Determining Out-of-Position Occupant Kinematics Using 3D Scan Data and MADYMO
Background
A woman was involved in a low-speed, rear-end collision while waiting to turn right onto a roadway. The complaint alleged that the woman sustained injury to her cervical spine as a result of the incident, including a bulging annulus and a herniated disc. Her testimony stated that she was looking left for oncoming traffic at the time of impact, which made her an "out-of-position occupant" deviating from a typical face-forward normal seating position.
Process
Explico was retained to investigate the claim that the incident caused or substantially contributed to the woman's cervical spine herniation. To specifically address the testimony that the woman was looking left at the time of impact, Explico’s team of experts performed a 3D scan of the woman seated to capture her body in two positions or situations: (1) “looking left” while in the vehicle, and (2) sitting “normal” in a face-forward position while in the vehicle. The 3D scan measurements were then input into a subject-specific MADYMO simulation to evaluate the response of the cervical spine in both the "looking left" and "normal" positions. To demonstrate the occupant kinematics in both scenarios, Explico built a custom application that integrated the 3D scan data and MADYMO results into an easy-to-use visualization.
Results
The MADYMO "normal" seating position cervical compression results were consistent with the "looking left" results, indicating that her looking left had no effect on the amount of compression experienced by her cervical spine during the subject incident. The cervical compression in both scenarios was substantially lower than injury assessment reference values and the compression experienced during activities of daily living. Explico determined that there was no reasonable basis to conclude that the incident could have caused or substantially contributed to her cervical herniation, despite her being an out-of-position occupant.
