Chris Nowinski, co-founder of the Sports Legacy Institute, noted that a degenerative brain disease linked with repeated head blows and more often associated with football has recently been found in autopsies of professional soccer players. The new study adds to concerns that have been raised about rough play, he said. The Boston-based institute is a nonprofit education and advocacy group that funds research on preventing and treating concussions and other brain trauma. It also advises the National Football League and groups involving other contact sports including rugby and lacrosse.