Trunk muscle activities in braced scoliosis patients.

There are two theories as to why bracing may prevent the progression of idiopathic scoliosis curves, the passive and the active theories. The passive theory is that progression is prevented by the forces exerted by the brace. The active theory is that progression is prevented by muscle contractions that arise in response to wearing the brace. This study examined the active theory of brace correction. Trunk muscle myoelectric activities were measured in ten adolescent females with right thoracic idiopathic scoliosis being treated with Boston braces. Activities were both measured when wearing and when not wearing their braces. Differences in braced and unbraced myoelectric activities were seldom statistically significant and never biomechanically significant. Boston brace effectiveness seems not to result from active responses to brace wearing.