Figure 3.

Hypotheses and results, schematic summary. RMA scaling factors (red or blue arrows; F: forepad; H: hindpad; n = 10 adults) were (a) obtained empirically for m-p pad compressive stiffness (each is shown here with its CI; see the electronic supplementary material, table S1.3), or (b) derived algebraically for the modulus, strain, strain energy density, total deformation and strain energy storage of the pad as indicated in the electronic supplementary material, §1. Calculations were obtained for each pad under the load to which it would be subjected when the animal is standing. Each result is compared to the predicted ranges of values for the proposed hypotheses (green dot or bar; ranges of green bars span values given in table 2, which as noted there were obtained using different regression models and assumptions) for fore (upper bar of each pair) or hind (lower bar) pads. Results (see also table 4) indicate that stiffness of forepads scales directly with body mass (t-test: p ≫ 0.5; H4 accepted), but that of hindpads has a scaling factor between and overlapping predictions made by both H3 and H4.