"These days, not really"That is good, I was a bit isolated for a couple of decades :D
Good point on the legs " Good foundations support strong buildings" especially the quads, someone smarter than I should describe the contraction of aging. Those ankle rotations are a good start. I think you put it better how "The spine is intricate and functions as one unit, to be sure" it took me a long while to learn that. It is the shear and cantilever forces that do one in!!