This term is also applied to
snowboarding, and occasionally
surfing. Theories are that this has something to do with the relative strengths of the legs, or the overall
footedness of the
rider, i.e. right-footed or left-footed. There was originally some attempt to connect riding style with
handedness (right or left), however handedness has been demonstrated to be considerably independent of footedness.
I happen to ride regular-footed, so this node gets a longer write-up than the other one.