T-Rex suffered from arthritis.
T-Rex suffered from painful back and knees
Experts have found signs that the dinosaurs were likely to have suffered from pain in their back and knees as they were "blighted by bone diseases".
Fossils demonstrated evidence of fused vertebrae and strange growths on the leg bones of three theropods that were dug up in South America.
This means the prehistoric predators could have been left hobbling in pain, just as afflicted humans do.
Back and hind legs were the main issues for the dinosaurs but they also had bone damage in their jaws and arms.
Study author Dr. Mattia Baiano, from the National University of Rio Negro in Argentina, said: "A large number of the theropod specimens have evidence of some type of malady.
"Damage in weight-bearing bones would hamper the feeding activities or would leave them an easy target for predators."