First of all, thank you Tim for all of your books, especially the recent translation of Sun Lu Tang's Tai Ji book.
In the discussion of Lazy Tying Coat (section two), the translation says that the kua should have, "an energy that feels as if it is pulling backward." The footnote comments that this will stop, "the pelvis from curling under at the rear."
Is this the same as keeping the kua open? Is the pelvis curling under the same thing as the tailbone moving forward and up?
Thanks so much for any replies.
The alignments in Sun style are based on opposition of forces to keep the body centered and stable.
In order to keep the pelvis aligned, the lower back is relaxed, allowing the tailbone to drop a little (moving forward and upward). At the same time, to keep the hips from curling under too far ("tucking the rear"), there is a simultaneous pull in at the front of the hips (kua).
Thanks much for your prompt reply. You have cleared up my confusion.
In Bagua, Xing I, and Tai Chi, is one of the principles to have you "hips tuck"? I always make sure I keep that during practice, And I would like to know how much is too far "tucking the rear".
We try to keep the alignment of the spine as relaxed and natural as possible. If you are using force to pull your hips up to the front, it is too far (just as if you are using force to arch your back, it is too far in the other direction).
Relaxing the lower back allows the tailbone to drop a little, but there should still be a curve in the lower back. Nature put it there for a reason.