America's most popular sport, football, takes on its toughest foe, brain trauma

Buddy Teevens had a vision. The Dartmouth College head coach wanted to shed a football way of life ingrained through numerous head-bashing Oklahoma drills. But only after he asked his players to stop tackling each other following a 2-8 season in 2009.

"The guys thought I was kidding," Teevens said. "But I just thought it was the right thing to do, and I also thought we could protect our players."

America's most popular sport was slowly being connected to CTE, or chronic traumatic encephalopathy, a brain disease linked to repetitive hits to the head. And Teevens was paying attention. He coached Dan Rooney, the great-grandson of Pittsburgh Steelers founder Art Rooney, and knew well the story of Mike Webster, the Super Bowl-winning center for the Steelers who ended up homeless while suffering from amnesia and dementia before his death of a heart attack at age 50 in 2002.

So as Sunday's Super Bowl at U.S. Bank Stadium looms, it's fair to ask about the future of the game.

Many, like Teevens, are trying to create a safer future underneath the ripples caused by brain injuries.

An important change started with a robot deployed in August 2015.

Teevens funded a graduate research project now called the Mobile Virtual Player, or MVP, a remote-controlled robot resembling a traditional tackling dummy that moves forward and backward and side to side. Nearly half of all NFL teams now use the MVP in practices to prevent injury. Twenty-seven college programs and 19 high schools have also bought into the new-age tackling apparatus in the 29 months of its existence.

Football's safety is an ongoing debate. Parents are left to decide whether to let their children participate as the medical community churns out groundbreaking research, not all of it conclusive. Dr. Bennet Omalu, the forensic pathologist chronicled in the 2015 movie "Concussion," is credited with making the first link between football and CTE in 2002 after his autopsy of Webster. But his discovery didn't hit mainstream until after years of resistance from the NFL.

Now the dangers of football are widely publicized. Former players have expressed their concerns. Hall of Fame quarterback Brett Favre debuted a concussion documentary in January titled "Shocked: A Hidden Factor in the Sports Concussion Crisis." Favre cites the turf — especially the old, less forgiving kind — as a cause for "most" of his brain injuries through his NFL-record 297 consecutive starts. In the last game of his career, he suffered a concussion on the frigid field at TCF Bank Stadium in 2010.

"I got three grandsons," Favre said on "The Rich Eisen Show" while promoting the documentary. "I'm not going to encourage them to play football. I'm not going to discourage them, but I would much rather be their caddie for them in golf than watch them play football."

The danger is about more than concussions, says Chris Nowinski, a former Harvard defensive tackle who founded the Concussion Legacy Foundation and authored the book "Head Games: Football's Concussion Crisis." Repetitive hits, even those not causing documented concussions, are being linked to brain damage and CTE.

"It's absolutely still a crisis," Nowinski said. "Now it's a concussion and CTE crisis."

The latest study comes on the heels of this summer's stunner in the Journal of the American Medical Association, which found signs of the neurological disease in 87 percent of 202 brains donated from deceased high school, college, semipro and professional football players. Only one of the 111 brains donated by deceased NFL players did not show signs of CTE.

After years of cold-calling families of deceased players to request brain donations, Nowinski is now taking aim at the nation's youth. He's calling to end tackle football for kids ages 13 and younger. Nowinski and Boston University researchers launched the Flag Football Under 14 education initiative in January, partnering with four-time Pro Bowl linebacker Phil Villapiano and Hall of Famers Nick Buoniconti and Harry Carson. Buoniconti, 77, has been diagnosed with dementia and probable CTE, a condition not yet easily diagnosable in living brains.

Parents already have taken notice.

Vikings defensive end Everson Griffen and his wife, Tiffany, welcomed the couple's third child this fall: Sebastian Gregory Griffen. But Sebastian will have to wait until he's at least in high school if he wants to play his dad's sport.

"I will allow them to play," Griffen said. "But they won't play until like freshman year of high school. I'm going to hold them back and let them play baseball, soccer and basketball."

