Periarthritis, also known as frozen shoulder, frozen shoulder, frozen shoulder, or frozen shoulder, is a common condition characterized by pain and inconvenience in the shoulder joint. It is more common in manual laborers, more on the left side than on the right side, and can develop on both sides successively. In a few patients, the disease may develop bilaterally. People who have a history of injury to the shoulder or a history of local external fixation, cold, or hemiplegia are prone to develop the disease, but there are also people who develop the disease without any cause. The most obvious symptom is pain, which gradually appears in one part of the shoulder and is clearly related to movement and posture. As the disease progresses, the pain expands and involves the middle part of the upper arm, accompanied by limitation of shoulder joint movement. The degree and nature of the pain varies widely, from dull pain to cutting pain, or severe sharp pain if you want to increase the range of motion. In severe cases, the affected limb cannot comb the hair, wash the face or buckle the belt. At night, the affected limb cannot brush its hair, wash its face, or buckle its belt, and it wakes up with pain due to turning and moving the shoulder. The pain and muscle spasm can be limited to the shoulder joint, but can also be radiated upward to the back of the head, downward to the wrist and fingers, or backward to the scapula and forward to the chest; some radiation can also reach the forearm. The local pressure points in frozen shoulder are extensive. The location of the pressure points and the degree of pressure pain are not consistent depending on the stage of the disease. Patients can still point out the pain points at the beginning, but later the range expands and the pain is felt to come from the humerus. The limitation of abduction, external rotation and posterior extension of the shoulder joint is most obvious, and in a few cases, the limitation of adduction and internal rotation is also limited, but the limitation of forward flexion is less. In older patients or those with longer duration of disease, osteoporosis of the shoulder, or calcification of the supraspinatus tendon and subacromial bursa may be seen on x-ray radiographs. If left untreated, the entire course of frozen shoulder can go through three phases, namely the beginning phase, the freezing phase, and the thawing phase. Beginning phase: The beginning phase is characterized by the patient’s painful symptoms in the shoulder joint, which may be limited to the anterolateral aspect of the shoulder joint or may extend to the deltoid muscle. The shoulder joint gradually develops stiffness. Freezing phase: The pain can be mild or severe, and it is characterized by the patient’s sleep being affected by the increase in pain at night. When the shoulder joint moves, it can cause strong pain and muscle spasm, so that the movement of the shoulder joint can be completely restricted, as if it is frozen. Thawing stage: The pain is mild, the shoulder joint starts to relax gradually, and the range of motion of the upper arm increases gradually. The treatment of frozen shoulder is mainly conservative and should be tailored to the symptoms of different periods. In the beginning stage of frozen shoulder, i.e. the painful stage, the patient’s pain symptoms are heavy and the pain causes muscle spasm, resulting in dysfunction. Therefore, the treatment is mainly aimed at relieving pain and preventing joint dysfunction, and the corresponding treatment methods are as follows: sling braking method, so that the shoulder joint can be fully rested; physical therapy methods, including electrotherapy, warm compresses, cold compresses, etc.; medication, such as internal anti-inflammatory and analgesic drugs and external antispasmodic and analgesic tinctures, if necessary; nerve block method, the most commonly used is the suprascapular nerve block, which can also be injected into the most obvious local pressure pain. The most common method is suprascapular nerve block. Note that massage should only be used after the acute period to improve blood circulation and promote local inflammation. If massage is used too early in the acute stage, it will aggravate the pain and prolong the course of the disease. Freezing phase During the freezing phase of frozen shoulder, joint dysfunction is the main problem. The treatment methods used are physiotherapy, massage, medical sports, etc. The purpose is to release adhesions, expand the range of motion of the shoulder joint and restore normal joint function. For patients with severe frozen shoulder, adhesion release can be performed under brachial plexus anesthesia if necessary. At this stage, it is very important to insist on the functional exercise of the shoulder joint. In addition to passive exercises, the patient should actively cooperate and carry out functional training of active exercises, which is an extremely important part of the whole treatment process. Thawing period The thawing period, i.e. the recovery period, is mainly to eliminate residual symptoms, mainly to continue to strengthen functional exercise, enhance muscle strength, restore the scapular muscles that have undergone disuse atrophy in the first stage, and restore the normal elasticity and contraction function of deltoid muscles and other muscles, in order to achieve comprehensive recovery and prevent recurrence.