Due to lack of evidences on the central and peripheral mechanisms of electrical stimulation in vivo, the purpose of this study was to investigate the influence of afferent stimuli, transcutaneous electrical nerve stimulation and microcurrent, on the electrodiagnostic study of normal subjects.

Electrodiagnostic study was performed before and after the application of afferent stimulion of the right popliteal fossa on 30 healthy female volunteers. After the transcutaneous electrical nerve stimulation, latencies of SEP, H-reflex, and F-wave, and H-amplitude changed significantly(p＜0.01). After the microcurrent stimulation, latencies of SEP, H-reflex, and F-wave, and motor nerve conduction velocity changed significantly(p＜0.01).

The results of this study prove that transcutaneous electrical nerve stimulation and microcurrent may cause changes of the anterior horn excitability and the conduction of the nervous system in vivo. Microcurrent may have a different mechanism of action compared to transcutaneous electrical nerve stimulation by having more localized inhibitory effects on the peripheral nerve. However, further investigation is needed to assess their mechanisms of action and the precise relevance of stimulation parameters.