.A series of fresh human cadaver and Part 572 dummy tests was performed under different conditions which were comparable to those of real-world accidents. A European car model mounted on a sled was used; a pair of knee-targets was fixed directly to the car body in front of the passenger knees. Test conditions are summarized as follows: human-3-pt-belted cadaver with a sled impact velocity of 50 or 65 kph; 2-pt (thoracic)-belted-cadaver with a velocity of 65 kph, the legs being positioned normally or in an oblique manner.Since the knee-thigh-hip tolerance is related to the shape and duration of the impact pulse, these interactions were the subject of a study.The tolerance to fractures depends to a great extent on the subject's bone condition. In order to predict the risk of fracture for the whole population from the tolerance found in the tested subjects, studies of mineralization and bone strength were carried out on the compact-bone-sections taken from the femurs of the tested cadavers.Tests were conducted also, using a Part 572 dummy, which enabled to predict a criterion for the knee-thigh-hip protection matched to this surrogate.Discussion of similar attempts, such as F.I.C. (Femur Injury Criterion) and K.T.H.I.C. is included.