No effects of temporal cortex modulation on rotator cuff fatigue: a randomized, double-blind, sham-controlled, crossover clinical trial

Abstract

ABSTRACT Objective To investigate the effects of anodal transcranial direct current stimulation (tDCS) over the temporal cortex (TC) on rotator cuff fatigue. Methods In one session, 20 healthy individuals were randomly randomized to active or sham tDCS. Before, immediately after, and 30 minutes after tDCS, the external rotator's maximal voluntary isometric contraction (MVIC), Infraspinatus and posterior deltoid electromyographic signals, time to exhaustion test (TTE), GoC, and RPE were measured. After three days, subjects received different initial stimulation. Results Anodal tDCS had non-significant influence on MVICs immediately post-tDCS (p = 0.283) and 30 minutes post-tDCS (p = 0.867). TTE did not differ between anodal and sham tDCS (p = 0.845). There was non-significant difference in RPE between anodal and sham tDCS for 20 (p = 0.548), 40 (p = 0.699) and 60s (p = 0.712). There were non-significant differences in EMG data or the GRoC scale between groups. Conclusion Left temporal cortex modulation has no effect on muscular exhaustion, MVIC, RPE, or motor unit recruitment in the infraspinatus and posterior deltoid muscles of healthy volunteers.