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Two mathematical head-neck models have been developed using MADYMO: a global model and a detailed one. The global model comprises rigid head and vertebrae connected through nonlinear viscoelastic intervertebral joints representing the lumped behaviour of disc, ligaments, facet joints and muscles. The model response to frontal impacts agreed reasonably with volunteer responses. The detailed model comprises rigid head and vertebrae connected through linear viscoelastic discs, nonlinear viscoelastic ligaments, frictionless facet joints and contractile muscles. The model response to lateral impacts agreed excellently with volunteer responses, whereas the response to frontal impacts showed that the model was too flexible. The global model is especially suited for use in complex simulations as occupant behaviour in car crashes, whereas the detailed model is particularly suited for neck injury assessment.

At the Naval BioDynamics Laboratory (NBDL) in New Orleans a large series of human volunteer experiments has been conducted by Ewing and Thomas [1]* to determine the dynamic head-neck response. From a number of these experiments Wismans et al. [2] determined omni-directional dummy head-neck performance requirements relative to a non-rotated T1 coordinate system (i.e. the head motions incorporate the influence of the thoracic column flexibility). In 1987, the frontal volunteer head-neck response was compared with the response of postmortem human subject (PMHS) experiments [3]. One of the findings was that the volunteer T1 rotations differ significantly from the PMHS T1 rotations which was explained by measurement “errors” in the T1 instrumentation. The present paper is an extension of the previous work [2,3]. A detailed analysis of the high-speed films revealed that the volunteer T1 instrumentation mount was not firmly mounted to the spine.

The three-dimensional head-neck model of Deng and Goldsmith (J. Biomech., 1987) was adapted and implemented in the integrated multibody/finite element code MADYMO. The model comprises rigid head and vertebrae, connected by linear viscoelastic intervertebral joints and nonlinear elastic muscle elements. It was elaborately validated by comparing model responses with the responses of human volunteers subjected to frontal and lateral sled acceleration impacts. Fair agreement was found for both impacts. Further, a sensitivity analysis was performed to assess the effect of parameter variations on model response. The model proved satisfactory and may be used as a tool to improve restraint systems or dummy necks.