I first heard the term kua 胯 explained by Kumar Franzis in the early 1990's. He said something to the effect of, it is the functional space in and around the hip socket that continues up into the torso to just below the ribs.
Chen Zhonghua has a detailed explanation of the kua here. One thing I like about it is that he explains that the definition of what the kua is, will keep changing as your skill and understanding improve. The implication is that we are making a categorical error if we are satisfied with a definition of the kua as either anatomy or physiology.
Sam Masich also has a detailed explanation of the kua, it focuses on understanding the ways we misunderstand culture and language.
Here is my take on it.
The kua is really a list of different exercises and types of awareness. But I would caution the reader, this isn't the sort of list that one can go straight down from one thing to the next. Each of these exercises is a link in a much larger chain of exercises, ideas, concepts, and forms of awareness. I have collected here all the ideas about the kua in one place so that we might have a global or comprehensive discussion about the larger subject.
First off, there are a whole bunch of mobility exercises that need to be learned. The hip region needs to be differentiated from the legs and the torso through various types of folding and spiraling. There are probably ten essential exercises here, which can be expressed with infinite variety since the kua is involved with all movement.
These exercises are important for two primary reasons. First, the differentiation of the kua allows the student to make small physical adjustments that dramatically improve ones position relative to a threat or an opponent. That has an enormous effect on the range of physical strategies one can employ. Second, without the differentiation of the kua the student has movement vulnerabilities that manifest because certain weaker parts of the body are taking strain (like knees or lower back). At the same time stronger parts of the body move in blocks, the intrinsic power of which can not be accessed without differentiation.
After mobility and differentiation are established. The next stage would be transferring force through the kua, from the legs to the torso, and from the torso to the legs.
That can be followed by generating force from the kua. I count seven ways to do this. They are all fairly simple, but they need to be taught because they tend to be counter intuitive.
Next is liquid movement. There are two parts to it. The first is practicing moving fluid from one part of the body to another until it is easy to generate whole body liquid movement. The second is working with a partner to test ones ability to stay liquid under all sorts of pressure. This is actually true for every part of the body, not just the kua, but it is essential for discovering the higher order functioning of the kua.
The next concept on our list is very important to martial artists but it is better known by its theatrical name, "monkey doesn't want to go to school." It is a way of sinking in response to another person pulling on ones arms, such that, one cannot be pulled forward off of ones feet or base. It does not involve leaning backwards. It is also characterized by complete relaxation of the legs, there is no tightening of the thighs nor of the feet muscles. It is most certainly not a form of "rooting." This skill is often kept secret by martial arts teachers, and children often do it naturally without being taught.
Building on "monkey doesn't want to go to school," we finally come to opening the kua. I charge $10,000 dollars for this teaching. But I guarantee you will learn it in ten years or you get your money back.
I'm tempted to say that the ability to open ones kua is rare. But it isn't that rare, lots of ballet dancers do it. And there are all kinds of situations where people open their kua without naming it, perhaps you do this when you stick your toe into the river to test the temperature before making a full plunge. But what is rare is the ability to keep the kua opening in response to complex forces.
To accomplish this last step requires a cascade of discrete skills, executed in the right order, and practiced, not just until they are natural and spontaneous, but to the point where they re-form and re-shape ones body.
This is unequivocally a daoist art form, and requires direct daoist transmission. Scholars are still uncomfortable with the idea that there is a form of authentic daoism that doesn't have a textual lineage, they generally refer to people like me as a "practitioner." That's okay, but there is a categorical problem with this term; namely that people who receive daoist transmissions prioritize view and fruition over methods. Methods tend to be disheveled, flexible, expressive and spontaneous. In that sense, I'm not a "practitioner," it is a mistake to point to what I practice. I'm actually a daoist because of my view of the human relationship to nature, and the experience and expression of the fruition of that view.
Anyway back to methods, sort of. The non-conceptual experience of sitting and forgetting (zuowang 坐忘), by definition can not be expressed in words. This same view is foundational for practicing zhanzhuang 站桩 (standing still), daoyin 導引 (pulling and guiding), jindan 金丹 (golden elixir). If I had to name it, I'd say it is an experience of limitless space, a stage if you will, wuwei 無為, an agenda-less openness of not knowing. Once that is irreversibly established, then these methods can dance around on the stage as: emptiness, stillness, movement, bubbling, flowing, fire and water, mercury and gold, or the magical and the mundane.
Opening the kua is a form of emptiness. This type of emptiness arises spontaneously when we drop all intention within the body--also giving rise to a visualized qi body out in the space around us. But that isn't enough. Because simply having qi and emptiness is not stable under the pressure of complex movement and outside forces. This 'event' must take place in a larger experience of limitless space. The space can then be moved using the imagination. But that only works if the qi body is simultaneously felt and imagined.
So the whole thing is actually pretty easy. Like I said, for $10,000... guaranteed. Opening the kua can also be awesome for ones health, but since that idea is associated with Tai Chi and is so cliché and problematic, I will deal with it in a future post.
Warning: The information in this post has previously been top secret, anyone attempting to practice it without the proper initiations will surely shorten their lives.