The film also looks closely at the efforts of researchers led by Ann McKee at Boston University's Center for the Study of Traumatic Encephalopathy, where the brains of a number of former NFL athletes have been examined.

"[13] Frontline in 2010 produced a documentary on health issues in youth sports with a focus on repeated concussions and subconcussive blows in high school football.

[15] Response to the documentary was positive, with many reviewers commenting on how powerful it was, and how it may change their views of football going forward, although noting that much of the information had been written about or shown before.

"[19] USA Today wrote "if this documentary made even a sliver of the league's fans, personnel and fellow media stop and reflect for a few hours Tuesday night, it was well worth the exercise.

"[20] The New York Times said "The program doesn't give the league much credit for recent rule changes and other safety initiatives, instead underscoring its continuing reluctance to acknowledge a link between the sport and brain injuries and its reliance on language that pushes any day of reckoning into the future."

and "Much of this has already been reported, with Alan Schwarz of The New York Times often leading the way, but the program will certainly be eye-opening for anyone—especially parents with children of Pop Warner league age—who hasn't followed the subject closely or seen The United States of Football, a documentary released in August.