The laan sao will be described as locking arm. It is used to free some space from the opponent in front of the body, to build up space in which...
encyclopaedie
The scissors gaan sao is to be considered equally as defensive or offensive move. It protects the whole upper body from waist to head.
What we describe as jum sao is the sinking elbow. This minimal move protects the under part of the upper body like belly and liver.
The gaan sao is a hand move that reminds of a plough. It moves downwards following the orientation line.