hi, rivergrl. welcome to te! I have had arthritis in just about every joint (including knees) since I was 10y/o (I'm 40 now). From what my "bone md" has told me: the key is building the muscles around the joint and keeping myself flexible.

My arthritis will worsen but the muscle groups that I've built up, along w/the flexibility, has helped prevent the arthritis from limiting my motion.

I would encourage you to also check w/an MD (maybe your Mom's?) to find out if there is anything you can do to prevent and/or minimize the effect of the arthritis.

I only have my experience to share: cycling has been great for my arthritis: keeps me limber, moves my joints around, but isn't as painful as running.