Examining the relationship between whiplash kinematics and a direct neurologic injury mechanism

Despite the prevalence of whiplash-related injuries, a connection between clinical symptoms and injury mechanism has been elusive. Previous studies have attempted to correlate the whiplash kinematic response to injury mechanisms; however, none has specifically examined the potential for neurologic involvement due to foraminal occlusion. This biomechanical study measured cadaver cervical spine whiplash kinematics and compared these with changes in the neural space geometry of the cervical spine, providing a measure of the direct neurologic injury potential. Extension and shear displacements of each cervical level were measured and found to be similar to that reported in the literature and within the tissue's physiologic limits. Further, changes to the spinal canal and intervertebral foraminal geometry were recorded during whiplash and cross-sectional area changes were documented (up to 15.3%). Because these foraminal occlusions were smaller in magnitude than those resulting from normal cervical motion, our findings do not support direct neurologic injury resulting from segmental vertebral kinematics as a whiplash injury mechanism.