EVALUATION OF THE INFLUENCE OF PARAMETERS OF ABDOMINAL PRESSURE ON THE DYNAMIC BEHAVIOR OF THE LUMBAR SPINE IN HUMANS: SIMULATION WITH A LINEAR AND NONLINEAR MODELS

Abstract

The scope of this work is to analyse the variations of behaviour of the human lumbar spine with variations in its stiffness parameters, including abdominal pressure influence neighbour parameters, simulated by a nonlinear mathematical model. Some of the techniques for the clinical diagnosis of dysfunctions acting of the lumber segments of the human spine have been based in the application of posteroanterior forces (PA). The parameters of influence: initial lordotic curvature, positions of the geometric centers of the vertebrae, thorax, and the sacrum-pelvis, and point of application of the posteroanterior force were evaluated from the X-ray image of patients. The nonlinear stiffness characteristic introduced affect the motion stability when periodic posteroanterior forces and impulsive forces are applied to a vertebra. The precise motion of individual lumber segments may allow the use of a particular patient data for obtaining a dysfunction analysis of the segments.

Index Terms - Viscoelastic stiffness, abdominal pressure, stiffness parameters, lumbar dysfunction analysis.