 With this training, patients may return several times to learn how to walk with the brace, but for their protection, they will not be allowed to take it or use it outside the research teams supervision. The researchers will examine the leg to ensure that the brace fits and will ask questions about it. Each training visit will require up to 1.5 hours. When patients have learned to walk with the brace, they will be asked to visit again and walk while scientific pictures are taken of their legs. During the walking test, patients will wear T-shirts and shorts. Patients arms and legs will be wrapped with a soft, rubber-like material, to allow small plastic reflective balls to be attached. Firm material known as a shell can be attached to the rubber sleeves, with Velcro or a self-sticking bandage. The small balls may also be attached to the skin, with an adhesive. Also, there may be a test of the muscles, through the use of electromyography, or EMG. The test involves attachment of small metal electrodes to the surface of the skin, again with an adhesive. There should not be discomfort with that test. 