Effect of intercostal muscle and costovertebral joint material properties on human ribcage stiffness and kinematics

Abstract

Current finite element (FE) models of the human thorax are limited by the lack of local-level validation, especially in the ribcage. This study exercised an existing FE ribcage model for a 50th percentile male under quasi-static point loading and dynamic sternal loading. Both force-displacement and kinematic responses of the ribcage were compared against experimental data. The sensitivity of the model response to changes in the material properties of the costovertebral (CV) joints and intercostal muscles was assessed. The simulations found that adjustments to the CV joints tended to change the amount of rib rotation in the sagittal plane, while changes to the elastic modulus and thickness of the intercostal muscles tended to alter both the stiffness and the direction and magnitude of rib motions. This study can lend insight into the role that the material properties of these two thoracic structures play in the dynamics of the ribcage during a frontal loading condition.

Keywords::

• finite element modelling
• ribcage
• intercostal muscles
• costovertebral joints
• thoracic modelling

Acknowledgements

The funding for this study was provided by the Global Human Body Models Consortium and Takata Holdings. The authors thank Philipe Vezin at IFSTTAR for providing the experimental data for the dynamic tests. The authors would also like to thank Deborah Varoqui of the Rehabilitation Institute of Chicago for her assistance with formatting the figures.