WASHINGTON — President Barack Obama called Thursday for more robust research into youth concussions, saying that deep uncertainty remains over both the scope of the troubling issue and the long-term effects on young people.“We want our kids participating in sports,” Obama said as he opened a daylong concussion summit at the White House. “As parents, though, we want to keep them safe, and that means we have to have better information.” The summit signaled an effort by Obama to use the power of the presidency to elevate a national conversation over youth concussions. The White House brought together representatives of professional sports leagues, coaches, parents, young athletes, medical professionals and others for the event. Obama, an avid sports fan and father of two daughters involved in athletics, highlighted millions of dollars in pledges and other support from the National Football League, the National Institutes of Health and others to conduct research that could begin to provide answers and improve safety. Among the financial commitments is a $30 million joint research effort by the NCAA and the Defense Department and an NFL commitment of $25 million over three years to promote youth sports safety. The president said additional research needs to be combined with a broader recognition of the need to take the matter seriously. “We have to change a culture that says, ‘Suck it up,’ ” he said. Obama has waded into the concussion debate before, saying that if he had sons, he would “have to think long and hard” about whether to let them play football. Obama tried to broaden the discussion over head injuries, saying that young people who play soccer, lacrosse, hockey and other sports are also at risk. A concussion is a type of traumatic brain injury that can be caused by a blow to the head or a blow to the body powerful enough to jostle the brain inside the skull. Nearly 250,000 kids and young adults visit emergency rooms each year with brain injuries caused by sports or other recreational activity, the White House said. The NFL recently agreed to pay $765 million to settle concussion claims by thousands of former players whose complaints range from headaches to Alzheimer’s disease. That settlement is awaiting a judge’s approval. A group of former professional hockey players has filed a class-action lawsuit against the National Hockey League for head injuries sustained on the ice. The White House summit also looked at concussions and other brain injuries suffered by service members. Gen. Ray Odierno, the Army chief of staff, was participating. An afternoon sports clinic on the South Lawn with Obama and kids from local YMCA programs was canceled because of rain.