It’s been two years since Chris Borland hung up his cleats after playing only one season in the National Football League. The former linebacker for the San Francisco 49ers shocked the football world in 2015 when, at the age of 23, he announced his retirement, citing concerns for concussions and the long-term brain damage they can cause.
Borland’s early-retirement has become a major story in the ongoing controversy over the frequency of concussions in the NFL. Players who repeatedly suffer these injuries may have a higher risk of developing chronic traumatic encephalopathy, a degenerative brain disease caused by repeated hits to the head; the league has been criticized for not doing more to address this issue.