Although airbag technology has been beneficial to the vast majority of occupants involved in vehicular collisions, there are certain scenarios that have been identified as potentially harmful to the occupant who is improperly positioned near a deploying airbag. A deploying airbag that expands around the neck region may thrust the occupant's head up and back causing a tension-extension mechanism of injury in the neck structures. The purpose of this study was to evaluate this injury in several different models, and to develop methods for improved injury criteria in at-risk populations. A series of tests were conducted on fresh human cadaver head and neck complexes by potting the preparation at T1-T2 and applying load to the head. Another series of experiments was done with completely intact preparations. Tests were conducted at both quasistatic and dynamic loading rates up to 8 m/sec. Specimens tested at quasistatic loading rates generally produced failure in the lower levels of the cervical column. In contrast, specimens tested dynamically and in an intact state demonstrated consistent higher level cervical trauma. The study results demonstrate that upper cervical spine trauma occurring in the real world involves a highly dynamic loading vector and unique boundary conditions. Human tolerance criteria for this region in the at-risk populations of children and small females can be evaluated with further development of these models. (A)
Abstract