Kinematics and Shoulder Belt Engagement of Children on Belt-Positioning Boosters during Emergency Braking Events

Emergency braking can influence children’s posture and seatbelt interaction. To better protect children in crashes preceded by emergency braking, this study a ims to quantify kinematics and seatbelt engagement during braking events . Eighteen rear‐seated children were exposed to braking events with 1 g deceleration in a passenger vehi cle, restrained by the seatbelt on a booster cushion and an integrated booster cushion. Vehicle acceleration and video data were analysed to m easure head displacement and shoulder belt position. On the booster cushion the belt was generally mid‐sho ulder and lower on the torso with a gap, while on the integrated booster cushion i t was closer to the neck and hi gher on the torso without a gap. Average forward head displacement was 160 mm on the booster cushion and 150 mm on the integrated booster cushion. Generally, the belt maintained the same position on the shoulde r throughout braking, with exceptions influenced by shifted initial positions or non‐standard motions. Braking e vents placed the head approximately 150‐190 mm forward from the initial position, influenced by booster, statu re, and initial seatbelt positioning. This reinforces the importance of maintaining mid‐shoulder or close to neck bel t positions and upright, centred postures prior to emergency braking, which may influence the likelihood of imp acting the vehicle interior and sustaining head injuries in a subsequent crash