How are loads in the pedestrian struck side leg affected by boundary conditions in Human Body Model simulations?

Several developments of biofidelic subsystem impactors for pedestrian testing have been presented in the past, with the purpose of minimising the lower extremity injury severity in pedestrian accidents. The flexible pedestrian legform impactor (FlexPLI) shows higher biofidelity compared to the European Enhanced Vehicle-Safety Committee (EEVC) pedestrian legform impactor [1]. Due to the missing upper body mass the FlexPLI cannot adequately simulate the bending load generated on a lower limb of pedestrians for specific vehicle geometries [2]. The advanced pedestrian legform impactor (aPLI) with a supplementary upper body mass (SUBP) was developed to address this issue [2]. The aPLI was developed (and thus correlates well) with the JSAE Human Body Model (HBM). It would appear sensible to re-evaluate the approach by employing another HBM and another generic test buck and by applying varying boundary conditions. The current study aims to answer the following questions: (1) What is the effect of varying boundary conditions (like impact height, leg length and mass, contact with non-struck side leg, Isolated leg with simplified upper body mass, etc.) on the pedestrian leg loads? (2) Is the SUBP developed by [3] transferable to another HBM?