Freestyle motocross (also known as FMX) is a variation on the sport of motocross in which motorcycle riders attempt to impress judges with jumps and stunts. The backflip was once considered all but impossible, the 'holy grail of FMX'. Freestyle riders began contemplating it after the 1998 film 'Children of a Metal God' showed riders attempting the trick into water. Also it had been done many times on BMX bikes, and FMX riders were using tricks from BMX riders, such as when Travis Pastrana performed an Indian Air, originally from Mat Hoffman, a BMXer.[citation needed] (Source: Wikipedia.org, CC BY-SA)