From the external occipital protuberance to the waist, there is a supraspinous ligament connected behind the spinous processes. The fibers are long. Generally, it manifests as a thicker nuchal ligament, which plays an important role in the stability of the occipital-cervical region; in the thoracic segment, the supraspinous ligament is relatively weak; while the supraspinous ligament in the lumbar region is also strong, but in the lumbar5~Sacrum1is often absent or relatively weak, which is prone to cause injury to the deep inter-spinous ligament.