I remember the other day an old man in his 60s came to me accompanied by his children and said that he had pain and limited movement in and around his right shoulder joint. After I gave the old man a physical examination, I suggested that he get an MRI to rule out a rotator cuff injury? It turned out to be a rotator cuff tear. The “frozen shoulder” that had been tormenting the old man for more than half a year had been misdiagnosed and mistreated, and the method was not right for him, so the results were not good. With the development of medicine and the popularity of imaging technology such as MRI, the diagnostic thinking that shoulder pain is frozen shoulder can be said to be outdated. The first is rotator cuff tears. The rotator cuff, also known as the rotator cuff of the scapula, is a collective name for the four tendons around the humeral head of the shoulder joint, including the supraspinatus, infraspinatus, teres minor and subscapularis tendons, which play a leading role in the forward flexion, abduction, supination, internal rotation, external rotation, posterior extension and forward flexion of the shoulder joint in different directions. Rotator cuff tears, i.e. partial or complete rupture of the supraspinatus, infraspinatus, teres minor and subscapularis tendons, are a common cause of shoulder pain and dysfunction. Because the shoulder joint is the most mobile joint in the body, and the rotator cuff is in a special position, the movement is gliding between two bones, so when the shoulder joint does abduction and supination, the rotator cuff is prone to friction with the bones above causing micro-injuries. However, the rotator cuff is an area that lacks blood flow, so excessive wear and tear is not conducive to repairing minor injuries, which can lead to rotator cuff degeneration. Therefore, it is possible to tear the rotator cuff with minor external forces during daily activities, and even more so with severe violence, and the tear will not heal easily due to poor blood flow, gravity and muscle pulling. The symptoms of a rotator cuff tear are very similar to those of frozen shoulder. Patients also experience shoulder pain and limited movement, and the pain is more severe at night than during the day, which is often mistaken for frozen shoulder. The symptoms of a rotator cuff tear are very similar to those of frozen shoulder. Patients also experience shoulder pain and limited movement, and the pain is worse at night than during the day, which is often mistaken for frozen shoulder. Different rotator cuff tendon tears cause different symptoms of weakness. For example, supraspinatus tendon tears (the most common type) present as weakness during anterior and supraspinatus movements of the arm. Many patients do not realize how much strength they have lost when they have a rotator cuff tear. If the rotator cuff is torn, the patient will not be able to lift the upper arm or maintain the previous degree of rotational mobility. The pain will be more pronounced at night and will radiate into the upper arm. The lateral shoulder has a rostral shoulder dome made up of the acromion, rostral shoulder ligament, and rostral process. A triangular gap is formed between the rostral shoulder dome and the humeral head called the subacromial space, also known as the second shoulder joint. Subacromial impingement syndrome is a clinical condition that occurs when the subacromial joint impinges on the subacromial tissues during shoulder supination and abduction movements due to anatomic or dynamic reasons. The causes of subacromial impingement syndrome can be summarized as follows: First, anatomical abnormalities cause a narrowing of the supraspinatus muscle outlet due to a decrease in the acromion-humeral head spacing, causing the rotator cuff to be squeezed between the humeral head and the rostral arch of the shoulder. The low acromion and the hook deformity below the anterior acromion are considered to be the most common intrinsic causes of extrusion. In particular, supraspinatus outlet stenosis is the main etiology of subacromial impingement syndrome. Thickened rostral shoulder ligaments, acromioclavicular joint and subacromial tuberosity, and humeral tuberosity may also contribute to bursal and supraspinatus tendon injury. It occurs when the affected limb is repeatedly and excessively used, especially when the affected limb exceeds the head movement and the worker is subjected to the collision of the rostral arch and the acromion during shoulder abduction and forward flexion, and the repeated and minor impact and stretching injuries lead to the damage of the static and dynamic stability structures, shoulder joint instability, mild upward displacement of the humeral head, secondary impingement, inflammation and degeneration of the rotator cuff, and even tearing. A vicious cycle is created between this