A New Neck Injury Criterion Candidate for Rear-end Collisions Taking into Account Shear Forces and Bending Moments

It is generally accepted today that the cervical spine of a car occupant who is involved in a low-speed rear end impact may suffer from soft tissue neck injuries leading to long-term impairment. Therefore, to assess the risk of sustaining such injuries is a major issue in traffic safety, and various neck injury criteria are being discussed for this purpose. In this study a new candidate for such an injury predictor, called Nkm, was developed. Results from a total of 37 sled tests with various car front seat models were evaluated to validate the new criterion. These results indicate that the new criterion offers the possibility to assess the kinematic phase of forward motion of a rear-end collision. In contrast, the NICmax which was also calculated for these tests allows to evaluate the retraction phase only. Furthermore, the influence of the seat design on its protective potential could be related to the Nkm values obtained.