Analysis of Vertebrae Motion with Computer Simulation Using Elementary Contact Pairs

To simulate the motion of two adjacent vertebrae a computer model is created. Described in the paper is the mathematical modelling of a vertebrae pair using multibody methods and impact analysis techniques with elementary contact geometry for the facet joints. The ligaments and the intervertebral disc are modeled as a parallel connection of a spring and a damper. The results are compared with existing approaches and experimental data. In order to enhance the results, piecewise linear functions instead of a constant spring stiffness for the model of the intervertebral disc are used. The simulation allows the motion in three-dimensional space (three translations and three rotations, see figure 1). The investigations are focused on the vertebrae pair C5-C6 but can be easily extended to other vertebrae. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)