The common causes of shoulder rotation are subacromial impingement syndrome, osteoarthritis and shoulder joint laxity. 1. Subacromial impingement syndrome: when the shoulder joint carries out rotational movement, the process of impingement between the acromion and the humerus major joint occurs, which will lead to abnormal sound in the joint. 2. Osteoarthritis: due to the loss and wear of articular cartilage, the friction between the joints increases, and there will be bone friction sound during activities, thus there will be staccato sound. 3. Shoulder joint laxity: under the influence of congenital factors, each joint of the whole body appears laxity, humerus and shoulder joint wear and tear impact, easy to produce staccato sound. Caused by the shoulder circle bone on the staccato ring may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor for standardized treatment.