Transmission of force to the hyoid bone during manual strangulation: Simulation using finite element numerical models.

ABSTRACT

INTRODUCTION: Strangulation is a medicolegal form of mechanical asphyxia, and can be difficult to identify if cutaneous damage to the neck is limited. We began by creating a numerical model of a hyoid bone with adjustable anthropometric parameters and then subjected our model to compression simulating a precision grip on the neck from the front. MATERIALS AND METHODS: We selected six bones from the 77 hyoid bones contained in the database we created during a previous study led by our laboratory, in which we demonstrated the sexual dimorphism of this bone and identified the minimal force required for fracture. The anthropometric characteristics of these six bones (angle, length and width) corresponded to those of the 10th, 50th and 90th percentiles from cluster 1 (male individuals) and cluster 2 (female individuals), respectively. After enhancing, developing and meshing the selected 3D models, we analysed and reproduced simulation conditions that were as close as possible to the in vivo conditions of neck strangulation from the front (area of pressure on the bone, tissue environment, and biological variability of this bone). RESULTS: We modelled the six numerical hyoid bone models using the finite element method. For all models, the simulation of mechanical pressure applied to simulate anterior strangulation resulted in fractures. The forces required to produce these fractures matched the results obtained in the experimental testing of dissected hyoid bones. CONCLUSION: Six finite element numerical models were created, covering the anthropometric morphological variability of the hyoid bone. These six models enabled numerical simulation of the in vivo behaviour of a hyoid bone subjected to one-handed strangulation.