Citation

Boström O, Bohman K, Håland Y, Kullgren A, Krafft M. Proc. IRCOBI 2000; 28: 249-264.

Copyright

(Copyright © 2000, International Research Council on Biomechanics of Injury)

DOI

unavailable

PMID

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Abstract

The Abbreviated Injury Scale (AIS) 1 neck injury is the most frequent disabling injury in frontal impacts. Recent research has shown that, similar to rear impacts, the crash pulse level rather than the speed change influences the risk of sustaining a short- or long-term injury. Also similar to rear impacts, different injury mechanisms have been proposed. In this study, new AIS1 neck injury criteria (NIC) for frontal impacts were proposed and evaluated, namely NIC-protraction and the established AIS3+ criteria Nij and upper neck flexion moment My (sub flexion). The NIC-protraction calculation is analogous to NICmax shown to be applicable and relevant for evaluating the neck load in rear-end impacts. Totally 172 belted occupants involved in 144 rear frontal crashes with recorded crash pulses were simulated and analyzed using MADYMO models of the HIII 50th percentile male. The injury outcome in terms of short-term, long-term or no neck injury, as well as the crash pulse and the utilization of airbag and belt-pretensioner were known. At least 70% of the NIC-protraction, Nij and My (sub flexion) values associated with the non-injured occupants were lower than the values for at least 70% of the long-term injured. In the development of frontal impact protection systems NIC-protraction, Nij and My (sub flexion) should therefore at least be lower than AIS1 long-term neck Injury Assessment Values (IARV). The rounded median values for the long-term injured were in this found to be 25 m2/s2 for NIC-protraction, 0.2 for Nij and 40 Nm for My (sub flexion).