MODELING AND SIMULATION OF STATIC DEMANDS OF THE VERTEBRAL COLUMN IN THE SAGITTAL PLANE

Abstract

Studies show an exponential increase of cases of spine deformation in recent years. In the 21st century, there has been recorded an increase in spine deformity in the sagittal plan due to the lack of activity of the individual, his vicious attitude (sitting in the office, at the computer, telephone, etc.), shoes etc. All the physiological changes of the spine are reflected on the diagram of its solicitation. The recorded requests in the spine are greater if one of the three curves gets eliminated or if the spine curves show accentuations. Physiological curves offer flexibility, mobility and appropriate mechanical solicitations to each segment separately. Pathological cases show an accentuation of curvature in the foreground, but also transversal changes at different vertebral levels, and so the 2D static loading approach has to be extended to 3D to model all aspects of deformation. The shape of the spine gets modified once with the position; as a result, the experimental curve through plotting points on the x-rays may lead to a rougher or finer approximation depending on the accuracy of the model. The proposed software application molds the forces acting at intercervical level for the entire spine in neutral position. Properties of spine arc and dashpot are evaluated and modelled on the basis of experimental data. The simulation parameters are based on an existing algorithm, but with original improvements regarding the optimizing and correlation of deformation parameters acting at the level of the vertebrae. The GUI accomplished on the basis of a mathematical considered model will help therapists to assess different situations "in vivo" based on information from x-rays, measurements, etc., but also to observe the distribution of forces acting upon the spine. A better understanding and representation of these pathologies, will help therapists in devising a more accurate treatment plan and thus decrease the number of cases.