They now call it "Quadriplegic rugby," but this rock 'em, sock 'em indoor version of the rough-and-trouble contact sport is actually better served by its original name: murderball. The game is played on a hardwood floor without helmets or pads, and the object is simple: The guy with the ball has to get both wheels of his custom-built, Thunderdome-looking wheelchair over the goal line. The other team tries to stop him by tearing after him and smashing their chairs into anyone that gets in their way. It's like rugby played at a demolition derby, and the fact that it's played by quadriplegic men only makes this thrilling game that much more remarkable. Filmmakers Henry-...