There are several possibilities for neck shortening: 1, it is not really short, it may be because of getting fat, chin, shoulder back fat accumulation increases, appearing neck shortening. 2, traumatic fracture of cervical spine, compression fracture, comminuted fracture of vertebral body does not get ideal reset, resulting in shortening of vertebral length, thus causing neck shortening. 3, cervical intervertebral disc degeneration, normal intervertebral disc has rich water inside, with The cervical spine is shortened and the neck is shortened to a certain extent. 4, degenerative changes of bone and joint, mostly seen in the elderly, with age, bone loss, osteoporosis, reduced bone density, with the effect of gravity, the bones are slowly compressed and flattened, including the cervical spine.