Comparison of Q3s ATD Biomechanical Responses to Pediatric Volunteers

Principal Investigator: Yun-Seok Kang, PhD, The Ohio State University

Below is an executive summary of this project. Please note that this summary describes results and interpretation that may not be final. Final interpretation of results will be in the peer-reviewed literature.

Improvements to the design of child restraint systems (CRS) are dependent upon new testing protocols to better understand how children’s bodies respond during crashes and how CRS can best protect them. Under Federal Motor Vehicle Safety Standard (FMVSS) 213, all CRS sold in the U.S. must meet a dynamic testing requirement in frontal collisions. New side impact requirements to FMVSS 213 have been proposed by the National Highway Traffic Safety Administrations (NHTSA) but are dependent upon an adequately biofidelic pediatric side impact anthropomorphic test device (ATD), or crash test dummy. The 3-year-old targeted Q3s ATD is one of the first side impact specific pediatric ATDs that is emerging as a tool to fill this need. This study utilized existing pediatric volunteer data to evaluate the Q3s, which was also subjected to higher severity impacts to compare overall kinematics and kinetics.

These photos show examples of pre- (left) and post-test (right) pictures with a three-point seat belt (top) and CRS (bottom). The post-test pictures were taken after lateral impacts at the high speed condition.

Previously conducted experiments were replicated in order to make a direct comparison between the Q3s and pediatric volunteer data from 4- to 7-year-olds (shoulder tests) and 6- to 8-year-olds (low speed sled tests). Force-deflection data were captured during quasi- static shoulder tests of the Q3s through manual displacement of the shoulder joint. Low-speed far-side sled tests, as well as low, medium, and high-speed sled tests using a Takata bench setup, were conducted with the Q3s at lateral (90°) and oblique (60°) impacts. In testing, the Q3s ATD exhibited greater shoulder stiffness than pediatric volunteers, which may affect loads seen by the Q3s head, torso, and neck during side impact. In low-speed sled testing, the Q3s kinematics displayed rigid body translational motion of the torso followed by independent lateral bending of the head, suggesting cervical and thoracic spine rigidity compared to pediatric volunteers.

While ATDs have been compared to volunteer responses in frontal impacts, this study is the first to extend ATD to pediatric volunteer comparison methods to the Q3s ATD, and among the first to extend these methods to side impacts. These results provide an important step toward ATD pediatric biofidelity evaluation by comparison to volunteer data. Even at low severity impacts, there are important differences in the biomechanical responses of children compared to the Q3s. Identifying, understanding, and making improvements based on these differences will lead to more biofidelic pediatric ATDs and, ultimately, save more children’s lives.

Project Team Member

Thomas Seacrist, MBE, Children’s Hospital of Philadelphia


Meagan Ita, The Ohio State University

IAB Mentors:

Eric Dahle, Evenflo Company Inc.; Jerry Wang, Humanetics Innovative Solutions Inc.; Steve Rouhana, Ford Motor Company; Keith Nagelski, Britax Child Safety, Inc.; Ron Burton, Transportation Research Center Inc.