Cadaver and Dummy Knee Impact Response

Knee impacts along the femoral axis of unembalmed male cadavers and Part 572 dummies were made with rigid pendulum impactors at Wayne State University. The dummy exhibited significantly higher knee impact forces than the cadaver subjects. This difference of response is shown to be due to differences of effective leg mass and knee padding. The dummy with its heavy rigid metal skeleton is not like its human counterpart, where the majority of the leg weight is composed of loosely coupled flesh.

The knee impacts of the dummy subjects showed that the dummy femur transducer force was consistently less than the corresponding dummy knee impact force by a constant ratio of 0.8.

We recommend that the “skeletal” weight of the Part 572 dummy leg should be substantially reduced, with the weight difference being added to a properly simulated leg flesh. Also, the simulated flesh covering of the knee should be modified to reduce the peak force resulting from rigid body impacts.