Differences and correlations between horizontal and vertical single-leg jump performance, dynamic balance, and ankle dorsiflexion range of motion in male amateur rugby players according to playing positions

Abstract

Objectives: To explore the differences and correlations in the Y-Balance Test (YBT) scores, ankle-dorsiflexion range of motion (ADFROM), single-leg drop jump (SLDJ) and single-leg hop for distance (SLHD) in amateur male rugby players by playing positions and limb dominance. Design: Cross-sectional study. Setting: Argentinian amateur rugby club. Participants: Male (n = 58) senior amateur rugby players. Main outcome measures: ADFROM, YBT (anterior [AN], posteromedial, posterolateral, and composite [COM]), SLDJ and SLHD performances. Results: Forwards demonstrated different anthropometric traits than backs (p < 0.001 to 0.003; ES: − 0.508 to − 1.331), whereas the latter attained better jump performance (p < 0.001–0.05; ES: 0.297–1.349) and YBTCOM scores compared to the former, irrespective of limb dominance (p: 0.007–0.034; ES: 0.569–0.730). With regards to the associations, forwards’ BMI (rho: − 0.35 to − 0.52, ES: 0.184) and ADFROM values (rho: 0.41 to 0.53, ES: 0.184; r: 0.43 to 0.50, ES: 0.184) were associated to jump performance among both limbs. In contrast, for the backs, leg length was associated with SLHD (rho: 0.42–0.45, ES: 0.214) and YBTCOM (rho: − 0.67 to − 0.76, ES: 0.215). Likewise, ADFROM values (r: 0.44–0.56, ES: 0.185) were moderately associated to YBTAN in both limbs. Conclusions: Backs attained better dynamic balance, wider ADFROM, and better unilateral vertical and horizontal jumps performances in dominant and non-dominant limb, compared to forwards. Additionally, ADFROM maybe an important aspect to consider when aiming to improve balance and jump performance among forwards and backs.