PYEONGCHANG, South Korea (AP) - At the bottom of the Olympic aerials landing hill, where crashes are common and the term "slap back" is part of the everyday lingo, skiers spend almost as much time figuring out how to protect their heads as they do working on all those flips and spins.
"We learn how to fall," U.S. jumper Jon Lillis said.
Elsewhere around the action-sports venue, that's not so much the case.
Concussion dangers lurk everywhere - from the iced-over deck of the halfpipe, to the steeply pitched landings on the slopestyle course, to the careening twists and turns of the snowboardcross track, to the aerials course, where "slap back" is the term for when a skier's head slaps backward against the snow. But at the Olympics, there are no hard-and-fast rules regarding who diagnoses head injuries, and no hard-and-fast protocol that athletes must clear to be allowed back on the slopes after a concussion.
"A bit concerning," says neurologist Kevin Weber of the Ohio State Wexner Medical Center. "Because you worry that athletes in other sports that may not be as popular as football are getting, I wouldn't say ignored, but the concussions they're getting are under-scrutinized."
The most telling example of this came Saturday in the women's ski slopestyle contest, where silver medalist Mathilde Gremaud of Switzerland described a training accident in which she hit her head, lost her memory and dealt with lingering headaches the next day. Her description was followed quickly by an explanation from the Swiss team doctor, who said Gremaud checked out free of concussion symptoms and was cleared to compete the day after the wreck.
"The idea that she overcame what appeared to be a concussion and raced 36 hours later and won silver is not a feel-good story," said Chris Nowinski, founder of the Concussion Legacy Foundation. "I think it's a 'Thank God She Survived' story. It's a shame she was out there."
The NFL has come under withering criticism for its handling of concussions over the decades. It has tried, not all that successfully, to strengthen its protocol. Neurologists independent of the teams are required to be at every game, and players are supposed to go through a strict battery of tests before they're allowed back on the field.
That system has failed the players time and again, yet for all its weaknesses, it appears a fuller and better-thought-out plan than what's in place for the International Ski Federation (FIS), which runs all the ski and snowboard events at the Olympics.
FIS has a 12-page booklet with thorough instructions on how to diagnose concussions. But ultimately, team doctors are given authority to clear their athletes. A FIS spokeswoman said it wasn't practical to have independent neurologists at the wide array of events it conducts each weekend during the winter.
The IOC, which has ultimate authority over the Olympics, said its protocol is based on a 2016 medical paper that was compiled by more than 20 experts and represents best practices that are recommended to the individual sports federations. The paper notes the importance of neurological evaluations but doesn't recommend those evaluations be done by an independent doctor.
"It can set it up for some awkward situations" in which team doctors who are close to the athletes have to make decisions about their availability, Weber said. "But it's no different from the overwhelming majority of sports, where it's the team physicians who are the ones evaluating for concussions."
This is hardly a new topic for world-class skiing and snowboarding.
A FIS study of all its disciplines - Alpine, freestyle, snowboarding, ski jumping and cross-country - found that about 10 percent of the 3009 injuries charted from 2006-16 involved concussions or neurological damage.
"It's definitely prevalent," American Alpine skier Ted Ligety said. "Guys are taking high-speed falls. It's something we're all aware of."
Some of the biggest stars in snow sports have had some of the worst injuries. The story underlying Shaun White's gold medal last week was his comeback from a massive crash during training in October that split his lip open and required 62 stitches to repair. Iouri Podladtchikov, the 2014 Olympic halfpipe champion, missed the Pyeongchang Games because of a scary fall he took in a competition a few weeks earlier.
The death of halfpipe skier Sarah Burke and the brain injury suffered by snowboarder Kevin Pearce stand as the seminal warnings about the dangers of these sports.
While it's hard to predict where most of the injuries might come in most of their runs, the point of impact is the same on an aerials course, where there is a single landing hill that is stacked with loads of cushy snow to try to dampen the impact.
Lillis, the aerialist, said team doctors are an athlete's best line of defense, and "you depend on the medical staff to not put you in jeopardy."
But the doctor isn't their only line of defense.
"If you hit your head, you have to be honest," he said. "Ultimately, if you're not, that's on you. The athlete has to, at all times, hold some of the responsibility."
AP Sports Writer Pat Graham contributed to this report.