Back in 2011, 10 U of R football players were given helmets with special sensors to track the number and force of all the hits they received during the season. Researchers found the players' brains, even those that didn't suffer a concussion, did not fully heal during the 6-month break.
Doctors say this leaves players at greater risk of head injury the next season.
"It gives us some idea to figure out why some people recover and why some people don't," said Dr. Jeffrey Bazarian, associate professor of emergency medicine. "That would be a really hopeful thing for the future of football, to figure out how we get someone to recover. Is it a time thing? Or is it something else? Then we can really get a handle on how we can prevent these injuries from happening."
Doctors say they still don't know if the changes on the brain scans are bad for athletes long term.