M75: Shoulder lesions

M75.4: Impingement syndrome of shoulder

The acromion is a bony protrusion at the top of the shoulder blade. The acromion can be felt as a small bump on top of the shoulder. Various muscles and tendons run beneath the acromion. These muscles enable the arm to be lifted, for example.

The space below the top of your shoulder blade can become narrower than usual due to wear and tear or after an injury, for example. Then tissue such as muscles or tendons can become pinched.

When tissue beneath the top of the shoulder blade gets pinched, it can be painful. It may then be particularly painful when you raise your arm or lie on the affected side.