Aedh’s been telling me for years to bend at the hips, that’s one reason I do the wall squat–it requires this to be successful. For the past year or so he has been talking about as the hips go back that you get a rounded space.
I think I’ve got it figured out what he is talking about, and I don’t see it as a round space. I see it as a sphere, round in all directions. And the point of achieving that sphere is that when one pushes on a sphere it just moves. If you get on top of it, or it somehow ends up under you, it is a particularly unstable situation and you are liable to end up sailing onto the ground or against whatever fixed object is in the way.
There is a chance I can practice this in my standing posture (tree) and wall squat. Been looking for a meaningful push hands exercise I can do by myself for 38 years! I think/hope I’ve got it!