 As patients walk several times, scientific cameras will record the positions of the reflective balls. Pictures do not involve patients faces or other parts of the body. Afterward, a unique chair system called a Biodex will measure the leg muscle strength. Patients will be asked to sit on the chair and place their leg in a foot in an apparatus, a special structure that measures strength. They will repeatedly push against the apparatus, doing so for 3 seconds. Each time patients push, the researchers will touch a small magnetic device to the skin, which will cause the muscles to push harder. Although this procedure should not cause any discomfort, it may feel unusual. If they wish, patients can ask to stop the test at any time. Few risks are involved in participating in this series of activities. There is a slight chance of mild skin irritation from the adhesives used on the skin or from the soft, rubber-like material. But the material is worn for only a brief period, and skin reactions are rare. Also, that material may feel tight, but if it causes discomfort or prevents moving, patients can ask a researcher to adjust it. There is a slight chance of skin irritation from use of the PD-AFO, but adjustment can be made to make patients comfortable. Patients may experience some muscle soreness caused by participating in the muscle strength tests. However, they will be safely monitored by a physical therapist when they try on the brace to adjust to its feel and fit, as well as during testing of gait. 