When the N.F.L. agreed in 2012 to donate tens of millions of dollars to concussion research overseen by the National Institutes of Health, it was widely seen as a positive turning point in football’s long history of playing down the long-term effects of brain injuries on players. At the time, the league said that it would have no influence over how the money was used.
But the league and its head, neck and spine committee worked to improperly influence the government research, trying to steer the study toward a doctor with ties to the league, according to a study conducted and released by a congressional committee on Monday.