traumatic brain injury

Concerns about possibly incurring brain injuries have prompted Chris Borland to end his NFL career after just one season, during which he emerged as a star on the San Francisco 49ers' vaunted defense. Borland, 24, said, "I just honestly want to do what's best for my health."

Saying that he had consulted with other players, medical experts and his family, Borland stated, "From what I've researched and what I've experienced, I don't think it's worth the risk."

Flickr / skhuskies

The NCAA is suggesting that football teams hold no more than two contact practices per week during the season in guidelines that grew out of a safety and concussion summit early this year.

Practice limits were among several recommendations released Monday by the NCAA, which called them guidelines that could change "in real time" rather than rules passed through legislation.