The use of muscle stimulation for inducing scoliotic curves. A preliminary report.

Based on a clarification of the anatomical mechanisms involved in the lateral stability of the spine, electrical stimulation was applied unilaterally to paraspinal muscles of 20 growing dogs in an attempt to produce thoracic scoliotic curves. These experiments were considered critical in the development of a new procedure for correcting human scoliosis. Various alternating voltages and wave forms were used. The curvature varied with the voltage applied, frequency being maintained at a constant value. Curves can be developed in the spines of normal dogs by unilateral electronic muscle stimulation without clinical discomfort or significant muscle atrophy. Curves always develop in the predicted direction (concave to stimulation). Stimulation of more than 4-6 weeks produced curves with significant wedging and rotational deformation. In one experiment curves created in one direction were reversed by stimulating opposite side musculature. Because of the similarity of human and canine anatomy, the results obtained gave impetus to further experimentation with human application. Electromyographic tests, biopsy studies, direct deformation measurements of post mortem dissections and weekly X-rays substantiate the above observations.