By Mollie Bloudoff-Indelicato NEW YORK (Reuters Health) – Twenty-five percent of adolescents in the U.S. have ridden an all-terrain vehicle (ATV) but less than half of them regularly wear helmets and a quarter never do, according to Centers for Disease Control and Prevention researchers. Helmet non-use among youth is a particular concern because these riders have a greater likelihood of crashing than adults, and their likelihood of dying or sustaining a serious TBI is much higher,” said Bethany West, an epidemiologist at the CDC in Atlanta and coauthor of the study. U.S. Olympic Swimmer Amy Van Dyken, 41, was left paralyzed after severing her spine in an ATV accident last month (see Reuters story of June 18, 2014, here: http://reut.rs/V9fl3d). In 2011, an estimated 29,000 children were hospitalized because of ATV-related injuries, according to a U.S. Consumer Product Safety Commission report.