A high school student has helped solve a long-standing mystery about head injuries. During falls or traffic accidents, the brain is usually injured in two places - one where the skull strikes the external surface (coup), and another diametrically opposite to it (contrecoup). The most popular theory to explain this is that the brain first collides against the skull near the point of impact, and then rebounds, hitting the skull at the back. But this does not explain why the contrecoup injury is often more pronounced than the coup. Now Laura Drew, a student at Oakwood High School in Dayton, Ohio, has shown why, with help from her father William Drew, chief of neurology at the Wright Patterson Air Force Base in Dayton. "It was my idea, but it was my daughter who got around to it," says Drew http://www.newscientist.com/news/news.jsp?id=ns99993578