Well, I tried some of the gentle exercises and took a couple of aspirin. I looked up some information on acupressure online.....I actually had some experience with this back in the eighties, when I was working out a lot in karate class, and one of the black belts showed me how to use it for a headache. Anyway, the acupressure seemed to have an effect. When I maintained the pressure for a couple of minutes, I could feel kind of a fuzzy tingling in the area where I'm having the trouble. I did it right before I went to bed, and while I was lying in bed, I could bend my knee quite a ways and thought it was improving, but when I tried standing on it and squatting down -- no go. I don't know what the difference is, but squatting down it won't bend.

I think I can feel a slight amount of improved flexibility today, so maybe one or more of the "treatments" is working. I'll keep you posted!

ETA: Oh yeah, I have to tell you, Oscar Wilde, this V
.... stay within hopping / crawling distance from your house.
cracked me up! It lightened me up, when I was feeling too worried. Thank you. And if I go for a walk, I will keep that in mind.