Idiopathic scoliosis: an electromyographic study.

Thirty-one patients from 12 to 19 years of age having idiopathic scoliosis underwent electromyography of the paraspinal musculature using a Teflon-coated monopolar electrode. The studies conducted with the patients both prone and standing revealed no abnormalities on electrode insertion suggestive of a neuropathic process. In the prone position 29 patients had electrical silence on both the concave and convex side of the curvature. In the standing position most of the patients had asymmetrical activity with a preponderance of activity on the convex side. However, 33% of the patients in whom the spinal musculature was silent in the standing position had balanced curves. This observed correlation between a balanced curve and electrical silence warrants further study.