The prank that went viral on the TikTok app is causing children severe injuries across the United States and the world.The skull-breaker challenge involves two people fooling a third person into jumping into the air, kicking their feet out from under them."I couldn't get up because I couldn't feel my hands," said Kathleen. "I couldn't feel my legs, my feet, nothing. I was numb."Thirteen-year-old Kathleen DeJesus was a target in the challenge. She was rushed from Lawrence Massachusetts Middle School to the hospital, where she spent two days for a severe concussion."I was screaming that I needed an ambulance," said Kathleen. "I was thinking like 'Oh my God I'm going to lose my life over this game.' I should have never done it."In Portland, Oregon another 14-year-old student fell victim."These seniors asked me if I would jump for their TikTok video," Olivia Ross said.She said she hit her head on the ground really hard."I remember like blacking out for a second and I started to get like an instant pressure headache," Ross said.The potential long-lasting injuries now have medical professionals posting their own videos warning people, especially young ones."The biggest concern we have, and we know this through research, is we're having a real big problem when it comes to our adolescence and our teenagers with these different challenges," said Dr. Taz.This isn't the first challenge on TikTok to cause harm. The outlet or penny challenge has also sparked damage and even fires.The app told ABC News that user safety is a top priority and they "do not allow content that encourages or replicates dangerous challenges that might lead to injury."