It is of considerable interest to developers of military vehicles, in early phases of the concept design process as well as in Analysis of Alternatives (AoA), to quickly predict occupant injury risk due to under body blast loading. The most common occupant injuries in these extremely short duration events arise out of the very high vertical acceleration of vehicle due to its close proximity to hot high pressure gases from the blast. The primary objectives of this paper are to conduct an extensive parametric study in a systematic manner so as (1) to determine if a single blast loading parameter is sufficient to adequately characterize the occupant injury, at least for the duration of typical blast events (0-20ms) and (2) to create look-up tables and/or an automated software tool that decision-makers can use to quickly estimate the different injury responses for both stroking and non-stroking seat systems in terms of such a parameter.