Cervical injury mechanism based on the analysis of human cervical vertebral motion and head-neck-torso kinematics during low speed rear impacts

Twelve volunteers participated in the experiment under the supervision of Tsukuba University Ethics Committee. The subjects sat on a seat mounted on a sled that simulated actual car impact acceleration under different impact speeds, seat stiffness, neck muscle tension, and alignment of the cervical spine for the parameter study of the head-neck-torso kinematics and cervical spine responses. The muscle activity was measured with surface electromyography. The cervical vertebrae motion was recorded by cineradiography and analyzed to quantify the rotation and translation of cervical vertebrae at impact. The motion patterns of cervical vertebrae in the crash motion and in the normal motion were compared.