Fig. 4

Lateral radiographs of the cervical spine in the forward flexed neck group. The angle between the two lines at the posterior borders of the C2 and C7 vertebral bodies was measured as the curvature of the cervical spine. A pre-experiment lateral radiograph of the rat cervical spine shows normal lordotic shape of the cervical spine (a), the decrease of cervical curvature after the flexed brace wear (b), a lateral cervical spine radiograph at 4 weeks and after the flexed brace wear shows mild cervical kyphosis (c), and a radiograph taken 6 weeks after the flexed brace wear reveals an obvious cervical kyphotic deformity (d)