Figure 11.5 in Rex, sit: digital modeling of Tyrannosaurus rex at rest

Figure 11.5. DinoMorph model of T. rex Stan demonstrating that the pubic shaft is sufficiently long that, with the animal's weight resting on the pubic boot, the hind limb is free to assume a broad range of positions from (A) crouch, to (B) kneel to (C) moderate extension of the hip and knee, to full leg extension when stretched behind the hips (not shown). Note that in these 3 images the tarsus is near the limit of flexion; in (A) and (B), the knee is fully flexed. Observe that the knee just clears the ground as it swings through hip flexion-extension, permitting repositioning of either hind limb while continuously resting on the pubic boot. Joint flexibility estimated in collaboration with Yoshio Ito and Kenneth Carpenter.