Biu sao is a forwardly oriented movement, regularly used under the other arm as an emergency attack. It points towards the target one wants to...
encyclopaedie
The gaan sao is a hand move that reminds of a plough. It moves downwards following the orientation line.
As kwan sao, we describe a move composed of a tan sao and a deep bong sao. It is a defensive as well as an offensive move.