I've always associated the burning feeling with fibromyalgia. I do get that in shoulders, arms, hips and thighs (more in the large muscles than the actual joints). I don't have tremors - but I'm not sure we're talking about the same thing- I think of tremors as "the shakes". But I do get the muscle twitches and tics - and they are usually some part of a flare. And like Hippi describes - oftentimes my hands just don't work and coordinate well....I get clumsy and can't hold on to things. All of these symptoms usually coincide with increased fatigue and muscle weakness and the need for considerable rest. Sometimes it's hard to pinpoint whether it's the fibro or the AI stuff causing the problems, but the burning muscles were a problem before my ANA switched on. Hope you feel better soon.
Lucy