The choice of a human body model for a simulated automotive impact scenario must take into account both accurate model response and computational efficiency as key factors. This study presents a "modular numerical human body modeling" approach which allows the creation of a customized human body model of a 50th percentile male (size and weight), where the various body parts are modeled with different levels of complexity (multi-body and finite element) and can be easily swapped depending on the application. Implementation of this modeling technique has been performed by modularizing the MADYMO facet human body model, with focus on the pelvis and legs. Two component models have been attached: (1) a detailed facet pelvis and leg model of increased complexity, and (2) a full finite element pelvis and leg model. All models were subjected to various pendulum impacts for validation of the modular components and analysis of the resulting computational benefits. Copyright © 2007 SAE International.