The socket is deepened by the labrum which forms a lip around its rim. Both the ball and socket are lined with articular cartilage which allows frictionless motion between the two.

Arthritis occurs when the cartilage wears. The hip joint is encased in strong ligaments which increases the stability. The iliofemoral ligament is the strongest ligament in the body. The muscles in the hip also play an important role. They allow the 4 movements of the hips – bend, straighten, moving the leg away from the body and bringing it back towards the body.

The muscles found in the hip joint are divided into four groups:

The anterior muscles

located at the front. (this is where the quads are found) – these muscles flex (bend) the thigh at the hip allowing us to sit down or climb a ladder.

The posterior muscles

located at the back. these extend (straighten) the thigh at the hip joint. we rely on strong contractions of this group of muscles to enable us to stand and walk.

The adductor muscles

located on the medial (on inside). this set of groin muscles allow us to move our leg towards the body. this set of muscles can easily be overstretched.

The abductor muscles

located on lateral (or outside). these muscles allow us to move the leg away from the body, for example when doing the splits.

The muscles in the hip

By far the most important group of muscles are the abductor muscles as these are the main pelvic stabilisers when we walk. When these do not function (as in a tear, or secondary to hip joint problems), the patient develops a limp.