Academics from the University of Leicester said the bones of the last Plantagenet king were placed in an odd position and the torso crammed in.
He was casually placed in a badly prepared grave, suggesting gravediggers were in a hurry to bury him or had little respect for the murdered king.
The lozenge-shaped grave was too short for the body and there is evidence to suggest his hands might have been tied when he was buried.
Researchers said someone is likely to have stood in the grave to receive the body, suggested by the fact the body is on one side rather than placed centrally.
The findings were revealed as University of Leicester archaeologists published the first peer-reviewed paper on the university-led archaeological Search for Richard III in the journal Antiquity.
It comes after the announcement in February that the monarch's remains had been discovered.
There were no signs of a shroud or coffin, in stark contrast to other medieval graves found in the town that were the correct length and dug neatly, academics said.