The cause of a hip labral tear might be:
Trauma. Injury to or dislocation of the hip joint which can occur during car accidents or from playing contact sports such as football or hockey can cause a hip labral tear.
Structural abnormalities. Some people are born with hip problems that can accelerate wear and tear of the joint and eventually cause a hip labral tear.
Repetitive motions. Sports-related and other physical activities including long-distance running and the sudden twisting or pivoting motions common in golf or softball can lead to joint wear and tear that ultimately result in a hip labral tear.