The muscle that can cause pain in your buttocks, back and knees
Deep in the buttocks, there is a muscle that can cause more problems than you ever imagined. It is your piriformis muscle; it is located behind the hip cavity on each side of your body.
Its function is to help rotate and flex your legs while you walk, balancing and doing practically anything else that involves the lower part of your body.
When the piriformis muscle becomes inflamed, either on one or both sides, it triggers a pain in the back of the body, and also in the back, hips, legs and knees.