To gain a better understanding of the movement of head and cervical spine experiments were performed based on PMTO’s (Post Mortal Test Objects) and Volunteers. All experiments were performed on a crash sled. The change of velocity during the impact was varied between 6 km/h and 15 km/h. The acceleration behaviour of the sled was based on measurements from real collisions from cars equipped with Kienzle UDS™ (Unfalldatenspeicher = Accident Data Recorder). The mean accelerations varied between 2 and 8 g. All experiments were documented with High Speed Video (1000 pps). The accelerations of the sled were measured with two Kienzle UDS. For some experiments, the accelerations of head and chest were measured by three axis accelerometers. To visualise the movement of the cervical spine, during the impact, two vertebra bodies of the PMTO’s were marked with targets. Their movement was observed during the impact phase for various boundary conditions.

These studies have shown that improvements in the construction of seat and head restraint could reduce the risk of neck injuries during rearend impact.