I finally decided to do something about my back issues and went to see a physical therapist to see how I can improve my posture and strengthen my back to support my crooked spine as it ages. Well, one of the first places she looked was my feet! She noted a fallen arch resulting in over-pronation of one foot. This compounded the effect of a slightly shorter leg which might be part of my back problem. The prescription was "stability running shoes". Didn't even know such a thing existed! So out with the old runners and in with this pair of Asics which have firm arches (different material in the arch section which is more dense) and a heel counter which doesn't give much side-to-side. As it happens these are a great fit for my narrow feet which like a wide toe box, as well.
HERE. Interestingly, after wearing them full time (indoors and out) for a few weeks, I have the impression that my leg/foot is learning to stand with less pronation even after I take them off. Is that possible?