Phoenix is about 8-10 years old. Female. One of her back legs is 3 times the size it should be. Its swollen and theirs no movement. The other leg looks smaller then usual with little movement. The leg that has movement is always tucked underneath her. I haven't seen her move her tail but I can see that the muscles in her tail near her body (not the tip) can move. She's having a hard time moving around.
I forgot to change the UVB bulb but just did last week. her eating habits seem to be ok, maybe a little low but she's still eating. She's alert but not moving that much.

Does anybody have an idea of what can be done to get her back up to par?