NEW YORK, NY (CBS) — As the school year ends and summer kicks off, kids across the country will be jumping on their bikes. But new research shows hundreds of thousands are injured in bike accidents every year. A study, published in the journal Accident Analysis & Prevention, found that more than 2.2 million children ages 5 to 17 were treated in U.S. emergency departments for bicycle-related injuries from 2006 to 2015. That equates to more than 600 cases per day, or 25 every hour. “The most common types of injuries were to the upper extremities,” the senior author of the study, Lara McKenzie, PhD, of the Center for Injury Research and Policy at Nationwide Children’s Hospital , told CBS News. “We saw things like cuts, bruises, fractures, scrapes, and then also traumatic brain injuries.” Nearly half of the injuries in the study involved children 10 to 14 years old and three-quarters of those injured were boys. Injuries occurred most frequently in the street or at home. Traumatic brain injuries accounted for 11 percent of total injuries. “The 10- to 14-year-olds tend not to wear the helmets as much but that’s the group that was injured the most, so we really need to encourage that age group,” McKenzie said. Fewer than half of the states in the U.S. have bike helmet laws, even though studies show wearing a helmet helps protect against serious injuries and keeps kids safer. “Wearing a helmet while riding a bike is the best way to decrease the risk of serious injuries,” McKenzie said in a statement. “We want parents and kids to keep riding their bikes, but it’s important for all riders to wear a helmet. Take your children shopping for bike helmets so you can find ones that fit them and they can choose a style they like. They will be more likely to want to wear it.” Watch below for the bike safety helmet ratings Researchers say kids are also more likely to put on a helmet if they see their parents wearing one, so it’s critical to set a good example. © 2018 CBS Interactive Inc. All Rights Reserved.