Hi, I'm starting to get some worryingly RSI-esque pains in my fretting hand. Just on my left index finger knuckle (near the base), it starts to feel a bit sorta weird/tight, and hurts a little bit once in a while. Anyway - warming up and warming down. How would I go about doing it? Just playing something I can play easily slowly then speeding up gradually? Opposite for warming down? Thanks for any help! Mark.