Subacromial impingement – also called shoulder impingement – is a painful condition that develops when the shoulder tendons or bursa (a cushion that prevents rubbing and irritation of the tissues) get pinched during movement of the shoulder.
It is a common cause of shoulder pain. It can lead to inflammation of the rotator cuff tendons (tendinitis) and bursa (bursitis). Pain can also come directly from these tendons due to inflammation or degeneration without physical catching or impingement. This is sometimes called subacromial pain syndrome.