Stochastically-modulated stimulation to slow down muscle fatigue at stimulated sites in paraplegics using functional electrical stimulation for leg extension

• Published in: Neurological research (New York) Vol. 22; no. 7; p. 703
• Main Authors: Graupe, D, Suliga, P, Prudian, C, Kohn, K H
• Format: Journal Article
• Language: English
• Published: England 01.10.2000
• Subjects: Electric Stimulation Therapy - methods; Humans; Leg; Muscle Fatigue; Paraplegia - therapy; Spinal Cord Injuries - therapy; Thoracic Vertebrae
• ISSN: 0161-6412
• DOI: 10.1080/01616412.2000.11740743

This short communication is a preliminary report on a study concerning slowing down the rate of muscle fatigue when FES (Functional Electrical Stimulation) is applied for standing and walking by complete (traumatic) thoracic-level paraplegics. It is shown that randomly modulating the inter-pulse interval between FES pulses (which serve to trigger action potentials in the peripheral nerves concerned) results in a significantly lower rate of muscle fatigue, as tested in a series of leg extensions, when FES was applied at the quadriceps. Specifically, we report that the best results (longest durations of leg extension prior to onset of muscle-fatigue) were achieved with a +/- 5 msec uniformly-distributed (pseudo-) white-noise modulation at a 42 msec inter-pulse interval (24 pulses per sec). These resulted in an average increase in duration of leg extension of approximately 37% in this pilot study, as compared with unmodulated (fixed-rate) trains of FES pulses. This significant increase, even in a very preliminary study appears to merit careful further examination, since it may allow a possibly significant increase in standing duration and in walking range of paraplegics using FES for ambulation.