Recently, the Wujifaliangong blog posted an excellent video and article on the side-to-side exercise. See "Keys for Developing the Inguinal Crease, aka Kua, with Wujifa Side to Side Practice. Of all the videos available, and there aren't a lot, this is the first I've seen that focuses at this level of detail on developing feeling in the kua.
"The process of side to side allows a very specific focus to guide people in making progress towards understanding the inguinal creases which is so very helpful in deeper discoveries of full-body movement and practice."
Watching this video, you might think, "Oh, all they're doing is shifting weight. So what? I can do that." Or, you may think, there's something there, and try to imitate what you see.
After practicing side to side (on and off) over the last few years and seeing new students in class learning this exercise, I offer a couple observations and training tips which are my own and not part of the Wujifa curriculum.
If you've been exposed to any of the Structural Integration bodywork therapies, for example, Rolfing Massage, you know that over time, your body develops certain muscular holding patterns and fascial adhesions which "twist" your structure; defining patterns of movement and certain ranges of motion.
When you first come to the side to side practice, you will "naturally" perform side to side with your own unique structural twist. Part of the beauty of this exercise is that it provides a benchmark against which you can gauge and relax through your particular holding patterns.
Notice in the video how the students demonstrate moving as if sliding on a pole. If no one is watching you (caveat, someone who knows what to look for) to observe if you are keeping your hips level on both the horizontal and vertical plane as you move, and keeping the knees in place, then how do you know if you are doing side to side at this beginning level? How do you work on / relax through your internal structural twist?
When I started practicing side to side at home, in between classes, I used the following to help me notice what my body was doing. And I still go back to these from time to time.
1. Stand facing a wall with your feet a little more than shoulder length apart and your toes an inch or two away from the wall. Now, bend your knees so the knees touch the wall. Glue your knees to those spots. Now shift side to side. (I do this at the kitchen sink with my knees against the cabinet door so I don't look like such a nerd.) This helped me develop a feel for the kua opening and closing. If there is any pain, move the feet closer together and don't bend at the knees so much.
2. Find something, a countertop, the back of a sofa, a table, that is about your butt height when you slightly bend your knees. Lightly back into a tabletop or whatever, and keeping the knees in place from #1, slide back and forth paying attention to maintaining a light contact between your butt and the tabletop, noticing if there are any differences in pressure between your butt and table. Smooth those out to keep the pressure light and constant. This helped me develop a feel for if I was twisting my hips or keeping them level.
Keep in mind though that the aim is to develop a kinesthetic sense or feeling of what is moving under the skin, a.k.a internally. You want to learn to rely on your feeling, not rely on walls and tables. If you are like me, your body will want to twist and turn all over the place. Side to side is a pretty tough exercise to get. I am still learning.
Now even after practicing side to side the last few years, and even after working out some of my courser structural twists, I continue to discover deeper and more subtle holding patterns. What was once called 'subtle' has become obvious and then there is a new level of 'subtle' which in time will become obvious and then there will be a new level of subtle... and... this rabbit hole goes very deep...
I hope this gives you a little insight into how I started. Of course, even following this method is only a rough first step. It is always best to get some "hands on" time with someone who can point out to you what you cannot see and point out those subtle, yet obvious kinesthetic feelings.
And of course, I make the same disclaimer:
"As with any exercise, make sure you are in good enough physical health before attempting this. Ask a doctor if in doubt. "