You can use 16 oz water bottles as weights to do arm exercises. And if lifting 1 pound, empty the bottles to half full. I know that moving when I hurt isn't fun, but moving gently loosens up my joints, so they don't hurt too much.
I might suggest looking into your diet, we often eat food that can cause inflamation which don't help our joints at all. Some foods to avoid or reduce would include red meats, processed meats (deli meats, bacon, hot dogs), chips, cookies, processed grains. look up inflammatory foods for a list. you will also find foods to eat as well. I am realizing that my diet is extremely important and I am trying to improve it.