Age Differences in Occupant Motion during Simulated In-Vehicle Swerving Maneuvers

Background: With active safety and automated vehicle features becoming more available, unanticipated pre-crash vehicle maneuvers, such as evasive swerving, may become more common, and they may influence the resulting effectiveness of occupant restraints, and consequently may affect injury risks associated with crashes. Therefore, the objective of this study was to quantify the influence of age on key occupant kinematic, kinetic, and muscular responses during evasive swerving in on-road testing. Methods: Seat belt-restrained children (10-12 years old), teens (13-17 years old), and adults (21-33 years old) experienced two evasive swerving maneuvers in a recent model sedan on a test track. Kinematics, muscle activity, and seat belt load distribution were determined and analyzed. Results: Compared to teens and adults, children showed greater head and trunk motion (p < 0.03), but similar muscle activation in the into-the-belt direction of swerving. In the out-of-the-belt direction, children showed head and trunk motion more similar to teens and adults (p < 0.02), but with greater muscle activation. Conclusions: Children showed different neuromuscular control of head and trunk motion compared to older occupants. This study highlights differences in the relationship between kinematics and muscle activation across age groups, and provides new validation data for active human body models across the age range.