Figure 2.

Elastic properties of different bone regions. (a) The Young’s modulus (E_H-S) of different regions in the BMev was calculated using the Hertz-Sneddon model with fitted contact point. The central box spans the lower quartile to the upper quartile of the data. The solid line inside the box shows the median, and whiskers represent the lower and upper extremes. The mean values are indicated by black dashed lines. Data were obtained at randomly selected positions within regions of interest on bones from both young and mature mice. The Young’s modulus reported at each position is the mean value of individual fits to all force-indentation curves taken at that location. Curves with strongly tilted baselines (i.e., d_b > d_c/4, as in Document S1. Supporting Materials and Methods and Figs. S1–S10, Document S2. Article plus Supporting Material) were discarded. Results from low quality fittings (i.e., R² < 0.9) were also discarded. The significance of statistical comparisons using the Kruskal Wallis method have been indicated above each group of boxplots (^∗∗∗p < 0.001). (b) Histograms of the E_H-S of different bone regions, as in (a). The corresponding histograms in linear scale are presented in Fig. S2. Data were collected from at least n = 17 mice (cortical bone n = 18, growth plate n = 19, metaphysis n = 20, and bone marrow n = 17 mice). To see this figure in color, go online.