Influence of Dynamic Balance on Jumping-Based Asymmetries in Team Sport: A between-Sports Comparison in Basketball and Handball Athletes

Abstract

The aims of the present study were to analyze mobility, dynamic balance and lower-limb strength and the prevalence of asymmetry according to the type of sport and assess the association between inter-limb asymmetry and sports performance. A total of 23 basketball and 25 handball players performed a test battery consisting of functional movements and a jump test. Inter-limb asymmetry was calculated using a standard percentage difference equation. A between-groups comparison analysis was carried out, and Pearson's correlation coefficients (r) were calculated to establish a relationship between asymmetries and physical performance. The results found athletes in different sports to exhibit different performance in functional movements and the jump test, but no bilateral asymmetries. The reactive strength index (RSI) and stiffness asymmetries were significantly associated with the anterior reach Y-balance test (YBT) (r = -0.412; p < 0.01 and r = -0.359; p < 0.05, respectively), and the unilateral triple hop test (THTU) was negatively correlated to anterior reach, posterior lateral reach YBT and YBT composite YBT (r = -0.341 to -0.377; p < 0.05). These findings suggest that the asymmetries exhibited important dispersion not dependent upon the type of sport but on each individual and the applied test. In addition, asymmetry in anterior direction YBT showed the strongest association to the rest of the sports performance variables.

Keywords: functional test; inter-limb asymmetry; lower limb strength; sports performance.

Figure 1

Comparative analysis of mobility, dynamic balance and lower limb strength asymmetries according to the type of sport. The model was adjusted for age. Bars indicate uncertainty in the true mean changes with 90% confidence intervals. Trivial (shaded) areas were calculated from the smallest worthwhile change. Quantitative chances of better or worse effects were determined as follows: <1%—almost certainly not; 1–5%—very unlikely; 5–25%—unlikely; 25–75%—possible; 75–95%—likely; 95–99%—very likely; and >99%—most likely [25,26]. Asym—asymmetry; WB-DF—weight-bearing dorsiflexion; YBT A—Y-balance test anterior reach; YBT PM—Y-balance test posteromedial reach; YBT PL—Y-balance test posterolateral reach; YBT—Y-balance test composite of all directions; DJU—drop jump unilateral; RSI—reactive strength index; THT—triple hop test; ES—effect size.

Figure 2

Matrix correlations (Pearson’s r, 95% confidence intervals) between the inter-limb asymmetry scores in functional tests and lower limb strength sports performance. The model was adjusted for age. * Statistical significance at p < 0.05. ** Statistical significance at p < 0.01. YBT A—Y-balance test anterior reach; YBT PM—Y-balance test posteromedial reach; YBT PL—Y-balance test posterolateral reach; YBT—Y-balance test composite of all directions; DJU—drop jump unilateral; RSI—reactive strength index; STF—stiffness; THTU—triple hop test unilateral.