Researchers used an engineering technique called multibody dynamic analysis, coupled with machine learning, to produce what they say is the most accurate simulation of T-rex's gait and biomechanics to date.
But scientists have now discovered it would have been impossible for the T-Rex to run that fast without breaking its legs, due to its sheer size and weight.
While T. rex might have struggled to catch a meal, whatever it did catch stood little chance in the jaws of the king of the dinosaurs; a study published earlier this year found that a Tyrannosaurus rex had a bite force of 7,800 pounds-force (34,522 newtons) - equal to the weight of three small cars.
Researchers from the University of Manchester in the United Kingdom said that the sheer size and weight of T rex means it could not move at high speed, as its leg-bones would have buckled under its own weight load.
They created a computer model of the dinosaur and had it run at different speeds to determine what would happen.
'Here we present a new approach that combines two separate biomechanical techniques to demonstrate that true running gaits would probably lead to unacceptably high skeletal loads in T. rex'.
Professor William Sellers, who led the research team, said their findings show running would've led to "unacceptably high skeletal loads" for a T. rex.
The research also suggests that other similar sized and shaped dinosaurs - such as Giganotosaurus, Mapusaurus, and Acrocanthosaurus - may not have been able to run.
While the predator might have been easier to outrun than previously thought, the T. rex was still one of the largest meat-eating dinosaurs that ever lived. "T-rex's skeleton is simply not strong enough for running locomotion". He does, however, caution that there are other things that need to be taken into consideration with regards to the study, and that "we don't understand the principles that govern speed limits in living animals".