Go on YouTube. There is just about every type of exercise. Just move those joints. Every movement will help move to the next. Keeping them. Still makes them stiff. Movement no matter how little , leads to the next. Until it gets easier. ~😁
One of my favorite workouts when I lived near a YMCA was water aerobics. Most YMCAs offer them, so maybe that would be an optio, especially during intense pain and flare-ups.
Another thing I like to do to get my heart rate up when my knees are killing me is to put on music (or a Richard Simmons DVD) and grab a chair from the dining table and just use my upper body. The key is to just move, so it doesn't matter what it looks like, just smile and move to get that heart rate up. 🙂
On the days that I can barely move, I simply sit in as hot of a shower that I can stand. This creates a sauna effect (if you have access to a sauna, use it as long as is safe for your body). This will bring your heart rate up mildly, even on those days that movement is near impossible.
Thankfully, I do still have good days and although I've had to give up biking and and high-impact sports, I take those good days to go out and walk my dog in our local park. It's an easy walk and we can make quite a few rounds, if I bring enough water. 🙂
I hope some of these suggestions help and maybe spark some ideas that you can use in your own situations. I think the most helpful thing I've had to learn is to just keep going, even if my body has to slow to only an inch a day.
However, I think that the best exercises for those with arthritis and general pain are exercises in a pool, preferably a therapy pool that is kept over 89 degrees.
To be able to use a therapy pool one usually needs a ‘prescription’ from a doctor, and unless you know what you are doing, I highly recommend (plus it is probably mandatory) that everyone start with several sessions in the pool with a physical therapist who can evaluate you situation and assess your needs, and then create a custom routine: a specific set of exercises that you would do every day that you are at the pool. For an aerobic workout, swim laps before and after your exercise routine.
Hope this helps.