The hip is a “ball-and-socket” joint. The largest bone in the body, the femur, is in the thigh and narrows to a “neck” that angles into the pelvis and ends in a ball-shaped knob. This ball fits into a curved socket in the pelvic bone (acetabulum). This arrangement provides a joint that can move freely in all directions. The joint itself is located rather deep under some big muscles so that it is protected from dislocating – that is, from coming out of the socket.



Two special problems arise because of this anatomical arrangement. The narrow neck of the femur can break rather easily, and this is usually what happens when an older person “breaks a hip” after a slight fall. Also, the “ball” part of the joint must get its blood supply from below, and the small artery that supplies the head of the femur can become clogged, leading to death of the bone and a kind of arthritis called aseptic necrosis.

The hip joint can also become infected. Very occasionally it will be the site for an attack of gout. The bursae that lie over the joint can be inflamed with bursitis. Rheumatoid arthritis can injure the joint. Conditions such as spondylitis can cause stiffness or loss of motion of the hip.

A “flexion contracture” is a common consequence of hip problems. This means that motion of the hip joint has been partly lost. The hip becomes partially fixed in a slightly bent position. This causes the pelvis to tilt forward when you walk or stand, so that when you stand straight the back has to curve a little more than normal. This allows extra strain on the low back area.

For poorly understood reasons, pain in the hip is often felt down the leg, often at or just above the knee. This is called “referred” pain. Non-referred hip pain may be felt in the groin or the upper outer thigh. Pain that starts in the low back is often felt in the region of the hip. Since the hip joint is so deeply located, it can often be troublesome to locate the exact source of pain in these regions.

Listen for the pain message and try to avoid activities that are painful or that aggravate pain. You will want to avoid pain medication as much as possible. Rest the joint from painful activities. Use a cane or crutches if necessary. The cane is usually best held in the hand opposite the painful hip since this allows greater relaxation in the large muscles around the sore hip joint. Move the cane and the affected side simultaneously, then the good side.

As the pain begins to resolve exercise should be gradually introduced. First, use gentle motion exercises to free the hip and prevent stiffness. Stand with your good hip by a table and lean on the table with your hand. Let the bad hip swing to and fro and front and back. Lie on your back with your body half off the bed and the bad hip hanging and let the leg stretch backward toward the floor. Standing, see how far apart you can straddle your legs and bend the upper body from side to side. With your feet together, try to turn your feet apart like a duck so that the rotation ligaments are stretched. Repeat these exercises gently two or three times a day.

Then introduce more active exercises to strengthen the muscles around the hips. Lie on your back and raise your legs one at a time. Bicycle or walk. When walking, start with short strides and gradually lengthen them as you loosen up. Gradually increase your effort and distance, but not by more than 10% each day. Swimming stretches muscles and builds good muscle tone.

A good firm bed will help, and the best sleeping position is on your back. Avoid pillows beneath the knees or under the low back. Make sure you are taking anti-inflammatory medication as prescribed, especially if you have rheumatoid arthritis or spondylitis.