Persistent and severe shoulder pain, often due to dislocation of the shoulder joint. There is a clear history of trauma. Traumatic anterior shoulder dislocation is associated with a clear history of trauma, shoulder pain, swelling and dysfunction. The injured limb is flexibly fixed in a mildly abducted internal rotation position with the elbow flexed and the affected forearm supported by the healthy hand. What are the easily confused symptoms? Shoulder dislocation is divided into anterior and posterior dislocation according to the position of the humeral head. 1. Anterior dislocation of the shoulder joint is very common and is often caused by indirect violence, such as when the upper limb is abducted and externally rotated during a fall, the palm of the hand or the elbow lands on the ground, and the external force impacts upward along the longitudinal axis of the humerus, and the humeral head tears off the joint capsule from the weak part between the subscapularis and the large garden muscle and comes out forward and downward, forming an anterior dislocation. The humeral head is pushed under the rostral process of the scapula, forming a sub rostral dislocation. If the violence is greater, the humeral head moves forward to the subclavian, forming a subclavian dislocation. 2.Posterior dislocation of the shoulder joint It is rare, and is caused by the action of forward to backward violence on the shoulder joint or by landing on the hand when the shoulder joint falls in the internal rotation position. Posterior dislocation can be divided into subscapularis and subacromial dislocation. If the shoulder joint dislocation is not treated properly at the early stage, habitual dislocation may occur. Traumatic anterior shoulder dislocation has an obvious history of trauma, pain, swelling and dysfunction of the shoulder, and the injured limb is fixed in a mildly abducted internal rotation position with the elbow flexed and the affected forearm supported by the healthy hand. The appearance is a “square shoulder” deformity, with the shoulder crest protruding significantly and the subacromial hollow. The head of the humerus can be felt in the axilla, under the rostral process or under the clavicle. The injured limb is mildly abducted and cannot be held against the chest wall, such as when the elbow is placed against the chest, the palm of the hand cannot touch the opposite shoulder at the same time (Dugas sign, i.e. positive shoulder hitch test). X-ray examination can clarify the type of dislocation and determine the presence or absence of fracture.