Comparing the kinematics of the head and spine between volunteers and PMHS: A Methodology to estimate the kinematics of pediatric occupants in a frontal impact

Traumatic brain and skull injuries are the most common serious injuries sustained by children in motor vehicle crashes. The spine dictates the position and orientation of the head during the impact. Research has shown major discrepancies between the spinal kinematics of current pediatric Anthropomorphic Test Devices and humans during frontal impacts. The paucity of pediatric experimental data requires of applying scaling methods to predict the pediatric response using adult data. This paper presents data on four different experimental data sets corresponding to non-injurious low-speed impacts with pediatric and adult volunteers and to low-speed and high-speed impacts with Post Mortem Human Surrogates (PMHS). Two published scaling methods (mass scaling and SAE scaling) were assessed using volunteer data and failed to predict the actual pediatric displacement. A new scaling method was developed to improve the prediction of the pediatric response at low speed. The new method was then applied to the high-speed PMHS data to provide an approximation of the displacements of the head, thoracic spine and pelvis of a 6-year-old occupant in a 40 km/h frontal impact. The limitations of the method are discussed in the paper.