The primary function of the hip is to support the weight of the body when we walk, run or stand.
Like the shoulder, the hip is a ball and socket joint in which the ball of one bone (the femur) fits into the socket of another (the pelvic bone).
As the most flexible joint in the body, the normal hip can move backwards and forwards, from side-to-side, and can perform twisting motions. The hip also contains a small amount of fluid, which lubricates the joint whenever you move it.
There are more than 20 muscles that cross the hip joint, and any one of those muscles can get injured and masquerade as hip pain.
Other structures in the hip that can be injured or diseased include the bursa, labrum, ligaments, tendons, cartilage and bone.
People with hip problems often complain of pain in their groin that can radiate to their thighs or knees. Pain on the backside of the hip or along the buttock often comes from lower back problems and is sometimes mistaken as hip pain.
Common hip problems include muscle pulls or strains, bursitis and labral tears. These can occur due to trauma, athletics, or as the result of overuse at work.
Arthritis of the hip is another common cause of hip pain, especially as we age. There are several conditions that can lead to hip arthritis, including osteonecrosis and genetic abnormalities.
Osteonecrosis of the femoral head – the “ball” portion of the hip – occurs when there is an interruption of the blood supply to the head. As a result, the top of the head collapses and loses its round shape, which can predispose it to early arthritis.
It’s also possible to have childhood diseases or even be born with abnormalities of the hip that can lead to early arthritis. Malformations of the hips can put abnormal forces across an otherwise normal hip joint and predispose it for earlier wear and tear.
Genetics plays a strong role in the development of arthritis as well, particularly when it occurs in multiple joints and at a younger age.