Abstract: Objective To establish a 3D finite element model of the complete human thoracic cage, and to perform a biomechanical analysis. Methods The multislice computed tomography （MSCT） images of human thorax were obtained and used to develop a 3D reconstruction and a finite element model of the thoracic cage by finite element modeling software. The right hypochondrium area of the model was simulated to sustain the frontal impacts by a blunt impactor with velocities of 4, 6 and 8 m/s, and the distribution of stress and strain after the impact of the model was analyzed. Results A highly anatomically simulated finite element model of human thoracic cage was successfully developed with a fine element mean quality which was above 0.7. The biomechanical analysis showed that the thoracic cage revealed both local bending and overall deformation after the impact. Stress and strain arose from the initial impact area of the ribs, and then spread along the ribs to both sides, at last concentrated in the posterior side of the ribs and near the sternum. Impacts with velocities of 6 m/s and 8 m/s were predicted to cause rib fractures when the strain of the ribs were beyond the threshold values. Conclusion The finite element modeling software is capable of establishing a highly simulated 3D finite element model of human thoracic cage. And the established model could be applicable to analyze stress and strain distribution of the thoracic cage under forces and to provide a new method for the forensic identification of chest injury.

Key words: forensic pathology, biomechanics, finite element analysis, tomography, spiral computed, thorax