Occasionally, a rib fracture is caused by a sudden strong contraction of the chest muscles due to a violent cough or sneeze, which is called a spontaneous rib fracture, mostly occurring in the 6th to 9th rib in the axilla. When the ribs themselves are diseased, such as primary tumors or metastases, rib fractures can also occur under very light external forces or without external forces, called pathological rib fractures. Rib fractures occur mostly in the 4th to 7th ribs; the 1st to 3rd ribs are protected by the clavicle, scapula and shoulder girdle muscles and are not easily fractured; the 8th to 10th ribs become progressively shorter and are attached to the cartilaginous rib arch, which has an elastic cushion and reduces the chance of fracture; the 11th and 12th ribs are floating ribs with greater mobility and are rarely fractured. However, when the violence is strong, these ribs can be fractured. A fracture of only one rib is called a single rib fracture, and a fracture of two or more ribs is called a multiple rib fracture. Rib fractures can occur bilaterally in the chest at the same time. Only one fracture per rib is called a single fracture, while two or more fractures are called double or multiple fractures. Sequential multiple rib fractures or multiple rib fractures combined with multiple rib cartilage epiphyseal detachments or bilateral multiple rib cartilage fractures or epiphyseal detachments result in chest wall softening and are called floating chest wall injuries, also known as continuous thorax. Local pain is the most obvious symptom of rib fracture, and it increases with coughing, deep breathing or body movement such as rotation. The pain and the disruption of the thoracic stability can lead to restricted respiratory dynamics, shallow and rapid breathing, and reduced alveolar ventilation. This is especially important in elderly and frail patients or patients with pre-existing pulmonary disorders. In shackle chest, when inhaling, the negative chest pressure increases and the softened part of the chest wall sinks inward; when exhaling, the chest pressure increases and the damaged chest wall floats out, which is opposite to the movement of other chest walls and is called “paradoxical respiratory movement”. Paradoxical respiratory movement can make both sides of the chest pressure imbalance, mediastinum with breathing and move back and forth to the left and right, called “mediastinal oscillation”, affecting blood return, causing circulatory disorders, is one of the important factors leading to and aggravating shock. The thoracic pain and thoracic stability are more serious when the chest is attached to the shackle, and the paradoxical respiratory movement makes the respiratory movement more restricted, the cough is weak, the lung volume and functional residual air volume (FRC) are reduced, the lung compliance and tidal volume are reduced, often accompanied by severe dyspnea and hypoxemia. In the past, it was thought that some gas flowed back and forth between the healthy side and the injured side of the lung with inspiration and expiration, and could not be exchanged with the atmosphere, which was called residual gas convection or oscillatory gas, and was the main cause of respiratory dysfunction. At present, it is believed that swinging air does not exist, but the pulmonary contusion often associated with shackle chest can cause alveolar and interstitial hemorrhage, edema, alveolar rupture and atelectasis, which is an important cause of respiratory dysfunction. Most of the X-rays can show rib fractures, however, rib cartilage fractures, “willow fractures”, fractures without misalignment, or mid-rib fractures are not easily detected on chest films because the ribs on both sides overlap each other. In addition to combined pleural and pulmonary injuries and the resulting hemothorax or pneumothorax, rib fractures are often combined with other thoracic injuries or injuries to sites outside the chest.