Differences in biomechanical properties of cortical bone with age. From the three-point bending of whole long bones, the fracture displacement tended to be higher for young rats than the aged F344 male rats (a). The estimated material strength in bending was higher or did not change with age when the radius was tested, but was significantly lower for the 24-mo. rats when the femur was tested (b). In contrast, there was an increase in brittleness with advanced age for the radius, whereas post-yield toughness was modestly lower at 12-mo. and 24-mo. than at 6-mo. of age in the femur (c). The outlier, marked as red-filled circle, was not included in the statistical analysis. *p<0.05 vs. 6-mo. and #p<0.05 vs. 12-mo.