The Hip – Part Three

We looked at the relevance of a discrepancy in length of leg on the ability to use the hip in a previous article. The leg which is the longer has to stay slightly bent to manage to keep the eyes and head level, preventing the hip from achieving full extension as we take each step. The inability of the hip joint to move back into full extension ensures it has to rotate an amount to achieve the walking pattern required. As an occasional problem this may not be significant, but when multiplied by the thousands of steps we take each day it can develop a painful condition with restriction of joint movement.

If there is a sudden damaging event to the hip such as a strain, jar or a fall the joint can deteriorate rapidly and become much more painful very quickly. This occurs less often however than a gradual onset of pain and stiffness over a longer period of time. A trivial occurrence can set off a joint worsening, beginning with spasm of the local muscles and a loss of the typical range of extension useful in gait. Full extension is the position in which the hip is most tightly fitting and all the surrounding tissues are at their tensest, a position avoided in painful conditions.

A painful hip or other lower limb joint such as a knee is often accompanied by the development of a limp, which is difficult to correct or get rid of when it has been entrenched over some period. The mechanical forces which are transmitted through the hip are significantly altered by a limp, and it changes the actions of the muscles and allows movement restrictions to develop. A steady tightening of the joint capsule can develop and cause loss of hip range of movement. On assessment and treatment of a hip problem a physiotherapist will always correct gait.

The most common degenerative condition in the world’s population is osteoarthritis, which commonly affects the knees and hips. There are many reasons for the onset and progression of osteoarthritis but a history in the family is known to be of some importance. As people get older the occurrence of osteoarthritis rises until in old age virtually everyone has one of more arthritic joints. As the osteoarthritis worsens the joint capsule can tighten up steadily and the healing process in this area is slow due to a low blood supply.

Gradual destruction of the cartilaginous joint lining continues, with some muscle spasm and increasing limp. At some point some arthritic joints deteriorate quickly, perhaps after a trivial traumatic event, and the exact reason for this is not clear, but increased pain and consequent increased muscle spasm may be responsible. Typically hip pain is felt in the lower buttock, the side of the hip, the groin and the front of the thigh. Some patients go to the doctor thinking that they have a thigh or knee problem and end up being diagnosed with hip arthritis.

In the initial stages the x-rays will indicate little of value and the x-ray findings often are not easily correlated with the patient’s disability or pain. As the osteoarthritis worsens joint changes become gradually more apparent such as loss of some of the joint space from cartilage thinning. If severe the head of the femur may become misshapen and osteophytes (bony outgrowths) may occur at the joint margins. In severe arthritis movement and weight bearing may be accompanied by obvious shuddering and grating.

The hip loses its ranges of joint movement typically in a predictable order with the first loss being of extension, the second of abduction (moving the legs apart out to the side) and the last internal joint rotation. On physiotherapy examination an osteoarthritic hip will be positioned forwards and be unable to extend, be laterally rotated so the foot points out and will be kept in close the middle as the outward movement has been lost. The leg shortening and inability to extend the hip during walking can mean that every step involves trunk twisting and the need to go up on tiptoe to some degree to allow for leg shortening.

Jonathan Blood Smyth is the Superintendent of Physiotherapists at an NHS hospital in the South-West of the UK. He writes articles about back pain, neck pain, and injury management. If you are looking for physiotherapists in bradford visit his website.