Responses of the scaled pediatric human body model in the rear- and forward-facing child seats in simulated frontal motor vehicle crashes.

The study presents the first-ever endeavor at developing 18-, 24-, 30-, 36-, 42-, and 48-month-old pediatric finite element models from the 6-year-old PIPER human body model as a baseline and comparing their responses systematically in rear-facing and forward-facing simulations across similar boundary conditions. A 6-year-old PIPER model was scaled down to create anthropometric models of the 18-, 24-, 30-, 36-, 42-, and 48-month-old child using the PIPER scaling tool. The models were installed on a convertible car seat (rear-facing and forward-facing configurations) installed with a 3-point lap-shoulder belt in the rear outboard seat of a 2012 Toyota Camry vehicle model finite element model and setup for full-frontal crash simulation (24 , 120 ms pulse). The forward-facing models showed higher head resultant accelerations for 24-, 36-, 42-, and 48-month-old models (reduction for rear-facing seats ranging from 10% to 32%). For the 18- and 30-month-old models, the maximum head acceleration showed similar values (difference of less than 10%). Upper neck forces and moments were consistently lower for rear-facing models compared to forward-facing. The neck forces were reduced by 83%-90% and the neck moments were reduced by 63%-85% in the rear-facing models compared to their respective forward-facing configurations. The reduction in head injury criterion (HIC) for rear-facing models ranged from 14% to 51%. The neck injury criterion () for all forward-facing models was 6 to 9 times the values of their rear-facing counterpart. The study shows the potential benefit of rear-facing orientation compared to forward-facing for children up to 4 years of age in a controlled environment.