As I understand it(correct me if I'm wrong), Kung Lao is the decendant of Liu Kang in Mortal Kombat.
In grab form, a Kung Lao is simply a Liu Kang in which the skiier fails to kick up and out(true Liu Kang) creating a perpendicular ski position(when looking from the side), instead he/she kicks down in a parallel ski fashion. This far easier in all tricks and is responsible for the death of the true Kang.
(yes they are just 2 different styles of the same grab but so are mutes and high mutes)