Effects of individual spine curvatures - A comparative study with the help of computer modelling

Abstract

The double-S curvature of the human spine underlies a wide range of variations. This individual characteristic depends on the constitution and is built in the course of life by daily stress. Is the spine subjected to high stress, degenerative damages may be the consequences. For a better knowledge about these damages the relationship between spine curvature and distribution of the load is of interest. In order to determine the stress of the internal structures an appropriate method is computer modeling. We present two Multi Body System- (MBS-) models of the lumbar spine with different spinal curvatures. To simulate the upright standing with both models an external force of 500N, which corresponds to the weight of the upper body, is applied to the top surface of vertebra L1. For both models, the forces in the intervertebral discs, facet joints and ligaments are calculated and the effects of the different spinal curvature are shown comparatively. In both models the mechanical properties of intervertebral discs, facet joints and ligaments are implemented. The models are validated by comparing the calculated kinematic values with finite element modeling data and in vivo studies from literature. © 2012 by Walter de Gruyter Berlin Boston.