Well ladies, I decided to take your advice and get it checked out. A&E is an hour's drive from us on the other side of the city (that"s what was putting me off getting it looked at, to be honest) but, Maggie, I found we still had a minor injuries clinic attached to our nearest hospital (we thought they'd closed it). Apparently I have severely strained the ligament that runs down the inside of my knee, but there is no major damage. The nurse who looked at the X-rays said "that's a very healthy joint for a lady of your age!" I told her that was reassuring considering everything else is falling to bits at a rate of knots! She did say to keep it mobile, but I won't be going anywhere very far or very fast for a while. Many thanks to you all. ?