[Backward hypertranslation of the head: participation in the whiplash injury mechanism of the cervical spine?].

Based upon a review of the literature, a theory is developed that in whiplash injury the primary mechanism of the trauma is not hyperantiflexion but hypertranslation of the head backwards. Thus a hyperanteflexion (not hyperretroflexion) of the upper cervical spine, probably especially of the atlanto-axial segment, is induced, causing an overstretching of the ligaments concerned (also the alar ligaments) and the joint capsule. The disorder of the propriosensitive information concerning the position of the head relative to the body with chronic disturbances of posture and equilibrium is explained by the thus generated chronic ligamentous instability of the upper cervical spine. In humans our theory is not yet sufficiently supported by experimental results.