Motor-evoked potential changes during human muscular fatigue – A triple stimulation technique study

Methods: Twenty-three healthy subjects participated in the study. The exercise protocol comprised a pre-exercise period, a 2 minutes lasting fatiguing exercise by repetitive maximal voluntary contractions (MVC) of the abductor digiti minimi muscle at 0.5Hz, and a 10 minutes lasting post-exercise period. We applied the triple stimulation technique (TST) as previously described by Magistris et al. (1998). Muscular force was recorded during all experiments. TST measurements were performed at defined intervals during the exercise and recovery. In 2 sets of experiments, the responses were either facilitated by a muscular contraction of 20% MVC (experiment 1), or were performed during muscular relaxation (experiment 2).