A randomised controlled trial of standing programme on bone mineral density in non-ambulant children with cerebral palsy

Background: Severely disabled children with cerebral palsy (CP) are prone to low trauma fractures, which are associated with reduced bone mineral density. Aims: To determine whether participation in 50% longer periods of standing ( in either upright or semiprone standing frames) would lead to an increase in the vertebral and proximal tibial volumetric trabecular bone mineral density (vTBMD) of non-ambulant children with CP. Methods: A heterogeneous group of 26 pre-pubertal children with CP ( 14 boys, 12 girls; age 4.3-10.8 years) participated in this randomised controlled trial. Subjects were matched into pairs using baseline vertebral vTBMD standard deviation scores. Children within the pairs were randomly allocated to either intervention ( 50% increase in the regular standing duration) or control ( no increase in the regular standing duration) groups. Pre- and post-trial vertebral and proximal tibial vTBMD was measured by quantitative computed tomography (QCT). Results: The median standing duration was 80.5% (9.5 - 102%) and 140.6% ( 108.7 - 152.2%) of the baseline standing duration in the control group and intervention group respectively. The mean vertebral vTBMD in the intervention group showed an increase of 8.16 mg/cm(3) representing a 6% mean increase in vertebral vTBMD. No change was observed in the mean proximal tibial vTBMD. Conclusion: A longer period of standing in non-ambulant children with CP improves vertebral but not proximal tibial vTBMD. Such an intervention might reduce the risk of vertebral fractures but is unlikely to reduce the risk of lower limb fractures in children with CP.