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

• Published in: Muscle & nerve 2008-10, Vol.38 (4), p.1304-1311
• Main Authors: Duffell, Lynsey D., Donaldson, Nick de N., Perkins, Tim A., Rushton, David N., Hunt, Kenneth J., Kakebeeke, Tanja H., Newham, Di J.
• Format: Article
• Language: English
• Subjects: Adult; Bicycling - physiology; Biological and medical sciences; Electric Stimulation Therapy - methods; Exercise Therapy - methods; Exercise Tolerance - physiology; Female; FES cycling; Fundamental and applied biological sciences. Psychology; Humans; Male; maximal torque; Medical sciences; Metabolic diseases; Middle Aged; Muscle Contraction - physiology; Muscle Fatigue - physiology; Muscle Strength - physiology; Muscle Weakness - etiology; Muscle Weakness - physiopathology; Muscle Weakness - therapy; Muscle, Skeletal - innervation; Muscle, Skeletal - physiopathology; Muscular Atrophy - physiopathology; Muscular Atrophy - therapy; Obesity; Paralysis - etiology; Paralysis - physiopathology; Paralysis - therapy; power output; Quadriceps Muscle - innervation; Quadriceps Muscle - physiopathology; Recovery of Function - physiology; skeletal muscle; Spinal Cord Injuries - therapy; spinal cord injury; Striated muscle. Tendons; Time; Time Factors; Treatment Outcome; Vertebrates: osteoarticular system, musculoskeletal system
• ISSN: 0148-639X; 1097-4598
• DOI: 10.1002/mus.21060

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. Muscle Nerve 38: 1304–1311, 2008