Pain arc sign

Pain arc sign is a chronic shoulder pain syndrome caused by repeated friction and impact between the structure under the acromion and the beak and shoulder arch during shoulder abduction. It is a common disease in middle-aged people. The disease includes acromioclavicular bursitis, supraspinatus tendinitis, supramedotitis calcification, rotator cuff rupture, and biceps tendon sheath inflammation. The common clinical feature is that there is a pain arc during active abduction of the shoulder joint, while the pain of passive activity is significantly reduced or even completely painless.