A new, high-speed protocol to run muscle-driven biomechanical simulations trough finite element analyses

Finite element analysis (FEA) is a computational method used to predict the behaviour (stresses, strains, and deformation) of a structure under predefined loading conditions. It can be applied to biological structures such as bone to study defined biomechanical scenarios. However, as muscle is an extremely complex structure to model, biologists usually model muscle forces indirectly. In 2007, the Boneload MATLAB routine was developed to distribute muscle forces on a surface defined by the user. This routine needs to be coupled with a pre-existing FEA software (e.g., Strand7) to perform the analyses, and has been widely used ever since. Here, we demonstrate a new method to run muscle-driven finite element simulations on bone by distributing muscle forces on their insertion areas within a single computational environment. We test this protocol on three different biomechanical systems linked to feeding and locomotion. Our automated script meshes the 3D model, applies the constraints, and distributes muscle forces within a single simulation software: Metafor. Metafor can perform the entire protocol on high resolution volumetric meshes (millions of tetrahedra) rapidly, outpacing the processing time of other widely used software by up to 12 times, all-the-while producing similar and congruent results. Our new protocol thus opens up the possibility to routinely and rapidly simulate the behaviour of high-precision, muscle-driven FE models and investigate a wide range of biomechanical scenarios at unprecedented resolution.