Strain gauges used in the mechanical testing of bones. Part III: Strain analysis, graphic determination of the neutral axis.
The problem addressed in this part is the analysis of the strain pattern within the bone, when the strain has been measured using strain gauges along the long axis of the diaphysis of a bone subjected to axial load, bending, or eccentric axial load. It is first necessary to obtain the position of the strain gauges using, for instance, computed tomography. The linear bending theory is then used to determine graphically the position of the neutral axis in a cross section and the strain field within the bone. An example of application is taken from the literature: Rybicky et al. (1) measured the reduction of strain within a plated horse metatarsus, relative to that of the intact bone. They made an analytical strain analysis. A comparison is made between the analytical results and the graphic ones, validating the graphic method.
Cordey
J
J
AO ASIF Research Institute, Davos, Switzerland.
Gautier
E
E
D001698:Biomedical Engineering / Q000295:instrumentation* / Q000379:methods; D001860:Bone Plates; D005264:Femoral Fractures / Q000503:physiopathology*; D005269:Femur / Q000503:physiopathology*; D005592:Fracture Fixation / Q000295:instrumentation / Q000379:methods; D006801:Humans; D008422:Materials Testing; D012106:Research; D013314:Stress, Mechanical