Painful Arc Syndrome is a chronic shoulder pain syndrome resulting from repeated friction and impingement between the structures within the subacromial space and the rostral shoulder arch during shoulder abduction activities, and is a common condition in people over middle age.
It includes subacromial bursitis, supraspinatus tendinitis, supraspinatus tendon calcification, rotator cuff rupture and biceps longus tenosynovitis. The common clinical feature is an arc of pain with active abduction of the shoulder joint, while passive activity is significantly less painful or even completely painless.