T-Rex couldn't run. Doing so would have broken its legs.

In a study published in Peer J Tuesday, a team from the University of Manchester, U.K., demonstrated how a T-rex would move. They used two separate biomechanical approaches to create a computer model simulating how T-Rex would run, if it could. Because their model combined different aspects of bodily analysis, including the stress placed on the skeleton and how its body would move anatomically, the team believe the picture produced is a more accurate depiction of T-Rex’s gait.

Their findings show that not only was the species unable to run, but it could not even walk very fast. If it were to run, it would have buckled under its own weight and broken its legs, they found. They believe T-Rex’s maximum speed peaked at around 7.7 meters per second, or just over 17 miles per hour (mph). To put that in perspective, Usain Bolt, during the 100-meter sprint, has clocked speeds of over 27 mph.