Current finite element (FE) models of the human body do not properly include the contribution of the intercostal muscles (ICM), which is believed to limit their rib fracture prediction capabilities. In the present study, an existing full body model for a seated 50th-percentile male was evaluated under five cases of loading: point loading of the denuded ribcage, frontal pendulum impact tests, lateral and oblique pendulum impact tests and table top tests. The sensitivity of the model to changes in material model of the ICM was evaluated by using two material models: an isotropic linear elastic material model and a foam model defined by a single uniaxial load curve extracted from a recent literature. The performance of these models compared to the experiments was assessed quantitatively through a correlation analysis on the force and chest deflection time histories. The simulations found that that the material properties of the ICM have little effect on the externally measured impact force and chest deformation except in point loading.