Hip Osteoarthritis And Its Related Postural Habits

The previous article touched upon hip osteoarthritis and muscles which may be weak and strong allowing for more specific rehabilitation.

In addition to muscle imbalance, are there particular postures that a person adopts that aggravates the disease process?

Osteoarthritis can affect all joints. There has been much written regarding arthritic knees. The same, however, cannot be said for hip osteoarthritis.

The purpose of this article aims to briefly discuss hip osteoarthritis, and associated postures that may progress the disease process.

Hip Anatomy

The hip joint consists of the articulating surfaces between the symmetrical socket known as the acetabulum (of the pelvis), and the femur (thigh bone). The labrum – a cartilage-covered ring of fibrocartilage – deepens the acetabulum. It is to aid in the congruency of the joint. The joint space between the acetabulum and femur are at equal points throughout, to allow adequate lubrication.

The hip joint relies heavily on the surrounding capsule, ligaments (transverse, iliofemoral, pubofemoral, and ischiofemoral ligaments) and muscles to maintain it stability.

What Is Hip Osteoarthritis?

It is a condition that affects the cartilage surrounding the joint. Thus, it exposes the bone; reducing the joint space and allowing for bone and bone contact. Hip osteoarthritis is something that affects people more commonly over the age of 50. Obesity, previous hip fractures, congenital conditions and genetic predispositions worsens it.

Symptoms of Hip Osteoarthritis

Arthritic hips can be very varied and transient depending on factors such as a weather. Main symptoms include:

• Pain with weight bearing activities
• Limited range of motion
• Stiffness of the hip
• Walking with a limp
• Referred pain at the bottom and groin

Postural Habits

A patient will tend to stand in a way they deem is “good posture” for the assessing therapist in a clinical setting. This is all well and good and provides the therapist an idea of that patient’s perception and awareness of posture. However, another important consideration is what posture that patient assumes during prolonged standing, and in relaxed postures in their normal environment.

“Hanging On The Hips”

When looking at the hip joint, one must consider negative postures. An example of this is the “hanging on the hips”. The weight is shifted to one side (e.g the right), and the opposing pelvis (i.e the left) is dropped down into relative adduction in this posture. The adductors on the left will be stretched (lengthened) if this hip (left) is in increased adduction (shortened adductors). This is because the muscles work in pairs and as opposites.

Also in such stances, the iliotibial tract band (ITB) is in tension and muscle activity on the left is reduced. These are postures that are often observed by clinicians when assessing the single leg stance of patient with hip osteoarthritis.

Such a pose may lead to a phenomenon termed ‘stretch weakness’ occurring in the hip adductor muscles on the left. As a result of the lengthening of hip adductors, it causes inner range weakness.

As such, ‘hanging on the hip’ in adduction overtime may actually lead to physiological changes, making the muscle weaker. Testing and strengthening hip adductors are to be done with the leg in adduction (10 degrees) and in neutral. This is to gain the most therapeutic benefit for osteoarthritic patients.

What The Research Says

Interestingly there has been research suggesting that weight bearing with excessive hip adduction will also result in increased joint forces and this had been found in patients with early hip joint pathology during the stance phase of gait; further highlighting the importance to reduce adduction and increase adduction strength.

In addition to increasing the load through the joint, excessive hip adduction also has the effect of increasing the compressive load of the ITB over the greater trochanter, into which the glut. medius tendon inserts. Therefore prolonged standing in the “hanging on the hips” posture produces a significant amount of compressive loading of the glut. medius tendon and therefore possible dysfunction.

Other Negative Postural Habits

Sitting cross-legged in hip adduction, and sleeping in sidelying in hip are other negative postures that produce the above effects. Patients with occupations requiring prolonged standing should receive proper advice and rehabilitation.

Treatment For Hip Osteoarthritis

Treatment for such clients should not only look at strengthening the adductor muscles at different ranges, as already discussed but also to educate the patient about these postures to avoid lengthening the adductors and compressive loading of the ITB and gluteus medius tendon.

References:

Grimaldi, A (2009)Assessing lateral stability of the hip and pelvis, Physiotec Physiotherapy, Manual Therapy:16 (2011) 26-32