Modulation of upper limb locomotor function via transcutaneous electrical stimulation of spinal cord nervous system

This paper introduces a method of utilizing transcutaneous electrical spinal-cord stimulation (TcESCS) to activate locomotor function of upper limb. TcESCS is electrophysiological technique to modulate neurophysical function by electrically stimulating the neural structures in spinal cord through skin, tissue, and dura. In this study, we investigate the effectiveness of different TcESCS parameters including frequency, intensity and duration of stimulating current as well as placement of electrodes. Multi-sites electrodes are placed onto subject's nape portion over spinal cord segment C5-T1. Surface electrodes are used to record the EMG signals and generate activity map of biceps and triceps brachii muslces. The result shows that TcESCS current at 10 Hz, 200 us and 25 mA is most effective for single site stimulation. The multi-sites TcESCS has a larger EMG response than single site. From the EMG map, we find that spinal cord segments C5, C6 and C7 are highly relevant to biceps brachii muscle. Segments C7, C8 and T1 are highly relevant to biceps brachii muscle.