For several years, the National Football League has been at the center of conversation about concussions and chronic traumatic encephalopathy (CTE).
It's an issue that extends well beyond the NFL, however, and hit close to home for Colorado running back Phillip Lindsay recently.
On Sept. 16, Lindsay had the opportunity to play against his younger brother, Zachary, a running back at Northern Colorado. It was the only time they ever played against each other. Four days later, Zachary announced on Twitter that he was leaving UNC and the game.
In a follow-up tweet, Zachary said, "I have to. to many concussions" (sic).
For Phillip, it was a personal reminder of the dangers he, his brother and other players face every time they step on the field.
"When it comes down to it, your head is nothing to play with," he said. "I've seen it personally that it can change people and it's scary. It's really scary.
"Any time you deal with concussions, and you've seen it with the CTE and everything going on and it causes mood swings and causes anger and stuff like that, it's scary. It is. It makes you feel like, 'Dang, hopefully you don't have it.'"
Phillip didn't want to go into details about his brother's situation, but applauded Zachary for making the decision to walk away.
"He needed to look himself in the mirror as a man and understand when enough is enough," Phillip said. "No matter what, whether you go to the next level or not, one of these times is going to be time for you to go. Regardless, you're going to get forced out (of football). Health matters more than football."
For now, CTE can only be diagnosed after death, and it has been detected in the brains of several former NFL players. It can take several years after an athlete stops playing for symptoms to occur.
While the NFL is in the spotlight on this issue, athletes at all levels experience concussions.
"Right now, they're talking so much about the NFL because they're on the bigger stage," Phillip said, "but think about all the kids right now that are going through that. Think about all the kids that probably already have it right now that we don't know about."
As a running back, Phillip's body goes through a pounding on nearly every play. He also pointed out the constant pounding taken by offensive lineman and linebackers.
Despite that, Phillip said he has never gone into a game thinking about potential injuries.
"I go out there and play my hardest every snap and every play and I pray every day for God to keep me as healthy as I can be, or as he can keep me at the time," Phillip said. "That's all you can do. We're playing a sport that involves you getting hit in the head, it involves you getting hit in your knees. It's just how it is. It's a barbaric game, but it's your attitude towards it.
"We all signed up for this. It's something that you choose to do. I choose to do this, and when it's time for me to stop, that's when I'll be done with it."
Zachary made the decision to be done with football, and Phillip knows that at some point he'll have to make that decision, as well.
"If it's concussions or any type of injury that I feel like it's time for me to move on, I'm going to do what's right for me," he said.
"I'm happy (Zachary) was able to make the decision for himself. I think he'll be in a better spot now."
While he's sad to see his brother give up the game he loves, it brings a smile to Phillip's face to know he shared the field with Zachary for his last game.
"It was a special moment that will always be cherished for the rest of our lives," Phillip said. "It's a symbol of the next chapter for both us."