 159.6±8.2 cm; body mass: 52.5±9.2 kg) participated in this study. Inter-limb asymmetries were assessed for single-leg counter-movement jump (SLCMJ) and single-leg standing long jump (SLSLJ). Sport-specific performance was evaluated using front crawl (i.e., 50-m and 25-m) and front crawl kick (i.e., 50-m and 25-m). The Kappa coefficient revealed a ‘slight’ level of agreement (Κ=0.156, 0.184 and 0.197 for female, male and all, respectively) between the direction of asymmetry for SLCMJ and SLSLJ, indicating that asymmetries rarely favoured the same limb during both tests. A paired sample t-test showed a significant difference (p=0.025) between asymmetry scores obtained in SLCMJ and SLSLJ. No significant difference was found in asymmetry scores between males and females (p=0.099 to 0.977). Additionally, no association between asymmetry scores and sport-specific performance was observed (p>0.05). Our findings highlight the independent nature of inter-limb asymmetries derived from SLCMJ and SLSLJ among young male and female swimmers. Further, our results suggest no association between jumping asymmetries and sport-specific performance.