The cause of overuse lesions is not fully understood. Micro-lesions leading to degenerative changes or to chronic inflammation have been suggested. The lesion can be located in the muscle, the tendon, or the enthesis. The changes seen in the pubic bone and around the pubic symphysis probably reflect the amount of stress inflicted by the sport or activity involved, although these changes are not a definite sign of pathology but rather a sign of a repair reaction. In the hip joint, femoroacetabular impingement (FAI) can be caused by a variety of dysplasia especially related to the acetabulum, and by the so-called cam lesion, which is perhaps inflicted in puberty by excessive loads from sport. FAI and other types of trauma or overuse can lead to intra-articular lesions of the labrum, cartilage, or the ligamentum teres.