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 (ADF_ROM), 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: ADF_ROM, 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 YBT_COM 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 ADF_ROM 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 YBT_COM (rho: -0.67 to -0.76, ES: 0.215). Likewise, ADF_ROM values (r: 0.44-0.56, ES: 0.185) were moderately associated to YBT_AN in both limbs.

Conclusions: Backs attained better dynamic balance, wider ADF_ROM, and better unilateral vertical and horizontal jumps performances in dominant and non-dominant limb, compared to forwards. Additionally, ADF_ROM maybe an important aspect to consider when aiming to improve balance and jump performance among forwards and backs.

Keywords: Athletic performance; Balance assessment; Rugby union; Unilateral training.