Can FES-rowing mediate bone mineral density in SCI: a pilot study

Abstract

Study design: A single case study. Objectives: To compare proximal tibia trabecular bone mineral density (BMD) of a participant with complete spinal cord injury (SCI), long-termed functional electrical stimulation-rowing (FES-R) trained, with previously reported SCI and non-SCI group norms. To estimate lower limb joint contact forces (JCFs) in the FES-R trained participant. Setting: UK University and orthopaedic hospital research centre. Methods: Bilateral proximal tibial trabecular BMD of the FES-R trained participant was measured using peripheral quantitative computerised tomography, and the data were compared with SCI and non-SCI groups. An instrumented four-channel FES-R system was used to measure the lower limb JCFs in the FES-R trained participant. Results: Structurally, proximal tibial trabecular BMD was higher in the FES-R trained participant compared with the SCI group, but was less than the non-SCI group. Furthermore, left (184.7 mg cm À3 ) and right (160.7 mg cm À3 ) BMD were well above the threshold associated with non-traumatic fracture. The knee JCFs were above the threshold known to mediate BMD in SCI, but below threshold at the hip and ankle. Conclusion: As pathological fractures predominate in the distal femur and proximal tibia in chronic SCI patients, the fact that the FES-R trained participant's knee JCFs were above those known to partially prevent bone loss, suggests that FES-R training may provide therapeutic benefit. Although the elevated bilateral proximal tibial BMD of the FES-R participant provides circumstantial evidence of osteogenesis, this single case precludes any statement on the clinical significance. Further investigations are required involving larger numbers and additional channels of FES to increase loading at the hip and ankle. Spinal Cord (2014) 52, S4-S5; doi:10.1038/sc.2014.112 INTRODUCTIONOsteoporosis is a known secondary complication of spinal cord injury (SCI) characterised by low bone mineral density (BMD), which results in a high incidence of pathological fractures in the distal femur and proximal tibia. 1 Physical therapy is one strategy under investigation to mediate bone loss in SCI by increasing muscle-induced skeletal loading. 2 In the SCI model, functional electrical stimulation (FES) is required to activate paralysed muscle. Although the dose-response in the SCI model is unknown, compressive loads of 1-2 times body weight, delivered by FES-induced muscle contractions, have been found to partially prevent bone loss after SCI. 2 The aims of this study were to: (1) compare the lower limb BMD of a participant with long-term FESrowing (FES-R) trained with SCI and non-SCI groups, using peripheral quantitative computerised tomography imaging and (2) establish the magnitude of joint contact forces (JCFs) in the lower limbs of the FES-R trained participant. MATERIALS AND METHODSThe participant for these trials (Table 1), and author of this paper, had been FES-R trained for 48 years as described in reference 3 using quadriceps and hamstring controlled FES-activation. Th...

FES-rowing attenuates bone loss following spinal cord injury as assessed by HR-pQCT

“…Gibbons et al 8 recently reported the potential to modulate bone loss in a male, age of 59 years with a T4 complete SCI following a road traffic accident, who is highly trained (412 years) in FES-rowing. The individual was 14 years post injury, with no history of musculoskeletal complications or medications known to affect bone (calcium, vitamin D or antiresorptive drugs).…”

“…Although lower limb spasticity has increased since this individual's injury, daily FES-assisted exercise and passive standing successfully manages the condition without the need for anti-spasmodic medications. In Gibbons et al 8 bilateral trabecular bone density in the proximal tibia was reported using peripheral quantitative computed tomography (Stratec XCT3000, Pforzheim, Germany). The FES-rower's bone metrics were compared with data from a previous study involving a non-SCI cohort (n = 14; mean age of 37 years) and a cohort of chronic SCI who were FES-untrained (n = 9; mean age of 32 years; mean of 6.6 years post injury).…”

“…7 One such intervention under investigation is functional electrical stimulation (FES) rowing. 8 In the present configuration, FES-rowing is an exercise that combines voluntary upper-limb concurrent with FESassisted lower-limb exercise involving the quadriceps, hamstrings, tibialis anterior and triceps surae musculature. The training program, which involves three 30-min FES-rowing sessions and four 60-min FES-activated knee extension exercise sessions per week, has been previously described in detail.…”

FES-rowing in tetraplegia: a preliminary report

“…Furthermore, it is highly likely that muscle strength also increased in line with the increases in average and peak POs. 27 These hypotheses require further investigation with measures of metabolic cost and skeletal loading during and following FES-R training.…”

“…However, large variability exists in the volume and type of training sessions required to enable individuals to continuously FES-row for 30 min. Future research should focus on the impact of increasing the number of muscle groups stimulated, and whether this results in the modification of cardiovascular disease risk factors and improvement in skeletal loading 27 in people with SCI following FESrowing training.…”