Dissociation between fatigued power output and traditional peak torque for isokinetic hamstring:quadriceps ratios in professional soccer players

Muscle strength imbalance assessment (e.g., hamstring-to-quadriceps ratio, H:Q) using traditional peak torque isokinetic measurements has been shown to be a weak risk factor predictor of future lower-limb injuries hamstring strain and anterior cruciate ligament tear). In soccer, power-related tasks are commonplace most likely occur during fatigued high-velocity actions. Thus, it is reasonable that calculating H:Q power output may serve as an alternative torque-based H:Q. We aimed investigate the relationship calculated from non-fatigue fatigue conditions. Seventy-nine professional soccer players (25.6 ± 4.9 years old; 78.7 8.1 kg; 179.4 6.7 cm) performed concentric knee extension-flexion contractions at 60°.s−1 (five repetitions) 300°.s−1 (30 repetitions, trial). Traditional was highest obtained five repetitions 60°.s−1. Power H:Qnon-fatigued average 2nd, 3rd 4th H:Qfatigued last three trial. Weak (rs = 0.27) moderate 0.49) correlations were found between H:Qfatigued, H:Qnon-fatigued, respectively. The present data suggested differs H:Q, particularly in players, which warrants further investigation on potential use ratios for injury prediction.