M76: Enthesopathies of lower limb, excluding foot

M76.1: Psoas tendinitis

The iliopsoas muscle consists of 2 parts. These two parts run from the spine and the pelvis to the thigh. The iliopsoas muscle is particularly important in drawing the leg forwards and upwards.

An inflammation in the iliopsoas muscle can affect tendons, tendon sheaths, bursas or joint capsules. Tendons are made up of very firm connective tissue. Tendons attach muscles to bones. A tendon sheath is a covering for the tendon. It cushions the tendon and contains a small amount of fluid. This reduces friction between the tendon and its surroundings. A bursa is a cushion of connective tissue filled with fluid. For example, there is a bursa beneath tendons or between bones and skin. The bursa prevents the tissue from rubbing together. A bursa also enables pressure to be distributed better. Joints are encased in a joint capsule.

An inflammation can be caused by overwork, injuries or pathogens, for example. An inflammation may be painful. The pain may make moving your leg more difficult than usual.