Long‐term intensive electrically stimulated cycling by spinal cord–injured people: Effect on muscle properties and their relation to power output

Abstract

Inactivity and muscular adaptations following spinal cord injury (SCI) result in secondary complications such as cardiovascular disease, obesity, and pressure sores. Functional electrically stimulated (FES) cycling can potentially reduce these complications, but previous studies have provided inconsistent results. We studied the effect of intensive long-term FES cycle training on muscle properties in 11 SCI subjects (mean +/- SEM: 41.8 +/- 2.3 years) who had trained for up to 1 hour/day, 5 days/week, for 1 year. Comparative measurements were made in 10 able-bodied (AB) subjects. Quadriceps maximal electrically stimulated torque increased fivefold (n = 5), but remained lower than in AB individuals. Relative force response at 1 HZ decreased, relaxation rate remained unchanged, and fatigue resistance improved significantly. Power output (PO) improved to a lesser extent than quadriceps torque and not to a greater extent than has been reported previously. We need to understand the factors that limit PO in order to maximize the benefits of FES cycling.

The effect of functional electrical stimulation cycling on late functional improvement in patients with chronic incomplete spinal cord injury

“…13,14 In a randomized controlled trial by Johnston et al 15 of pediatric SCI cases, an increase was seen in quadriceps strength with 6 months of FES exercise in comparison with passive cycling and non-cycling electrical stimulation and an increase in quadriceps muscle volume was determined with both FES and noncycling electrical stimulation. Duffel et al 16 reported improvements in quadriceps torque and power output with a 1-year FES cycling exercise program in patients with SCI. In addition to studies assessing the effect of FES cycling on muscle in a laboratory setting, the clinical relevance of this gain in muscle strength and size by FES has also been evaluated by clinical outcomes reflecting functional improvement in SCI.…”

The effects of exercise training on physical capacity, strength, body composition and functional performance among adults with spinal cord injury: a systematic review

“…Most studies prescribed exercise 3 Â per week for 6-12 weeks, although two studies showed particularly large improvements in lower limb power output following 1 year of FES cycling, 3-5 Â per week. 20,21 Unfortunately, it is difficult to pinpoint the exercise intensity required for improvements because the majority of studies (11 of 16) employed FES exercise; stimulation parameters vary widely among these studies and progression typically occurs as individually tolerated. However, moderate-intensity arm ergometry exercise (70-80% max HR or 50% HR reserve) combined with resistance training (progressed to repetitions with 70-80% of the one repetition maximum) seems sufficient for long-term improvements.…”

Functional electrical stimulation as a safe and effective treatment for equine epaxial muscle spasms: Clinical evaluations and histochemical morphometry of mitochondria in muscle biopsies

“…used extensively over several decades as an effective means to reduce or reverse muscle atrophy and to obtain some functional recovery by rehabilitation strategies for spinal cord injury patients, [1][2][3][4][5] including those paraplegics with permanent and complete denervation of the legs (complete Conus and Cauda Equina Syndrome). [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] The benefits of this technology are being expanded into other areas, and FES has been recently utilized for injury rehabilitation and performance enhancement in horses.…”