Everyone loves to say “TaiChi is about balance.”
It’s a plenty-true statement, but when we’re approaching TaiChi Practice through physical exercises (more specifically the moving sequences of Taijiquan) it is more important to remember that our balance comes from TaiChi.
TaiChi is “Great Polarity” and for the postures which express physical balance most blatantly there is one distinct key (which, yes, applies to ALL of the postures/movements to some degree).
Whenever we seek to stand on one leg, the key is to release or sink down.
A skyscraper does not stand up because of the part in the sky!
Even the fourth floor is dependent on something below it.
You’ve got to get to the bottom of things if you intend to stand at all, especially if you intend to stand like a Golden Rooster on one leg!
When your body is allowed to fully sink into one leg, the other can have a feeling of emptiness which allows to “float” or even lift up significantly without disrupting your balance.
On a very simple and practical note, this is so because your center of gravity is lowered and so balance is less difficult.
A more subtle way to think about it is to recognize that the combined action of sinking and raising creates a fairly large combined-range of motion. Rather than raising your knee two-units, you raise the knee one-unit and sink into your standing leg one-unit which still creates the same total movement but splits the effort into halves!
Of course, effective sinking depends on correct posture and alignment which is most rapidly cultivated in your standing meditation (Zhan Zhuang).
Practice makes possible!