Four human hip joints which had been fixed informaldehyde taken from human corpses (average age at death: 72 years) were subjected to pressure along defined axes and tested for static strength and elasticity, the hip joint being regarded as a system. The stress-strain curve reveals no definite linearity. The deviations from Hooke's elasticity found in this way have been explained by the fact that not only completely elastic bone, but also plastic components (cartilage of the joint) were tested. The maximum breaking strain, the modulus of elasticity and the elasticity coefficient were also determined. Only about 50% of all fractures observed on the test set-up were diagnosticised radiologically. The parameters which have, in the past, been determined only on models have thus been replaced by experimental results obtained on actual hip joints.