Piriformis syndrome is a rare disorder of the nerves and muscles. When you have it, your piriformis muscle--a flat, band-like muscle located in your butt near the top of your hip joint--presses on the ...

You may have heard of sciatica, a pain that starts in the buttocks and runs down one or both legs. Sciatica is usually caused by pressure or irritation of nerves in the lower back. One condition that ...