Finite element model of the human neck during omni-directional impacts

Abstract

A 3D Finite Element model was developed under the FE code Radioss, to explore the mechanisms of injury occurring during various kinds of impacts. It represents the head and neck of a 50th percentile human seated in a reference position. It includes a volumic representation of the head, cervical vertebras, intervertebral discs, muscles and soft tissues. Contacts are taken into account between articular facets as well as between spinous processes. The kinematical behaviour of the model was evaluated omni-directionally for various impacts, using published experimental results of head and vertebral 3D motions and accelerations, obtained both on cadavers and volunteers. The model's ability to reproduce injury mechanisms was also assessed; its behaviour was compared to available experimental injury assessment data, therefore allowing to define local injury criteria. RÉSUMÉ. Un modèle éléments-finis 3D du cou humain a été développé sous le code EF Radioss afin d'explorer les mécanismes lésionnels dus à divers types de chocs. Il représente le complexe tête/cou d'un être humain du 50 e percentile assis en position de référence. Il inclut une modélisation volumique de la tête, des vertèbres cervicales, des disques intervertébraux, des muscles et tissus mous du cou, ainsi qu'une prise en compte des contacts entre les facettes articulaires et les processus épineux. Le comportement cinématique du modèle a été évalué de manière omni-directionnelle pour différents chocs. A cet effet, des résultats expérimentaux obtenus sur volontaires ou cadavres et disponibles dans la littérature ont été utilisés. Ils concernent la cinématique de la tête ou des vertèbres. La capacité du modèle à reproduire les mécanismes lésionnels a également été évaluée et comparée à des données lésionnelles expérimentales afin de définir des tolérances lésionnelles locales.

Finite element model of the human neck during omni-directional impacts. Part II: relation between cervical curvature and risk of injury

“…Bertholon et al (2000), in an experimental study, measured the relative rotations of head/C2, C2/C5 and C5/T1 during rear-end impact tests using PMHS. These experiments had been previously modelled to evaluate the reliability of the model (Fréchedè et al 2005). Simulation results, which were inside the experimental corridor in the extension phase, showed that the local behaviour of the model could be improved to fit more closely to this local motions for which regards the rebound phases (Fréchedè et al 2005).…”

“…These experiments had been previously modelled to evaluate the reliability of the model (Fréchedè et al 2005). Simulation results, which were inside the experimental corridor in the extension phase, showed that the local behaviour of the model could be improved to fit more closely to this local motions for which regards the rebound phases (Fréchedè et al 2005). Ono et al (1997), in an in vivo rear-end impact study, quantified the effect of the initial position of the head (extended, neutral and flexed) on the kinematics of the head, neck and torso.…”

Parametric and subject-specific finite element modelling of the lower cervical spine. Influence of geometrical parameters on the motion patterns

“…Simulation is a helpful tool in the orthopaedic clinical field providing the possibility to perform surgery simulations or implants evaluation (Galbusera et al, 2006;Goel and Clausen, 1998;Ha, 2006;Natarajan et al, 2000;Pitzen et al, 2002;Rousseau et al, 2008;Teo and Ng, 2001;Voo et al, 1997;Yoganandan et al, 1997). Several finite element models have also been developed to study the dynamical behaviour and injury mechanisms of the cervical spine under high G-loading or at impact (Camacho et al, 1997;Dauvilliers et al, 1994;Fré chè de et al, 2005;Halldin et al, 2000;Van der Horst et al, 1997;Yang et al, 1998;Zhang et al, 2005). However, few models enable to investigate the influence of geometrical parameters on the biomechanical response.…”

Hyper-elastic properties of the human sternocleidomastoideus muscle in tension

“…Different models of the head and neck have been proposed lately with both passive and active muscles (Brolin et al, 2005;Frechede et al, 2005Frechede et al, , 2006Hedenstierna et al, 2009;Fice and Cronin, 2012). However; muscle passive properties are based on data obtained from experiments performed on animal muscles.…”

“…However; muscle passive properties are based on data obtained from experiments performed on animal muscles. For instance, Brolin et al (2005), Frechede et al (2005) and Hedenstierna et al (2009) used data from Myers et al (1995) on rabbit muscles.…”