Muscle fatigue could have a greater impact on position sense when antagonists of the movement are fatigued. Hence, this study aimed to compare the effects of antagonist and agonist exercise-induced muscle fatigue on knee joint position sense.
This within-subjects repeated-measures study included 40 subjects. Knee position sense and muscle strength were measured before and after two exercise protocols consisting of 30 consecutive maximal concentric/eccentric contractions of the knee extensors or flexors on the isokinetic dynamometer at an angular velocity of 180°/s (3.14 rad/s).
Both exercise protocols increased the absolute angular error (F1.78 = 39.89, P < 0.001; knee extensors protocol from 2.0 ± 1.3° to 3.5 ± 2.0°, knee flexors protocol from 2.1 ± 1.2° to 3.7 ± 2.2°), and no differences were detected between protocols (F1.78 = 0.034, P = 0.855). No changes were observed in the relative angular error.
Muscle fatigue affects knee position sense, and the deleterious effect is not different depending upon the muscle group fatigued. Muscle Nerve, 2011.