Evidence is growing that playing contact sports can lead to long-term brain injuries

Meeting Nelson Mandela should be a high point in anyone’s life. But Alix Popham, a Welsh former rugby player who once met the legendary president of South Africa before a match, has no memory of the encounter. Later that day during the game, he was struck so hard on the head that he suffered a severe concussion, an injury in which his brain was thrown around inside his skull.