大腿,旋转

In the positive and negative circles, the thigh rotates outward in the opposite direction from the turning of the waist.  This, along with tucking in the tailbone and pushing out the lower back, helps to keep the front flat so as to attain “no indentation and no protrusion”.  So if the front is flat then the kua can’t fold (indentation) and the butt can’t stick out (protrusion) so the kua must only move downwards as the thigh rotates outwards for this move.

Kham Serk