LAUSR

This study examined the effects of fatigue on hamstring muscles and gluteus maximus passive and active shear modulus in hip extension (HE) and knee flexion (KF) at 20% of maximal voluntary isometric contraction performed until task failure. Measurements were taken before and after the fatigue tasks and the delta (post-pre) was calculated. No differences in the fatigue effects on passive shear modulus were seen between muscles nor between tasks. For the active shear modulus: a task × muscle interaction was seen (p = 0.002; η2p = 0.401). The results for the tasks separately demonstrated only a significant effect for muscle in KF (p < 0.001; η2p = 0.598), with different individual contributions identified between BFlh-SM (p = 0.006; d = 1.10), BFlh-ST (p = 0.001; d = 1.35) and SM-ST (p = 0.020; d = 0.91). The comparisons between tasks for each muscle demonstrated significant differences for SM (p = 0.025; d = 0.60) and ST (p = 0.026; d = 0.60); however, no differences were seen for BFlh (p = 0.062; d = 0.46). Therefore, fatigue effects induce different patterns on the hamstring muscles in HE and KF tasks when performed at 20% MVIC.