Matt Birk urges fellow NFL players to donate their brains - NBC Sports
Baltimore ravens matt birk hi-res stock photography and images - Alamy
Matt Birk undergoes insane body transformation losing an incredible 75 pounds since his retirement from the NFL
Former Viking star Matt Birk has started a school focused on learning over athletics – Twin Cities
Baltimore Ravens center Matt Birk retires
Baltimore ravens matt birk hi-res stock photography and images - Alamy
Super Bowl — Ravens Center Addresses Concussion Issue - The New York Times