Biofidelity Improvements to the Polar-II Pedestrian Dummy Lower Extremity

Experimental tests were performed on the modified Polar-II pedestrian dummy lower extremity components to evaluate their biofidelity in lateral impact loading corresponding to a 40 km/h pedestrian-car collision. The bending moment-angle response from a newly developed knee joint, dynamically loaded in four-point valgus bending, was compared against previously published postmortem human subject (PMHS) response corridors. In addition to the stiffness characteristics of the knee joint, individual ligament forces were also recorded during the bending tests. The evaluated force-relative elongation response of the medial collateral ligament (MCL) in the new knee was compared against PMHS data on MCL tensile stiffness. Lower extremity long bones developed for improved anthropometrical accuracy and deformability were dynamically loaded in latero-medial three-point bending. The determined moment-deflection response measured at mid-span and third-span shaft locations was compared against previously published PMHS response corridors. Finally, using a biofidelity rating system, the modified Polar-II lower extremity components were evaluated and were shown to accurately replicate the PMHS response under loading conditions similar to a pedestrian-car collision.