Anyway, today's fettle involved replacing a broken spoke in barakta's motor wheel, that I'd discovered while playing musical brakes[1] last week. Astoundingly, it's a lot easier to obtain spokes in silly short sizes than it was a few years ago, which is just as well, as the one in question was a whole 96mm.
Alas, this involved doing battle with a Marathon Plus on a 20" wheel, which eventually succumbed to a combination of cable ties, VAR tyre lever and harsh language.
Having sorted that out, I fitted the non-motor wheel to the trike and installed it on the turbo trainer. The physioterrorists having approved light pedalling with no resistance. This should hopefully prevent excessive bouts of OwMeKnee when she's able to walk again.
[1] One of the BB7s from the dead Streetmachine replacing a knackered Tektro thing that was serving as a parking brake on her trike. The main idea was the ability to adjust the stationary pad without removing the wheel (the motor blocks direct access), but this also appears to have provided a major boost in braking performance. Skidz, for the doing of.