Xue Sheng
All weight is underside
I found this rather interesting
International Wushu Federation
Competition Rules
Taolu Competition Rules
Sanshou Competition Rules
International Wushu Federation
Competition Rules
Taolu Competition Rules
Sanshou Competition Rules
CHAPTER 4
FIGHTING METHODS, SCORING CRITERIA AND PENALTIES
Article 17 Fighting Methods
All attacking and defending techniques of sanshou may be used in fighting.
Article 18 - Prohibited Methods
20.1 Attacking with the head, the elbow, or the knee, or by twisting the opponent's joints.
20.2 Forcing the opponent to fall head over heels, or intentionally smashing or pressing him down.
20.3 Hitting the opponent’s head by any means when he is already down.
Article 19 Prohibited Areas
The back of head, the neck and the crotch.
Article 20 Scoring Areas
The head, the trunk and the thighs.