High-volume FES-cycling partially reverses bone loss in people with chronic spinal cord injury

After 12 months of FES-cycling, trabecular and total bone mineral density (BMD) as well as total cross-sectional area in the distal femoral epiphysis increased significantly by 14.4 ± 21.1%, 7.0 ± 10.8% and 1.2 ± 1.5%, respectively. Bone parameters in the femoral shaft showed small but significant decreases, with a reduction of 0.4 ± 0.4% in cortical BMD, 1.8 ± 3.0% in bone mineral content, and 1.5 ± 2.1% in cortical thickness. These decreases mainly occurred between t1 and t2. No significant changes were found in any of the measured bone parameters in the tibia. Muscle CSA at the thigh increased significantly by 35.5 ± 18.3%, while fat CSA at the shank decreased by 16.7 ± 12.3%. Our results indicate that high-volume FES-cycle training leads to site-specific skeletal changes in the paralysed limbs, with an increase in bone parameters at the actively loaded distal femur but not the passively loaded tibia. Thus, we conclude that high-volume FES-induced cycle training has clinical relevance as it can partially reverse bone loss and thus may reduce fracture risk at this fracture prone site.