Comparison of the THOR and Hybrid III Lower Extremities in Laboratory Testing

A comparison of the 50th percentile male THOR-LX and Hybrid III 50th percentile male dummy lower leg was conducted via component and full scale barrier testing. In the component tests, isolated THOR-LX and Hybrid III lower legs were impacted in two different test set-ups where the tibia was impacted at three different impact points. The foot without a shoe was impacted in two different test set-ups at six different impact points. A shoe impact study was also conducted to determine the effect of a shoe on the results and to determine how many impacts a shoe can withstand at each point before properties of the shoe begin to change. For these tests, the THOR-LX and Hybrid III lower legs were repeatedly impacted at four different points on the foot with a shoe. For the full scale barrier testing, the THOR-LX or Hybrid III lower legs were attached to a belted Hybrid III 50th percentile male dummy. The dummy was positioned in a compact car for each test. Each lower extremity type was tested in a left hand side 40% offset crash at 40mph and a full frontal New Car Assessment Program (NCAP) rigid barrier test at 35 mph.

This study concluded that the component testing revealed that the Achilles cable in the THOR-LX reduced the lower tibia moments about the y-axis (My) and increased the lower tibia axial forces (Fz) for dorsiflexion impacts. Upper tibia My for THOR-LX with a shoe in dorsiflexion inpacts was twice the value of My for THOR-LX without a shoe. The THOR-LX ankle reached full rotation more quickly than the Hybrid III ankle in dorsiflexion impacts contributing to the THOR-LX having higher Fz values in the lower tibia. The full scale vehicle tests showed similar performance between the THOR-LX and Hybrid III lower legs. The effects of floor pan intrusion were also evaluated.