Blast waves generated by improvised explosive devices (IEDs) cause traumatic brain injury (TBI) in soldiers and civilians. Currently, in vivo animal models are extensively used to study blast TBI, to identify mechanisms of injury, and to develop injury thresholds. This work focuses on the study of the effect of Incident Pressure (IP), skull rigidity on the measured Intracranial Pressure (ICP) and maximum principle strain measured on the skull using a validated finite element model of the rat head. Our results indicate that the ICP has a negative correlation with the skull rigidity; i.e., with increase in the skull rigidity the ICP tends to decrease. Similarly, ICP linearly increases with an increase in the IP. Finally, the strain has a negative non linear relationship with the skull rigidity.