I've heard reverse breathing explained as: When breathing in, contract the abdomen. When breathing out, extend the abdomen. My questions are based on this understanding - but if this is wrong, or incomplete - please help me see what I am missing.
Is the abdominal expansion/contraction strictly physical? or is it more a matter of intention/attitude? Or some point along the spectrum? If it's a spectrum from strictly physical to strictly awareness/visualization, are there specific instructions for how to work with that spectrum?
For those familiar with Bill Gleason's approach - When combining breath with different postures as in the video below, Does the in-breath coincide with expansion of the chest cavity (while at the same time contracting the lower abdominal cavity)? Does breathing out coincide with expansion of the lower abdominal cavity? Should you have the same sense of "pushing out" through your arms and legs? If so, should the attention/intention/awareness given to the limbs predominate over the attention in the abdomen, or do they balance, or does the abdominal awareness predominate?
PS: "Intention", "Attention", "Awareness", "Visualization" - different words, different nuances, none of them quite capture what I mean, but all of them are kinda close...so I'm using I'm using them in conjunction.