Polar Light Technologies (Sweden)

The protection of children in motor vehicle crashes has improved since the introduction of child restraint systems. However, motor vehicle crashes remain one of the top leading causes of death for children. Safe design of vehicles should provide protection for the whole population in case of an accident. However, children are not small adults. As the body grows and matures, the biomechanical response changes. The development of head, neck, thorax, and pelvis changes the biomechanics of child bodies. Children under 4 years of age have a proportionally large head and an anthropometry of the neck that have led to crash fatalities for forward-facing children. The rear facing child seat distributes the crash load over a large area of the body and supports the mass of the head, which has proved to be a very efficient protection for these young children. The pelvis is not fully developed until after 12 years of age and before that there is an increased risk of poor seat belt interaction and submarining, where the lap belt slips over the pelvis resulting in severe injuries to the soft tissues in the abdominal area. Also, on-road driving studies showed that children frequently slouched when seated directly on the rear seat of the car. Slouching increases the risk of submarining. To ensure good protection, children between 4 and 12 years of age should use belt-positioning boosters together with the vehicle’s seat belt. Recent years have seen a rapid development and implementation of vehicle systems for autonomous driving and emergency maneuvers. Volunteer studies indicate that pre-crash loading forces affect the kinematics of forward-facing children, e.g., resulting in large head displacements that may increase the risk of head impacts. By providing child adaptability of the vehicle, the protection of child passengers can be further optimized. An example of this is the significant reduction of lap belt misuse when using integrated boosters. Today, computer-aided engineering is an essential part of vehicle development, and it is anticipated that safety assessments will increasingly rely on simulations. Simulation models representing children of different ages and sizes have become and will be increasingly important for the development and assessment of safety systems that accounts for population diversity. The review of human whole-body models covers both multi-body and finite element models developed for crash simulations. The European project PIPER developed an open-source scalable child model and pre-processing tools. Many children that were killed or seriously injured in traffic were not inside the vehicle, rather they were pedestrians, cyclists, or motorcycle passengers. Hence, it is important to account for the behavior and biomechanics of children in all aspects of traffic safety, from urban planning to design of energy-absorbing vehicle fronts or pedestrian friendly bonnets to cycling helmets. Child safety should not be an expensive add-on option, rather it should be standard in all vehicles. For low- and middle-income countries and families, affordable child restraint systems can be developed based on the basic principles of child biomechanics.