Torsional tests of long bones with computerized equipment.
An experimental method using a computerized torsion machine to study the mechanics of entire diaphyseal bones is described. Besides controlling continuous torsion to ultimate fracture of the bone, the computer is able to use non-linearity of the torque-twist curve as a criterion for reversal of the direction of torsion and to control repeated loadings and unloadings with a graduated increase of deformation until final fracture. It permits determination of a small residual deformation, and several other parameters characterizing the load-deformation curve. The linearity of the equipment is shown to be good and precision is high, with a method error of 2.3% when determining stiffness. Repeated loadings and unloadings of entire dog femora revealed a minor residual deformation before ultimate fracture.
D001696:Biomechanical Phenomena; D001698:Biomedical Engineering; D001842:Bone and Bones / Q000502:physiology*; D003201:Computers; D006801:Humans; D013314:Stress, Mechanical