The effect of low-magnitude whole body vibration on bone density and microstructure in men and women with chronic motor complete paraplegia

Objective: To examine the effect of low-magnitude whole body vibration on bone density and microstructure in women and men with chronic motor complete paraplegia. Methods: We studied nine subjects (four women and five men) with motor complete paraplegia of 2 years duration or more, age 20-50 years. Subjects were instructed to stand on a low-magnitude vibration plate within a standing frame for 20 minutes per day, 5 days a week, and for 6 months. Bone density at the proximal femur by dual-energy X-ray absorptiometry and bone microstructure at the distal tibia by highresolution peripheral quantitative computed tomography were assessed at four timepoints over 12 months (baseline, at 3 months and 6 months while on intervention, and after 6 months off intervention). Results: Standing on the low-magnitude vibration plate with a standing frame was well tolerated by participants. However, most subjects did not show an improvement in bone density or microstructure after 6 months of intervention, or any relevant changes 6 months following the discontinuation of the low-magnitude vibration. Conclusion: We were unable to identify an improvement in either bone density or microstructure following 6 months use of a low-magnitude vibration plate in women or men with chronic motor complete paraplegia. Longer duration of use may be necessary, or it is possible that this intervention is of limited benefit following chronic spinal cord injury.