CHICAGO >> The NCAA agreed Tuesday to settle a class-action head-injury lawsuit by creating a $70 million fund to diagnose thousands of current and former college athletes to determine if they suffered brain trauma playing football, hockey, soccer and other contact sports.

College sports’ governing body also agreed to implement a single return-to-play policy spelling out how all teams must treat players who received head blows, according to a Tuesday filing in U.S. District Court in Chicago. Critics have accused the NCAA of giving too much discretion to hundreds of individual schools about when athletes can go back into games, putting them at risk.

Unlike a proposed settlement in a similar lawsuit against the NFL, this deal stops short of setting aside money to pay players who suffered brain trauma. Instead, athletes can sue individually for damages and the NCAA-funded tests to gauge the extent of neurological injuries could establish grounds for doing that.

The filing serves as notice to the federal judge overseeing the class-action case that the parties struck a deal after nearly a year of negotiations. In addition to football, ice hockey and soccer, the settlement also applies to all men and women who participated in basketball, wrestling, field hockey and lacrosse.

Joseph Siprut, the lead plaintiffs’ attorney who spearheaded talks with the NCAA, said the sometimes-tough negotiations ended with a deal that will make college athletics safer.

“I wouldn’t say these changes solve the safety problems, but they do reduce the risks,” the Chicago attorney said Tuesday. “It’s changed college sports forever.”

The NCAA hailed the settlement.

“This agreement’s proactive measures will ensure student-athletes have access to high quality medical care by physicians with experience in the diagnosis, treatment and management of concussions,” NCAA chief medical officer Brian Hainline said in a statement.

Siprut added that stricter oversight and return-to-play rules should help ensure the viability of football by allaying the fears of parents who are currently inclined to not let their kids play.

“Changes were necessary to preserve the talent well of kids that feeds the game of football,” he said. “Absent these kinds of changes, the sport will die.”

There is no cutoff date for when athletes must have played a designated sport at one of the more than 1,000 NCAA member schools to qualify for the medical exams. That means all athletes currently playing and those who participated decades ago could undergo the tests and potentially follow up with damage claims.

To keep the NCAA from having to hold unwieldy talks with multiple plaintiffs, 10 lawsuits filed from Georgia and South Carolina to Minnesota and Missouri were consolidated into the one case in Chicago, where the first lawsuit was filed in 2011. Combined, the suits identified several dozen athletes by name as having suffered brain trauma.

The lead plaintiff is Adrian Arrington, a former safety at Eastern Illinois. He said he endured five concussions while playing, some so severe he has said he couldn’t recognize his parents afterward. Subsequent headaches, memory loss, seizures and depression made it difficult to work or even care for his children, filings said.

Another named plaintiff is former Central Arkansas wide receiver Derek K. Owens. After several concussions, he said he found he could no longer retain what he had just studied. His symptoms became so severe he dropped out of school in 2011, telling his mother: “I feel like a 22-year-old with Alzheimer’s.”

Among other settlement terms, all athletes will take baseline neurological tests to start each year to help doctors determine the severity of any concussion during the season; concussion education will be mandated for coaches and athletes; and a new, independent Medical Science Committee will oversee the medical testing.

The NCAA admits no wrongdoing in the settlement and has denied understating the dangers of concussions. As proof it has tried to mitigate the risks, it has cited recent changes in equipment, medical practices and playing rules, including ones prohibiting football players from targeting an opponent’s head or neck.

The NCAA also announced in May a three-year, $30 million concussion study co-funded by the U.S. Defense Department. Plans call for initial data collection on about 7,200 athletes from 12 colleges, increasing to 37,000 athletes at 30 sites, with the aim of better understanding concussions and developing better prevention methods.

The settlement is still subject to approval by U.S. District Judge John Lee, in a process that could take months. He must grant preliminary approval and then, after affected athletes weigh in, give a final OK.

Plaintiffs’ filings say the number of athletes who may require testing to learn if they suffered long-term damage runs into the tens of thousands. They cite NCAA figures that from 2004 to 2009 alone, 29,225 NCAA athletes suffered concussions — about 16,000 in football, 5,751 in women’s soccer and 3,374 in men’s soccer.

Internal emails unsealed in the lawsuit illustrate how pressure mounted on the NCAA over the issue.

In a Feb. 23, 2010, email, the NCAA’s director of government relations, Abe Frank, wondered about debates elsewhere, including in Congress, about recommended new safeguards for young children playing contact sports.

“Do you think this renewed emphasis on youth sports will increase the pressure on the NCAA to do more at the college level?” he asks in the email sent to the NCAA’s then-director of health and safety.

David Klossner responded bluntly a few hours later. “Well since we don’t currently require anything all steps are higher than ours,” he wrote.

Later that year, the NCAA did establish a new head-injury policy that requires each school to have a concussion management plan on hand and it states that athletes should be kept from play for at least a day after a concussion; it also requires players to sign a statement “accepting responsibility for reporting their injuries.”

But plaintiffs argued schools put too much of the onus on athletes with little understanding of concussions to self-report injuries. And they blamed a tendency of some teams to hurry concussed players back into games according to patchy, uneven plans and the NCAA’s lax enforcement of the concussions policy.

In a 2012 deposition, Klossner conceded the NCAA provides virtually no oversight of concussion management plans and that schools aren’t required to submit them to the NCAA. Asked if any schools had been disciplined for having subpar plans, Klossner said, “Not to my knowledge.”

Prior to the settlement, plaintiffs were scathing about how the NCAA handled the head injury issue for decades.

Instead of adopting stricter protections for athletes, the lawsuit said the NCAA chose “to sacrifice them on an altar of money and profits,” an approach that occurred even though the NCAA had known for at least a decade “of the correlation between concussions and depression, dementia and early onset Alzheimer’s disease.”

The plaintiffs cited a 2010 internal NCAA survey that found almost half of college trainers put athletes with signs of a concussion back into the same game.