In a surgical procedure electrodes are inserted into muscles of the lower extremities to correct hip, knee and ankle function. The electrode leads are connected to an implanted pulse generator located in the abdomen. After a typical post-operative period of two to five days, the recipient will be discharged home for two to six weeks of moderate activity. Following a 6 week period of laboratory exercise and training, functional use of the neuroprosthesis will begin at home and in the community with follow-up evaluations at 1, 3, 6 and 12 months. Laboratory assessments include walking speed and distance, physiologic cost, muscle strength, measure of spasticity, and gait analysis with and without stimulation. A number of self-reporting instruments are administered to capture individual's participation, quality of life and various aspects of perceived community ambulation.