Figure 11.10 in Rex, sit: digital modeling of Tyrannosaurus rex at rest

Figure 11.10. Elevation of the posterior while anchoring the anterior body by the forelimbs, creating a pose much like a sprint start. The mechanical advantage of a secondclass lever is provided during extension of the hind limbs in raising the COM. With sufficient elevation achieved, the animal could push back and regain bipedal balance, and complete its ascent to a standing pose.