“If your feet are on wheels or not touching the ground, you should have a helmet on your head,” says Mary McCarthy, Trauma Injury Prevention and Outreach Coordinator for Westchester Medical Center Health Network (WMCHealth). That includes skiing, sledding, biking and skateboarding. School-age children, especially those over 8, forgo helmets the most — yet they run the highest risk of bike-related brain injury. Correct helmet use is key. “Kids tend to tip them backward, so they’re more comfortable,” McCarthy says. “But that doesn’t given the protective buffer to the brain.” Proper fit means the helmet sits flat on the head, with one to two fingers able to fit above the eyebrows and between harness strap and chin. McCarthy gives children an egg to demonstrate how tightly the brain (yolk) fits inside the skull (shell). When an injured brain swells and bleeds, it has no room to expand, causing damage that can be traumatic.