Thanks for you good thoughts, everyone: things improving but my leg still doesn't work properly. It wasn't life-threatening, but I did empty a n2o/o2 (Entonox/'gas and air') cylinder on the way to A & E, and then they had to give me a shedload of morphine.
A quick note for UK members: if you ever need an ambulance, do phone the ambulance service trust HQ afterwards when you're able and ask for your thanks to be passed on to the crew and the dispatcher. They appreciate it.