Shoulder pain is more common and bothers many patients, especially middle-aged and elderly patients. Shoulder disorders can no longer be replaced by a general term such as frozen shoulder. Common shoulder disorders can be simply divided into the following categories: 1. Mobility problems including frozen shoulder and post-traumatic shoulder adhesions. It starts slowly with dull pain around the shoulder, which worsens at night and even wakes up with pain. When sleeping, the shoulder often takes a specific lying position because it is afraid of pressure, and it is difficult to turn over and affects sleeping. Gradually, the shoulder becomes difficult to move. Abduction, rotation and posterior extension are the most obvious obstacles. The patient is unable to comb the hair, wash the face, or bathe. The patient has difficulty in carrying dishes and chopsticks and in dressing and lifting pants. The pathology of the disease is contracture of the shoulder capsule, especially of the rostral shoulder ligament. However, the disease is self-limiting, and physical therapy and exercise treatment are available when symptoms are obvious. Post-traumatic shoulder adhesions, with an obvious history of injury, and limited shoulder movement after on, have symptoms similar to frozen shoulder, but less typical than frozen shoulder. 2. Muscle strength problems Include rotator cuff injury and peri-neurogenic injury of the shoulder joint. Rotator cuff injury: Rotator cuff is the tendon tissue inside the shoulder joint, including supraspinatus, infraspinatus, teres minor and subscapularis. The main manifestation is recurrent or continuous shoulder joint pain, which is aggravated at night and cannot sleep to the affected side. In young people, it is caused by sports injuries, such as throwing movements and overhead racket swinging, and is more common in volleyball, gymnastics, and swimming athletes; in middle-aged and elderly people, it is often caused by rotator cuff metaplasia and brittle texture. It is easy to confuse this disease with frozen shoulder clinically. However, the motor dysfunction of this disease is different from that of frozen shoulder in that the abductor and pronator muscles are reduced in strength and joint movement is limited, but the active mobility is mainly limited, while the passive mobility is often greater than the active mobility. Periprosthetic nerve injury , with related history, MRI and electromyography usually have more positive indicators. 3. Stability problems mainly include congenital multiple joint laxity and traumatic anterior instability of the shoulder joint. Congenital multiple joint laxity is mainly manifested by increased mobility of multiple joints, and instability of the shoulder joint is mostly multidirectional. In traumatic anterior shoulder instability, the initial dislocation usually has a history of shoulder trauma, and the second dislocation usually has no obvious trauma, some patients may have as many as several or dozens of dislocations, and some patients can reset themselves. Some patients may have several or dozens of dislocations, and some patients may reset themselves. These patients are generally afraid of the abduction and external rotation of the shoulder joint. 4. Smooth joint problems include subacromial impingement syndrome and degenerative joint disease. Subacromial impingement syndrome: It is one of the main causes of chronic shoulder pain and is caused by the rotator cuff tissue impinging on the front 1/3 of the rotator cuff, which is mainly concentrated in the supraspinatus muscle attached to the greater tuberosity of the humerus. The clinical symptoms caused, including shoulder pain, and the nature of the pain are difficult to distinguish from other shoulder disorders. However, most of the active shoulder movements are not affected in this disease, except for the pain that can be significantly induced when the shoulder is lifted forward. Degenerative joint diseases, both primary and secondary, are included.