[Redcloak]

T-rex's legs bones aren't proportioned like a sprinter's bones. T-rex's femur accounts for about half of the length of its leg...

...as compared to a cheetah...

...where the femur is about 1/3 of the leg's total length. T-rex would have a hard time getting those legs to move quickly. (In other words, he's built like an offensive lineman, not a wide receiver!)

[r9etb]

T-rex's legs bones aren't proportioned like a sprinter's bones. T-rex's femur accounts for about half of the length of its leg...

They're in roughly the same proportion as an ostrich, however, and ostriches are quite swift. It's worth noting the other similarities in skeletal structure, too.