Effect of adjusting pulse durations of functional electrical stimulationcycling on energy expenditure and fatigue after spinal cord injury

摘要

The purpose of the current study was to determinethe effects of three different pulse durations (200, 350, and 500microseconds [P200, P350, and P500, respectively]) on oxygenuptake, cycling performance, and energy expenditure (EE) percentageof fatigue of the knee extensor muscle group immediatelyand 48 to 72 h after cycling in persons with spinal cordinjury (SCI). A convenience sample of 10 individuals withmotor complete SCI participated in a repeatedmeasures designusing a functional electrical stimulation (FES) cycle ergometerover a 3 wk period. There was no difference among the threeFES protocols on relative oxygen uptake or cycling EE. DeltaEE between exercise and rest was 42% greater in both P500 andP350 than in P200 (p = 0.07), whereas recovery oxygen uptakewas 23% greater in P350 than in P200 (p = 0.03). There was nodifference in the outcomes of the three pulse durations on musclefatigue. Knee extensor torque significantly decreased immediatelyafter (p < 0.001) and 48 to 72 h after (p < 0.001) FES legcycling. Lengthening pulse duration did not affect submaximalor relative oxygen uptake or EE, total EE, and time to fatigue.Greater recovery oxygen updake and delta EE were noted inP350 and P500 compared with P200. An acute bout of FES legcycling resulted in torque reduction that did not fully recover 48to 72 h after cycling