Muscular and Kinematic Responses to Rear-End and Oblique Collisions in a Bumper Car-Based Whiplash Model

Abstract

This study investigates cervical muscle and head–neck kinematic responses during low-speed collisions using bumper cars as a test platform. Thirty-four healthy adult volunteers experienced four collision conditions: rear-end (neutral head), rear-end with head turned ~45°, oblique impacts, and unstructured free-driving to simulate real-world unpredictability. Surface EMG, 3D motion capture, and inertial sensors measured muscle activity and kinematics. Preliminary results show females exhibited significantly higher normalized cervical muscle activation than males across all conditions, especially in the posterior paraspinal muscles during rear-end and oblique impacts. These findings suggest sex-specific differences in muscular responses to whiplash-relevant loading, with potential implications for understanding injury risk. The study provides novel data on the influence of head posture, impact direction, anticipation, and sex on low-speed impact biomechanics.