Predictive musculoskeletal simulations reveal the mechanistic link between speed, posture and energetics among extant mammals

We challenged predictive human musculoskeletal simulations, scaled in mass from the size of a mouse (0.1 kg) to the size of an elephant (2000 kg), to move as fast as possible. Our models replicated patterns observed across extant animals including: (i) an intermediate optimal body mass for speed; (ii) a reduction in the cost of transport with increasing size; and (iii) crouched postures at smaller body masses and upright postures at larger body masses. Finally, we used our models to determine the mechanical limitations of speed with size.<br>Data and code is provided to reproduce figures 1-4Supplementary videos are available in two different formats, AVI and MP4