Joint torque and electromyographic activity during eccentric exercise for hip adductors at different hip flexion angles

Abstract

Our objective was to investigate the effects of three hip flexion angles (0°, 45°, and 90°) and leg dominance on peak joint torque, angle at peak torque, and peak electromyographic activity (EMGA) of the adductor longus during bilateral eccentric hip adduction. Sixteen recreationally active participants completed bilateral eccentric contractions at each hip flexion angle using a custom-built dynamometer. The primary outcome measures were peak adduction torque, angle at peak torque, and EMGA of the adductor longus. A 3 × 2 repeated measures ANOVA was used to assess the effects of hip angle and leg dominance. Hip flexion angle had a significant main effect on peak torque (F(2, 30) = 15.75, p < 0.01), with peak torque significantly lower at 90° compared to 0° and 45°. No significant effects were observed for leg dominance or interaction. No significant main effects of hip flexion angle, leg dominance, or their interaction were observed on peak EMGA or peak torque angle. Eccentric hip adduction strength is reduced at 90° of flexion, likely due to mechanical disadvantage, while neural activation remains unchanged. These findings support the use of less flexed positions in eccentric training protocols for adductor strength development or injury prevention.