The objectives of this research is to develop a biofidelic multi-body model of the whole human spine especially for dynamic analysis of impact situations, such as frontal impact in a car crash, and to generate finite element (FE) models of the specific spinal parts to investigate causes of injury of the spinal components. This novel approach provides a versatile, cost effective and powerful tool to analyse the behaviour of the spine under various loading conditions which in turn helps to develop a better understanding of injury mechanisms.

In this research, the predictions of the multi-body model under dynamic impact loading conditions, such as reaction forces at lumbar motion segments, were utilised not only to have a better understanding of the gross kinetics and kinematics of the human spine, but also to constitute the boundary conditions for the finite element models of the selected spinal components. This novel approach provides more realistic values for impact loadings on the parts of the human spine. The 3-D multi-body model was constructed by using the dynamic simulation software MSC.visualNastran 4D 2001. The model embodied the vertebrae, linear viscoelastic intervertebral discs, muscles retaining passive and active behaviour, and non-linear viscoelastic ligaments. FE analysis software, MSC.Marc/Mentat, was employed to develop and analyse 3-D non-linear finite element models of the selected parts, such as lumbar intervertebral discs. Both models were vigorously validated by using the experimental data published in the literature. Impact simulation analysis results and conclusions, such as stresses in spinal elements, e.g. the intervertebral disc, and the reaction forces at the selected vertebral level were presented.