Fig. 6. Mean peak bone strains versus body mass for the emu TBT on logarithmic axes. Mean peak axial tensile and compressive strains for the (A) cranial and (C) medial surfaces and (B) mean peak principal tensile and compressive strains from the caudal surface of the emu TBT while the birds ran at a 0.40DF. Tensile strains, circles; compressive strains, squares. In A, the equations for the least-squares regression lines for the peak axial tensile and compressive strains are y=179x^0.21±0.28 (R²=0.11, N=19) and y=–165x^{–0.324±0.316} (R²=0.09), respectively. In B, for principal tension, y=400x^0.26±0.11 (R²=0.68, N=12) and principal compression, y=–500x^{–0.32±0.10} (R²=0.75). In C, for axial tension, y=144x^0.15±0.25 (R²=0.09, N=18) and axial compression, y=–542x^{–0.12±0.17} (R²=0.08). The slopes and 95%CIs of the power lines for the compressive strains, were taken on the absolute values of these strains, but plotted in the figure on the negative compressive values for clarity. As multiple trials at this DF were not collected for all birds, error bars have been omitted for consistency.