The human spine consists of four parts: the cervical, thoracic, lumbar, and sacral vertebrae. The cervical spine curves forward, the thoracic spine curves backward, the lumbar spine curves forward, and the sacrococcygeal curves backward. The cervical spine is formed by seven vertebrae, the first cervical vertebra is called the atlantoaxial vertebra, the second cervical vertebra is called the cardinal vertebra, and the two vertebrae form the atlantoaxial joint. The cervical three to cervical six vertebrae are typical vertebrae with lateral hooks, forming the hook joint, which is unique to the cervical spine. The thoracic vertebrae consist of twelve vertebrae, the vertebrae are larger in size than the cervical vertebrae, the spinous processes are longer, and the thoracic vertebrae have a thoracic rib joint with the head of the ribs on each side. The lumbar vertebrae consist of five vertebrae, the volume of the lumbar vertebrae is larger than that of the thoracic vertebrae, and the volume of the lumbar three and four vertebrae is the largest.