Minnesota had more than 32,000 high school kids on the gridiron during the 1999-2000 seasons; last year the number was 23,170.

"The brain is a sensitive area," Griffen said, "so I want the least contact possible."

Dr. Uzma Samadani, a neurosurgeon and parent to a high school football player, is more concerned with brain trauma and its myriad effects than CTE, which is a "very, very confusing condition," she said.

"One has to be very cognizant of the risks of subconcussion," Samadani said. "That's something that's been very heavily investigated in the media, but it's something I think that is poorly understood."

Samadani is an ally to football, as an associate professor in the department of neurosurgery at the University of Minnesota and attending neurosurgeon at Hennepin County Medical Center. While some doctors call for schools to eliminate football, she instead is focused on preventive measures for all brain trauma. Further research is needed to better understand CTE, she said.

She advises parents to put children in "as safe of a sport as possible," pointing to football's benefits for heavier or asthmatic children who might not be able to participate in fall sports such as cross-country or basketball.

More awareness is helping to fortify the NFL's lifelines from Pop Warner football to high school and college.

Hydration is at the forefront, helping to prevent heat stroke. Equipment has improved. Rules are now geared toward reducing high-speed collisions, such as on kickoffs. Each level is trying to reduce helmet-to-helmet hits, once celebrated in the mainstream through ESPN's previously popular "Jacked Up!" segment. USA Football's Heads Up program, partnered with the NFL, preaches proper technique.

Football coaches and players don't often welcome change. The sport's evolution isn't happening overnight.

Players prioritize their own comfort and, subsequently, their performance. Vikings defensive end Brian Robison happened across a safer helmet — a Schutt model, which includes cutout plates in its outer shell that move independently from the rest of the helmet — simply because "it fit well."

Schutt and Riddell have long been the primary suppliers for the NFL, but new helmet manufacturers are pushing the standard of safety. That's where Vicis, makers of the NFLPA's top-testing Zero1 helmet, are starting to carve out a niche among safety-conscious NFL players.

Only roughly 3 percent of NFL players wore the Zero1 in 2017, Vicis' first on the market. But Vicis, which was started with a $1.1 million grant in 2015 through the NFL's Head Health Challenge, gained both prominent wearers and investors in Seahawks quarterback Russell Wilson and Chiefs quarterback Alex Smith, among others.

You might not have noticed. The Zero1 doesn't look much different from other helmets, save for a wider facemask giving better peripheral vision, but its difference is noticed on impact.

"Helmets usually have a hard outer shell like cars from the '50s or '60s," Vicis top executive Dave Marver said. "When you got into a collision, the body of the car wouldn't yield. There was no crumple zone. Whereas our helmet has an outer shell that does deform or yield like modern cars."

The outer shell of the Zero1 bounces back "in milliseconds," Marver said, taking some of the impact away from players' brains.

"Mouth guards are the best way to couple with the head," Miller said. "The engineers are interested in what the head sees, not what the helmet sees. It's an important difference to an engineer, because you're going to get a much more accurate reading."

Miller is aiming for a "pilot-sized rollout" of its mouth guard censors in the NFL by 2019.

More data will drive innovations inside and outside the league, where the Zero1 helmet and Teevens' MVP robotic dummy are helping to drive the future of football. The NFL is also observing further safety measures being taken in the college ranks and Canadian Football League.

Dartmouth eliminated full-contact tackling in practice in 2011. The rest of the Ivy League eventually followed. Last fall, the CFL barred players from hitting one another during regular-season practices. The NFL has no such ban but since 2011 has limited teams to 14 regular-season padded practices.

Teevens said Dartmouth's documented concussions in practice dropped by 80 percent, though its players were still "tackling more than anybody in the country," just not each other. He's taking his progressive approach to other coaches. Teevens spoke at the American Football Coaches Association Convention in Charlotte, N.C., earlier this month, where he continued trying to convert skeptics from Pop Warner to NCAA.