Femoroacetabular impingement (FAI)
Femoroacetabular impingement (FAI), is a situation where the ball and socket do not move completely by their normal range of movement. This might be because the top of the ball is not round completely or because the socket is quite deep. It is not completely understood why this occurs, and in many cases, no special treatment is required. In a few cases, surgery might enhance the movement range in the hip, but still, it is not clear whether this aids in preventing arthritis from forming in the long term.
If scans and x-rays of the hip joint are normal, then their symptoms might lead to referred pain in your back. Pain occurs from a problem with your lower back that might only feel in your buttocks, down the back of your legs by the outer side of your hip joint, and mostly in the front of your hip.