The trapped nerve in my neck, which has stopped me from cycling, walking, or doing owt much at all for the last two years, seems to have resolved itself. Dunno why I got it in the first place, nor why it went away - doing my usual yoga class before christmas, Something Happened at one point to make it better down my left hand side (where the pain was all along), but suddenly worse down the right (where it wasn't).
Over a couple of weeks, the worse bit gradually improved and went away completely, and the better bit stayed better. A decent gym session last Friday, a 3 hour ride yesterday and a 3 hour walk on the fells today and all seems to be well. I think I'm better
Now, just the small matter of 2 years-worth of lost fitness to catch up on.