As head-injury research improves, the NFL continues to try to make an inherently dangerous game safer. The league and the players' union have implemented a game-day concussion protocol, which includes immediately removing players from the field at the suspicion of a potential concussion.

It's not a perfect system but it's an important step in player safety. But Donald Trump thinks the NFL has gone "soft" with its concussion rules.

At a campaign event in Lakeland, Fla., on Wednesday, the Republican presidential nominee witnessed a woman fainting in the audience. Trump asked for a doctor, and then assured the crowd that the woman would return to the rally.

After treatment, the woman did return, which prompted this from Trump, via the Washington Post: "That woman was out cold, and now she's coming back. See, we don't go by these new, and very much softer, NFL rules. Concussions -- 'Uh oh, got a little ding on the head? No, no, you can't play for the rest of the season' -- our people are tough."

Michael Kaplen, a George Washington University Law School professor specializing in brain injury, told the New York Daily News that Trump's comments were reckless.

"Donald Trump, in a matter of seconds, has managed to disparage each and every one of these individuals," Kaplen said. "This just demeans and disparages people with brain injuries, and disparages the whole movement of concussion awareness, concussion protocol.

"All concussions are brain injuries with potential lifelong consequences. It's tragic the way a candidate for the highest office talks about this devastating injury. A brain injury is not a joke."

In 2015, there were 271 documented concussions in the NFL, a 32 percent increase from the year before when there were 206.