As you probably could hear in chopscerzo2mess, the larger muscles of my trunk have become uncoordinated. All those missed bass notes show that my upper back and pectoral muscles are tense and out of shape, due to the endless weeks in bed. Building strength and flexibility is the first logical step in rebuilding my technical skills.
I tried some light upper-body weight training today and wow, I could barley curl 10lbs! My muscles are weak! I'll be doing a total body routine (including all muscle groups, save the lower back) every other day. For aerobic training, I'll continue to walk about 30km a week. I also have started a light stretching routine; I'm very inflexible; this has to be part of the problem. Even if I don't succeed in my mission to re-master the piano, I'll look good in board shorts!
As for my fingers, I thought a good place to start would be Hanon. It's simple (boring) but easy on my relatively untrained hands. I'll play the first 10 exercises twice in a row every other morning. I think scale and arpeggio practice would be too strenuous for now.
I'll try this for a few weeks before I (physically) dive into that repertoire.