The lognormal curves do not have formulae. Figure II-1 shows the chance of fatality predicted by the two curves. As part of the neck discussion, there are protection reference values for children and adults provided. Slight differences are recommended for 5th and 95th percentile dummies. This reflects the skull of infants not having hardened.
Different values relate to different injury levels for children and for adults.
A table of neck injury curves was developed for AIS 2 injuries and for AIS 5 injuries. AIS 5 injuries are considered to be equivalent to fatalities for this analysis. The chance of injury and fatality given an overall neck injury risk value is shown in Table II-5. The agency is working to resolve these differences. The agency has also developed protection reference values for arm injuries.