We dare you to put your ass in a wheelchair and try any of the tricks that AARON FOTHERINGHAM has invented in the sport he calls "hardcore sitting." "I don't want pity," the 16-year-old says. "What I could really use is some competition." The Las Vegas teen also wants more than the YouTube notoriety he's racked up since nailing his first backflip; he envisions a future X Games category.

Born with spina bifida, which left him paralyzed from his thighs down, Fotheringham first started scaring his mother, Kaylene, at age three by dismounting his bunk bed and landing on his hands. "I called the doctor," she says, "and he said that Aaron's arms are stronger than his legs anyway." By six, Aaron was popping wheelies off curbs; two years later he made his first drop into a skate park.

To perform his signature backflip, Fotheringham uses gravity and his upper body to generate enough speed to get him airborne. Then he pulls back on the frame and looks backwards until the landing comes into view. Fotheringham says his next aim is the "chair-whip." That is, he wants to spin the chair underneath himself for a full rotation and sit back in it before landing.

"If a biker can do it," he says, "so can I."