Stochastically-modulated stimulation to slow down muscle fatigue at stimulated sites in paraplegics using functional electrical stimulation for leg extension.
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.
Graupe
D
D
University of Illinois, Chicago 60607, USA.
Suliga
P
P
Prudian
C
C
Kohn
K H
KH
D004599:Electric Stimulation Therapy / Q000379:methods*; D006801:Humans; D007866:Leg; D018763:Muscle Fatigue; D010264:Paraplegia / Q000628:therapy*; D013119:Spinal Cord Injuries / Q000628:therapy*; D013904:Thoracic Vertebrae