Child Safety in Car Crashes: A Literature Review
The objective of this literature review is to summarize the knowledge of child safety in cars, for children up to 12 years old, and to identify gaps. The aspects investigated are child anatomy and its development from infancy to adolescence, child injuries and injury mechanisms, injury risk in car crashes, and safety evaluation tools for child restraint systems and vehicle restraint systems.
Numerous studies have been made to calculate the injury risk for children involved in car crashes. Although the calculations were based on several accident databases, the results are similar. In these studies, the injury risk associated with selected factors was analyzed. The factors are usually impact type, impact severity, whether or not the restraint was used, type of restraint, seating position, and age of the child. Efforts were made to study the effect of each one on injury risk by body region and injury severity. It was shown that the head is the most frequently injured body part regardless of crash type or restraint type. The restraint type, impact type, impact severity, and size of the child are the primary factors that determine the level of risk. Further studies are needed to investigate the restraint effectiveness in detail; however, in most databases the sample size limits the possibilities.
Child anatomy and its development are fairly well known, although the growth of children has changed in recent decades due to socio-economic development. This affects the validity of the available anthropometric data. Also, some important data is still missing due to lack of measurement methods.
Many child injuries have been described in case reports by both physicians and vehicle safety researchers. Therefore, injury types are well known, but the injury mechanisms are less well known. Injury mechanisms have been proposed, but validation of such mechanisms is very limited for ethical reasons. Further studies of real life accidents are vital to improve knowledge of injury causes and mechanisms.
The current safety evaluation tools are dummies of several sizes and levels of complexity, and mathematical models of the dummies. Work is currently in progress in several countries to construct mathematical models of children. The work is concentrated on hybrids, where most of the model is a dummy, but with some vital parts modelled from humans. As the work is still in the research and development stage, such hybrids cannot yet be purchased.
The outstanding work in summary is: new measurements of children to gain a better understanding of their anthropometry, further accident investigations to find out more about injury causation and injury mechanisms, and the development of better tools for safety evaluation.