It sounds like your sciatic nerve is acting up. This can occur due to strain on the back. Sciatic nerve pain is usually in the middle of the gluteus and travels down the leg. It can be extremely painful. You can take ibuprofen (Motrin, Advil) for the pain. These meds will help to reduce swelling in the tissue. Use cold packs on the area for about 15 minutes. This will also help to reduce swelling in the area.

If you are in severe pain you may want to see your doctor. A muscle relaxant will help to relax the surrounding muscles. They tense up in response to the pain. A pain medication may help as well.

Back stretches and stretches for the glutes will help. Ask your doctor for a referral to a physical therapist to help you learn specific exercises and stretches.

Hope this helps.