Efficacy of home-based virtual cycling training on bone mineral density in ambulatory children with cerebral palsy

Summary: The 12-week home-based virtual cycling training (hVCT) improved lower limb muscle strength and areal bone mineral density (aBMD) than the control program in children with cerebral palsy (CP). A muscle strengthening program, rather than general physical activity, is more specific in enhancing aBMD for these children. A novel hVCT is an effective and efficient strategy that enhances lower limb bone density in these children. Introduction: This is the first study to assess the efficacy of a novel hVCT program on bone density for children with spastic CP using a well-designed randomized controlled trial. Methods: Twenty-seven ambulatory children with spastic CP, aged 6-12 years, were randomly assigned to the hVCT group (n = 13) or control group (n = 14). Outcome measures - motor function [Gross Motor Function Measure-66 (GMFM-66)], muscle strength (curl up scores and isokinetic torque of knee extensor and flexor muscle) and aBMD of the lumbar and distal femur - were administered before and immediately after the 12-week intervention. Results: Analysis of covariance results show that the hVCT group had greater distal femur aBMD and isokinetic torques of knee extensor and flexor muscles than the control group at posttreatment (p < 0.05). However, curl up scores, GMFM-66, and lumbar aBMD at posttreatment did not differ between the two groups. Conclusions: Analytical findings suggest that the muscle strengthening program is more specific in enhancing bone density for children with CP than general physical activity. Thus, the proposed 12-week hVCT protocol is an effective and efficient strategy for improving lower limb aBMD in these children.