Figure 1

Study schematic. Schematic of experimental set-up (a), and an example of EMG recording in soleus muscle during contraction or relaxation tasks during light-on status or light-off status (dotted line) (b). Triangles indicate onset or termination of EMG signal. C-RT, contraction response time; EMG, electromyogram; MVC, maximum voluntary contraction; R-RT, relaxation response time.