Participants will fill out a packet of questionnaires about their pain, health, and quality of life at three intervals: when they enroll in the study, at the end of treatment, and 12 weeks after treatment ends. At these same time intervals, patients will come to NIH for a test of their physical ability to walk and climb stairs. Patients will keep a diary and pain symptoms and medications for 1 week before treatment begins and 1 week after it ends, and will fill out questionnaires about pain during the entire study period.