From the description of the youtube video:
Wujifa practice aims to develop full body usage, effectiveness, movement, and strength. Visit http://wujifaliangong.blogspot.com/. In Wujifa the "Side to Side" practice works toward development of the inguinal crease or Kua. In this video people at varies levels of skill are practicing the first set of the Wujifa inguinal crease development program. As in many internal martial arts, qigongs, and yoga, this practice as well as other Wujifa practices are about development and gaining greater understand and depth through doing, training, and mental development.
One of the corrections I received at the Chen Zhonghua workshop was to not “fold” the kua when doing the positive circles. Both kua must remain active. From what I am seeing in the video above, the while there is an open/close in the kua, the closing kua is still “active”. This is something I am working on in my own training.
Props to Rick for putting up this video. I especially like the descriptions and pointers in between the video segments.