Effects of passive versus dynamic loading interventions on bone health in children who are nonambulatory.

Purpose: To investigate the effectiveness of a novel dynamic standing intervention compared with a conventional passive standing intervention on bone health in children with cerebral palsy who are nonambulatory.

Methods: Four children in passive standers and 5 in dynamic standers were followed for 15 months (standing 30 min/d, 5 d/wk). Dual-energy x-ray absorptiometry scans of the distal femur were obtained at 3-month intervals to measure changes in bone mineral density (BMD), bone mineral content, and area.

Results: Increases in BMD were observed during dynamic standing (P < .001), whereas passive standing appeared to maintain the baseline BMD. Increases in bone mineral content were observed in each standing intervention (P < .001), with dynamic standing inducing greater increases. Increases in area were comparable between interventions (P = .315).

Conclusions: Dynamic standing demonstrated the potential of moderate-magnitude, low-frequency loading to increase cortical BMD. Further investigations could provide insight into the mechanisms of bone health induced through loading interventions.