Hello, You have been diagnosed by inflamed S1 joint. Presently you get shooting pain down your leg and lower back. You are suggested to get treated the cause of inflammation. If it is due to some wrong position or activity, you will have to get control over it. Avoid sitting for a long time, change posture, sit on a doughnut pillow or doughnut ring to hurt less. Avoid heavy physical activity or take help to avoid stress on the inflamed S1, avoid activities like fast long walking, running, etc., that may cause hypermobility in your pelvis. Pain is worsened by weight bearing activity, avoid it. Give a little rest to your pelvis. Physical therapy is advisable only after inflammation & pain reduce, not now. You can consult a Physical therapist for relaxation techniques, relaxation will help. Heat therapy, NSAIDS, S1 joint steroid injections, supports or braces are helpful. Maintain proper posture while sitting, standing or sleeping. Get treated at the earliest. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician