Side-to-Side Asymmetry of Single-Leg Repeated Deceleration-Acceleration Performance is Related to Deterioration of Running Change-of-Direction Performance in Amateur Adult Female Netball Players

Background Side-to-side asymmetry of single-leg motor-performance is hypothetically linked to deterioration of running change-of-direction (CoD) performance in games-players. Currently, asymmetry research biases single-leg motor-performance in elite male and female athletes. Asymmetry issues that influence performance and have implications for practice have not been examined for amateur adult female games-players. Aim To determine the relationships between triple-hop-for-distance (THD) absolute-asymmetry (THD-AA) and Illinois-agility-test (IAT) performance, and single-hop-for-distance (SHD) absolute-asymmetry (SHD-AA) and IAT performance, in amateur adult female netball players. Methods Twenty-three players participated (mean±SD: age 28.7±6.2yr; height 171.6±7.0cm; mass 68.2±9.8kg). Test order was THD (cm), SHD (cm), IAT (s). For THD and SHD, leg order was right, left. Practice trials preceded three measured trials. For THD and SHD, trial means were used to compute a limb-symmetry-index (LSI; %): (right ÷ left) × 100. Absolute-asymmetry (%) was calculated: 100 − LSI. Negative signs were removed. Normality of data was tested (Shapiro-Wilk). Spearman’s correlation (rs) assessed relationships. Coefficient of determination (rs2) assessed the proportion (%) of variance shared between variables. Alpha was set a priori (0.05). Results Data were (median, range): THD-AA 3.3%, 0.2-15.8%; SHD-AA 2.4%, 0.0-17.3%; IAT 19.6s, 17.8-22.9s. Relationships were: THD-AA/IAT, rs=0.54, rs2=0.29, p=0.01; SHD-AA/IAT, rs=0.31, rs2=0.10, p=0.07. Conclusion As THD-AA increased, IAT performance deteriorated. Approaching one-third (29%) of the variance in IAT performance was explained by THD-AA. Therefore, to enhance repetitive running CoD performance in amateur adult female netball players, training efforts may need to consider mitigating right-left asymmetries in sagittal plane single-leg repeated deceleration-acceleration performance as represented by the THD.