instability, impingement and rotator cuff injury; third, other impingement signs that result in rotator cuff injury, such as primary degenerative rotator cuff lesions and posterior supra-articular glenoid impingement signs. Shoulder instability, also known as shoulder subluxation, refers to a series of disorders including shoulder dislocation, subluxation, pain and laxity after instability. The clinical symptoms are mainly dull pain in the shoulder, which is aggravated during passive forced external rotation, abduction movement or weight bearing. Most patients feel a sense of glenohumeral instability and have joint interlocking and popping performance. A passive push-pull test of the humeral head in the anterior-posterior direction reveals excessive laxity of the acromioclavicular joint. More than half of the patients have fatigue and weakness, especially the inability to lift heavy objects for a longer period of time. About 1/3 of patients have numbness around the shoulder. In addition, there is muscle atrophy and limited joint movement, causing inconvenience in daily life and work. Thoracic outlet syndrome is a general term for a series of vascular and neurological symptoms of the upper extremity caused by compression of the brachial plexus nerve and subclavian artery at the outlet of the upper thorax for some reason. The main clinical manifestations are (dull) pain and numbness in the shoulder, arm and hand, or even muscle atrophy and weakness, bruising and coldness in the hand, and weakened radial artery pulsation. Although the pain in the affected shoulder and upper extremity, and the pain increases during shoulder abduction and internal rotation, is somewhat like frozen shoulder, the severity of the disease is more severe than frozen shoulder, and in severe cases, abnormal sensation in the ulnar side of the forearm and hand, and even muscle paralysis may occur. Shoulder-hand syndrome, alias reflex sympathetic dystrophy and painful dystrophy, is a common complication of stroke sequelae and is one of the major obstacles to recovery from stroke, heart attack, cervical spondylosis, upper extremity trauma, paraplegia and related pulmonary diseases. The main clinical manifestations are pain, sensory abnormalities, vascular dysfunction, edema, abnormal sweating and nutritional disorders in the affected shoulder joint, which can lead to finger deformation and complete loss of hand function in severe cases. Inappropriate passive activities, incorrect movement patterns, as well as shoulder and wrist injuries, obstruction of upper limb fluid return, and vasomotor dysfunction after central nerve injury can all lead to shoulder joint trauma and trigger shoulder-hand syndrome. Tuberculosis of the shoulder joint has a slow progression, with symptoms appearing gradually. The first symptom is pain (swelling) in the shoulder (below the deltoid muscle), which is often severe when the affected limb is abducted or externally rotated. In the early stage, there is no characteristic clinical manifestation or x-ray manifestation of shoulder joint tuberculosis and frozen shoulder, so it is easy to confuse them. Tumors around the shoulder may also cause shoulder pain or dysfunction of the shoulder arm when they reach a certain stage of growth. The difference with frozen shoulder is that the shoulder pain in the affected area is gradually aggravated and the painful area is gradually enlarged due to the growth of tumor. Benign tumors have regular shape, soft texture and good mobility, while malignant tumors have irregular shape, hard texture and immovable. Due to the compression of the tumor, functional limitation may occur, and some patients may experience numbness and pain in the shoulder, arm and fingers. Besides, there are other conditions like heart diseases (such as myocardial infarction, angina pectoris, etc.) which sometimes produce pain in the left shoulder, painful sensation in the right shoulder caused by gallbladder diseases (such as gallstones, cholecystitis, etc.), and lung cancer induced peri-shoulder pain and discomfort which are often misdiagnosed as frozen shoulder. Although most of these diseases are presented to us with shoulder pain as the main manifestation, the nature of the disease varies and the location of the lesion is not the same, which requires patients with shoulder pain to go to a qualified doctor at the local public hospital in the first place, so that they can find out the “real culprit” of shoulder pain among many similar manifestations by professional means. “If the shoulder pain is caused by heart disease, gallbladder disease, tumor-induced periarthritis pain and discomfort, then a combination of Chinese and Western medicine should be used to treat the original cause. If you are uncomfortable, combine Chinese and Western medicine to treat the primary disease in order to receive satisfactory results.