I caught him (there was a lot of protesting), locked us in a room and forced-fed him some small balls of mince. At first he accepted them and I though he'd settle down, but then he remembered that he was a Wild Bird, and this handling was Just Not On. Instead of letting me poke the food into his throat, he pecked and snapped at my fingers and the meat, and flicked lumps of it all over the place. He escaped my grip while I was trying to control him, but instead of flapping to escape he rolled onto his back and lashed out with his feet. Every time I moved he'd roll into a position that put his feet between me and his head. I walked a full circuit around the bed and watched the maniac bird roll around on the sheet.
I flicked a couple of meal worms onto the sheet, but the bird ignored them and continued to roll on it's back, lashing out and snapping at every opportunity until ooh crawley food near me! He was very surprised to discover he'd been caught while eating the meal worms. I got a few more meat lumps into his crop, then put him and another load of worms back into the cage.
I really hope his wing gets better.