Effects of standing on bone density and hip dislocation in children with severe cerebral palsy

Abstract The aim of the study was to evaluate whether standing time associates with bone density and/or hip dislocation in children with severe cerebral palsy. The study design was cross-sectional and descriptive. Eleven boys and seven girls, median age 10.5 years, with severe cerebral palsy participated. Spasticity was measured with modified Ashworth scale. Seven children had scores of 0–1, and 11 had scores of 2–4. Eight of 18 had insulin-like growth factor-I levels lower than −2 standard deviations below the age-matched mean. Time spent in the Standing shell was recorded. Bone mineral density levels determined using dual energy X-ray absorptiometry and hip X-ray were evaluated. Time spent in the Standing shell was 40 min/day (range=4–164). The lumbar spine bone mineral density was 73% of that of age-matched able-bodied controls. Standing time was not associated with bone mineral density, but in 11 children with modified Ashworth scale scores of 2–4, standing time was significantly and negatively associated with hip dislocation. We conclude that time spent in the Standing shell in these 18 children did not affect whole body bone mineral density. In children with spasticity, the association to hip dislocation was significantly negative.