Figure 9. Phase-dependent modulation of cutaneous reflexes.
Phase-and speed-dependent modulation of cutaneous reflexes evoked by electrically stimulating the superficial peroneal nerve (single 0.2 ms pulse at 1.2 times the motor threshold) in A) semitendinosus, B) vastus lateralis and C) lateral gastrocnemius at a treadmill speed of 0.4 m/s in a spinal cat. Cutaneous reflexes are separated into 10 bins. Rectified EMG waveforms obtained with stimulation are separated into 10 bins (average of 5–17 cycles per bin). The red lines show the background level of EMG in each bin (average of ~90 control cycles). The EMG waveform shown vertically on the right of each panel is the rectified activity of the muscle across the normalized cycle. Modified from (407).