Re: Suwari waza
For the suwari waza posture, in order to be stable you need to stick your stomach out. This is so you wont easily be pushed or pulled. Its a much more stable position. Try it out with a friend experimenting how the belly affects stability and groundedness, sticking in or sticking out. We also have this "keiza" position (toes) which is a ready/fighting position rather than "seiza".