For Aynsley Smith and Dr. Michael Stuart, the tipping point came two years ago. The Mayo Clinic colleagues were dealing with an ever-growing number of hockey players affected by concussions, and they were seeing more and more evidence that such injuries were becoming a widespread issue in sports.

"We thought, 'My gosh, we have to do something,''' said Smith, research director for Mayo's Sports Medicine Center. To tackle the problem, they combined Minnesota's most beloved game with one of its greatest institutions. "The Ice Hockey Summit: Action on Concussion," a two-day conference that ended Wednesday at the Mayo Clinic, brought together an unprecedented array of like-minded people to address one of the hottest topics in sports.

Among the participants were medical professionals, researchers, equipment manufacturers, coaches, officials and hockey administrators, including many of the nation's foremost experts on concussions. They left Rochester with a plan to create change through study, education and advocacy.

Many sports leagues, including the NFL and NHL, have begun to recognize the serious damage concussions can cause. Increasing evidence of the toll -- including studies that link debilitating neurological conditions in retired NFL players to repeated impact to the head -- have led the NFL to issue new rules on hits to the head, as well as more restrictive policies on when athletes can return to play after concussions.

The suggestions proposed at the Mayo summit include a total ban on contact with the head, at all levels of hockey; mandatory education of coaches, parents, referees and physicians about how to recognize, treat and prevent concussions; and prohibiting athletes from returning to play until they are cleared by a doctor. When the conference ended, many participants pledged to keep working together, which is exactly what Smith and Stuart hoped.

"Change is not going to happen overnight,'' said Stuart, co-director of the Mayo Clinic Sports Medicine Center and chief medical officer for USA Hockey. "At the same time, the clock is ticking. If we say we need additional long-term injury research to validate any recommendation, there will be a lot of athletes who will suffer in the interim.''

Smith knew she was on to something when she received an immediate, enthusiastic "yes'' from the first speaker she invited. She and Stuart wanted all recommendations coming out of the summit to be based on scientific evidence, and most of the 40 presenters cited studies that underscored the seriousness and urgency surrounding the issue.

Many focused on the science of concussions. Research discussed at the event showed that young, developing brains take longer to heal, meaning treatment must be tailored to specific ages. Cognitive exertion, such as going to school, can delay recovery just as physical exertion can. Even after symptoms subside, the brain may not be fully mended, and it is vulnerable to further damage if an athlete returns to play too soon. Women seem to be more susceptible to concussions than men, though the reasons are unclear.

Other presentations showed that athletes can take steps to prevent concussions, such as strengthening the neck muscles and heightening awareness on the ice. But there are roadblocks, too.

Kevin Guskiewicz of the University of North Carolina said that 50 percent of concussions in high school football players may go unreported, and 75 percent of athletes do not know the signs and symptoms. Many athletes fear they will be stigmatized or demoted if they admit to being hurt, so they lie about their condition. Longtime NHL referee Kerry Fraser decried the lack of consistency in enforcing rules regarding dangerous hits, and former North Stars defenseman Jim Johnson -- who has coached youth hockey -- told of being confronted by an angry parent when he wouldn't play an injured boy.

"We have a culture in this game that needs to be changed,'' Fraser said. "The rules are in place. We just need to enforce them. ''

Dr. Ann McKee, part of the team that is researching severe neurological conditions in former NFL players, showed graphic evidence of how destructive concussions can be. A photo of the brain of former Viking Wally Hilgenberg -- who suffered memory loss and confusion before ALS took his life -- bore the signs of damage caused by repeated trauma.

In the coming months, a group of summit participants plans to advocate for change by publishing articles and posting material on YouTube and other websites. They are considering developing their own site with information for people who are recovering from concussions, and they expect to organize another conference.

"We understand the work is just beginning,'' Stuart said. "It's going to take a concerted effort from a lot of people to reach our goal. But we've fostered a partnership that crosses continents and disciplines. It truly is a unified effort to make a difference.''