When the NFL set up an injury video review system near the end of the 2011 season, it paid off almost immediately.

Story Highlights Independent certified athletic trainers — ATC spotters — serve as another set of eyes, watching for possible injuries at every NFL game.

ATC spotters may use a medical timeout to stop the game to remove a player for medical examination.

Teams aren’t charged for timeouts if an ATC spotter stops the game.

The league instituted the system after Cleveland Browns quarterback Colt McCoy took a helmet-to-helmet hit in a Dec. 8, 2011, contest and was sent back into the game without being tested for a concussion. The Browns said that the team’s trainers didn’t see the hit because they were tending to other players and that no one told them about it.

After the game, McCoy was diagnosed with a concussion.

“It seems inconceivable, but nobody alerted anyone,” former team president Mike Holmgren said after he met with representatives of the NFL and the players union about the incident. “So how do we do this so the doctors get the information they need? Best thing we could come up with is putting in a process to have somebody say something.”

The league responded quickly: Within two weeks, independent certified athletic trainers (ATC spotters) were in place in stadium booths at every NFL game to serve as another set of eyes, watching for potential injuries. A video component was added to the new system before the wild card playoff games on Jan. 7 and 8, 2012.

ATC Spotters: The Eyes in the Sky

In one of those games, a player took a knee to his helmet. Though the player got up quickly and managed to go to the sideline, his teammates urged the team’s trainers to check him for a concussion. He had almost completed the evaluation to reenter the game when the team's head athletic trainer checked the video, which confirmed that the player had collapsed from wooziness before getting back on his feet.

Seeing the potential benefit to player safety, the NFL permanently instituted a more sophisticated system before the start of the 2012 season.