Improvised explosive devices (IEDs) and anti-vehicular (AV) landmines targeted United States military vehicles throughout the conflicts in Iraq and Afghanistan. Injuries sustained by the occupants of these vehicles are severely debilitating and difficult to treat. The occupant’s feet are usually in contact with the vehicle floor making the lower extremity highly susceptible to injury during an under-body blast (UBB). Therefore, vehicle improvements must be made to effectively mitigate the extreme forces of an UBB event so they cause minimal harm to the occupant. It has been proven that current anthropomorphic test devices (ATDs) such as the Hybrid-III are inadequate when it comes to accurately measuring the response of the human to blast loading. Therefore, a new dummy, called WIAMan (Warrior Injury Assessment Manikin) is under development. The main objective of this study was to validate the unbooted WIAMan lower limb FE model so that it can be incorporated into a whole-body model of the ATD. A numerical model of the dummy lower extremity was developed for LS-DYNA by a multi-institutional research team. Material models in LS-DYNA were generated for the soft parts of the dummy based on high and low strain rate data. The WIAMan FE model was simulated under identical conditions as the experiments done on the physical dummy. A comparison between the outputs from the simulation and the test data was used to validate the unbooted WIAMan-LX model. To assess the biofidelity of the dummy and demonstrate the limitations of automotive ATDs, a comparison between the WIAMan, Hybrid-III and PMHS tests was also done.