Reconstruction of real-world car-to-pedestrian accident using computational biomechanics model: Effects of the choice of boundary conditions of the brain on brain injury risk

In the current study, the effects of the approach for modelling the brain-skull interface on prediction of the brain injury risk are investigated using a previously validated computational head-brain model. Four types of brain-skull interface modelling approaches (1): The method used in original Total HUman Model for Safety THUMS Head-brain model, (2): Brain rigidly attached to the skull, (3): Frictionless contact between the brain and skull, and (4): Cohesive layer (springtype) between the brain and skull are employed in numerical reconstruction of a real-world car-to-pedestrian impact accident. The results indicate that the predicted brain injury risk is strongly affected by the approach for modelling the brain- skull interface. The comparison of the predicted risk of diffuse axonal injury DAI and brain contusions with the injuries sustained by the pedestrian involved in the accident seems to suggest that accurate prediction of the brain injury risk using computational biomechanics models requires direct representation of the meninges and subarachnoidal space with the CSF.