I've got weak knees too, so am hoping to learn more from anyone. I got mine from skiing w/out building up the muscles first. I originally planned on only going skiing once a week through a college program, then started going several times a week, then went crazy w/ how much I loved it & went every single day I could. I had a blast & got carried away. I ended up having an arthroscopy (sp?)on each knee because the cartilage became inflamed & needed to be scraped. The right knee healed very well, the left did not. I originally only had problems w/ my left knee, now have problems w/ both knees. They hurt very easily from walkng or exercising.
I'll keep checking back to see if anyone ever writes more here...
olga p