Physiological effects of lower extremity functional electrical stimulation in early spinal cord injury: lack of efficacy to prevent bone loss

Abstract

Study design: Controlled, repeat-measures study. Objectives: To determine if functional electrical stimulation (FES) can affect bone atrophy in early spinal cord injury (SCI), and the safety, tolerance and feasibility of this modality in bone loss remediation. Setting: Spinal Injuries Units, Royal Adelaide Hospital and Hampstead Rehabilitation Centre, South Australia. Methods: Patients with acute SCI (ASIA A-D) were allocated to FES (n ¼ 23, 2879 years, C4-T10, 13 Tetra) and control groups (CON, n ¼ 10, 31711 years, C5-T12, four Tetra). The intervention group received discontinuous FES to lower limb muscles (15 min sessions to each leg twice daily, over a 5-day week, for 5 months). Dual energy X-ray absorptiometry (DEXA) measured total body bone mineral density (tbBMD), hip, spine BMD and fat mass (FM) within 3 weeks, and 3 and 6 months postinjury. Results: FES and CON groups' tbBMD differed significantly at 3 months postinjury (Po0.01), but not thereafter. Other DEXA measures (hip, spine BMD, FM) did not differ between groups at any time. No adverse events were identified. Conclusion: Electrically stimulated muscle activation was elicited, and tetanic effects were reproducible; however, there were no convincing trends to suggest that FES can play a clinically relevant role in osteoporosis prevention (or subsequent fracture risk) in the recently injured patient. The lack of an osteogenic response in paralysed extremities to electrically evoked exercise during subacute and rehabilitation/recovery phases cannot be fully explained, and may warrant further evaluation.Spinal Cord (2007) 45, 78-85.

Functional electrical stimulation cycling improves body composition, metabolic and neural factors in persons with spinal cord injury

“…Hjeltnes et al (1997) also found no increase in bone mineral density as a result of 8 weeks of FES cycling in SCI persons, despite a small increase in total body muscle mass. Similarly, no changes in bone mineral density were reported following FES cycling 3 days per week for 6 months (Leeds et al, 1990) or 5 days per week for 5 months (Clark et al, 2007). Increases in bone density have been reported following FES cycling training 5 days per week for 6 months (Belanger et al, 2000) and 3 days per week for 12 months (Mohr et al, 1997).…”

Screening and Habituation of Functional Electrical Stimulation-Leg Cycle Ergometry for Individuals with Spinal Cord Injury: A Pilot Study

“…Previous literature has shown that the knee-joint torques during FES-LCE cycling may be great enough to produce a fracture in the compromised lower limbs of an individual with SCI, 8 and others have been equally conservative in their exclusion of participants due to a history of bone fracture and/or osteoporosis. 8,10,15 …”

Spinal cord injury and physical activity: preservation of the body

“…There is a suggestion of a dose-dependent effect, 70 and the effects disappear if cycling is not sustained. 71 The results of two studies investigating the effects of electrical stimulation applied to the quadriceps with the participant in supine during the first few weeks after injury have yielded different results with respect to prevention of bone loss in the femur. 72,73 Contradictory effects have also been reported for standing training, possibly related to differences in dosage.…”