This paper traces important features In human knee design that allows the unique function of plantigrade bipedalism (walking two legged on the soles of the feet). Concepts of biomechanlcal importance related to human gait and the problem of knee flexion contracture are discussed. Alleged hominid ancestors would have had to overcome a flexed knee stance to become efficient bipeds. Knees discovered In the fossil record, however, are fully functional. Joint replacement research has carefully followed a reproduction of the original design for a most unique Joint - the human knee
