Real world crash investigation constitutes the source of all safety research. It gives information on priorities in terms of body segments to protect, crash configurations and impact severities. It can also provide injury tolerances and allows the verification of the efficiency of protective devices. However, some limitations exist, in particular the precision of information about crash conditions. Even with the best diagnosis, occupant position before the crash is generally still uncertain. This lack of precision can be somewhat compensated by the number of real world crash cases which far exceed the number of biomechanical cases. Nevertheless, biomechanical investigations allow compensation of the shortcomings of crash investigations. Probably the most important biomechanical contribution is the definition of human behaviour, without which crash investigations remain only observation. Human substitutes are needed to provide engineers with tools for improving safety. Only biomechanical research is able to give specifications for the development of such substitutes. Both behaviour and injury criteria are important to define. Information on human behaviour is needed in order to mimic injury mechanisms, criteria are needed to measure them. If one or the other is missing, injury protection can not be evaluated. Both disciplines can contribute to the definition of injury risk curves. The use of the two disciplines together provides tools for developing safety systems and allows the evaluation of their efficiency.
Abstract