Frozen shoulder is an adhesive capsulitis that causes stiffness of the glenohumeral joint. It is characterized by pain around the shoulder joint, reduced active and passive mobility in all directions of the shoulder joint, and no significant abnormalities on imaging except for a decrease in bone mass. It is also known as frozen shoulder. Incidence: left side is higher than right side, only 8% are affected bilaterally. Age of onset: 40-60 years old. The pathogenesis of frozen shoulder has the following three characteristics: ① the soft tissues around the joint capsule are eventually invaded; ② the development of lesions is not uniform, not all tissues have the same pathological changes; ③ the progression of pathological changes is reversible. By grasping the above pathological changes and the three characteristics, we have a deeper understanding of frozen shoulder, and it is easier to understand the process of changes in the clinical symptoms of frozen shoulder. The entire course of frozen shoulder can be divided into three phases: the beginning phase, the freezing phase, and the thawing phase. The beginning phase is characterized by an uncomfortable and binding sensation in the shoulder joint. The pain may be limited to the anterolateral aspect of the shoulder joint, or may extend to the point of resistance of the deltoid muscle. The shoulder joint gradually becomes stiff and painful. The pain during the freezing phase can be mild or severe, and is characterized by increased pain at night which affects the patient’s sleep. When the shoulder joint is moved, it can cause strong pain and muscle spasm, so that the movement of the shoulder joint can be completely restricted, as if the hand is frozen. The pain is very mild during the thawing phase, the shoulder joint starts to relax gradually and the glenohumeral joint gradually regains more movement. some individual patients only partially recover the function of the shoulder joint or are tonic and unable to move. x-ray shoulder examination may show no abnormalities or only osteoporosis of the humeral head. Blood sedimentation, anti-chain “O” and latex tests are negative. Diagnostic criteria There are no strict unified diagnostic criteria for frozen shoulder. The recommended criteria are: passive abduction <100° (60%) 2. external rotation <50° (55%) 3. internal rotation <70° (75%) 4. anterior elevation <140° (80%) or: progressive shoulder pain with decreased mobility, and frozen shoulder can be diagnosed when other etiologies are excluded. 1. Middle-aged and elderly people aged 40 to 50 years or older, often with a history of rheumatic cold attack or trauma. It is more common in women and is commonly referred to as the "50th shoulder". 2. Pain in the shoulder and painful activity, which can be radiated to the hand, but no abnormal sensation. 3. Shoulder joint activity is especially limited by supination, abduction, internal and external rotation. 4. Pressure pain around the shoulder, especially in the long head tendon groove of the biceps. 5.Spasm or atrophy of the muscles around the shoulder. 6.X-ray and laboratory examination usually have no abnormal findings. Differential diagnosis A complete shoulder movement is mainly accomplished by four joints, namely the glenohumeral joint, acromioclavicular joint, sternoclavicular joint and scapulothoracic wall joint, while frozen shoulder mainly occurs in the glenohumeral joint. Frozen shoulder rarely develops twice in one shoulder joint. The age of onset of frozen shoulder corresponds to the age at which severe degeneration of the shoulder joint occurs. Weaker individuals, such as those with metabolic diseases, malnutrition, heart disease, and menopausal syndrome, experience more shoulder degeneration than healthy individuals and are therefore more susceptible to this disease. Patients usually have no history of trauma, or have a very minor trauma to the shoulder or upper arm, and gradually the shoulder joint and its surrounding muscles become painful, weak, and impaired in movement. Pain is the most obvious symptom and has a persistent nature. It can be spontaneously aggravated at night and interfere with sleep. The pain can cause persistent muscle spasm, which can be mild or severe. The pain and muscle spasm can be confined to the shoulder joint, but can also radiate upward to the back of the head, downward to the wrist and fingers; some also take the shoulder joint as the axis forward to the chest, backward to the scapula area, and some radiate to the triceps, deltoid or biceps area, at which time it should be carefully examined to distinguish it from cervical spondylosis and heart disease.