Immediate but not prolonged effects of submaximal eccentric vs concentric fatiguing protocols on the etiology of hamstrings' motor performance fatigue.

Purpose: Our study aimed to compare the immediate and prolonged effects of submaximal eccentric (ECC) and concentric (CON) fatiguing protocols on the etiology of hamstrings' motor performance fatigue.

Methods: On separate days, 16 males performed sets of 5 unilateral ECC or CON hamstrings' contractions at 80% of their 1 Repetition Maximum (1 RM) until a 20% decrement in maximal voluntary isometric contraction (MVC) torque was reached. Electrical stimulations were delivered during and after MVCs at several time points: before, throughout, immediately after (POST) and 24 h (POST 24) after the exercise.

Impact of Hip Flexion Angle on Unilateral and Bilateral Nordic Hamstring Exercise Torque and High-Density Electromyography Activity.

Background: In the bilateral Nordic hamstring exercise (NHE), hamstrings operate at relatively short lengths, which may limit the efficacy of the NHE in hamstring injury prevention.

Objectives: To examine knee flexion torque and biceps femoris long head (BFLH) and semitendinosus (ST) high-density electromyography (EMG) activity during the unilateral and bilateral NHE, performed with either neutral (NHE0) or 90°-flexed (NHE90) hips.

Methods: In this laboratory study, exercises were performed on a novel device at the eccentric 1-repetition maximum load defined for 90° to 15° of knee range of motion.