Computational modeling of stress development in metatarsals-on the importance of plantar aponeurosis

Abstract

Since the initial attempts, mathematical models for feet have become increasingly complex with structural and constitutive enrichments. This study investigates the effect of the plantar aponeurosis of the foot model on the predicted stress development on the metatarsals. To this end, a detailed finite element model with a skeleton, cartilages, soft tissue, plantar aponeurosis and ligaments is constructed, where the topologies of the foot and bones are defined by a CT (Computer Tomography) scan. The test scenario is a standing still, quasi-static loading condition. Results are compared to those of models without plantar aponeurosis. It is shown that, if the plantar aponeurosis is neglected in the finite element model, the predicted bending mode of the metatarsals mistakenly reverses: in the presence of plantar aponeurosis and together with the arching effect, tensile principal stresses prevail at the top of the metatarsals by a bowing out mechanism, whereas in the absence of plantar aponeurosis we observe compressive principal stresses and strains over the same region.