Experimental protocol and test battery.

The protocol (Figure 1a) included six 7-minute bouts of a repetitive reaching task, interspersed by 5-minute breaks comprising two ratings of perceived fatigue and a 3-minute mental task. A test battery (TB, Figure 1b) was performed before, immediately after, and one hour after the work period. Both x-axes show time in minutes. EMG, electromyography; ECG, electrocardiography; BP, blood pressure; MVC, maximal voluntary contraction; PPT, pressure pain threshold; TC, test contraction.