Transcutaneous electrical muscle stimulation has been used to treat spinal curvature. Electrically induced muscle contractions cause partial straightening of the spinal column while the patients sleep. Long-term treatment of 107 patients with progressive idiopathic scoliosis shows a 93% success rate in preventing further progression for curves below 30 degrees while the rate drops to 73% for curves above 30 degrees. In non-idiopathic scoliosis the outcome varied with aetiology and curve magnitude. All kyphosis patients stopped progression.