Flare up of pain

[spiderowl]

I play a musical instrument and often spend hours practising. Occasionally, I have aches and pains, but I stop playing for a few hours and they fade. Just recently, I've had a lot of pain in one arm/hand/shoulder/back just below where shoulder blades meet spine mainly, but now also in other hand/arm/shoulder/back - you name it.

 

I spoke to Doc and she says RSI and to rest affected parts. Apparently, it's not likely to be a trapped nerve because it wouldn't cause pain where I've described on back. She didn't prescribe anything. I'm following instructions (not got much choice) but this doesn't sound right to me. If it's RSI, why am I getting pain in other places? I'm not over-compensating with the other arm, for example. Why get back pain between the shoulders and much lower in lumbar region? Why do I feel achey all over all of a sudden? I feel it's more likely some inflammatory process that has flared up.

 

I wonder if anyone has experienced anything like this or has any thoughts on causes/cures? I am desperate to get rid of this problem as it affects both work and my music. It's a serious matter to me.