It's also worth mentioning that some of the Qwerty pain can be psychosomatic in origin. Even for me, who hasn't suffered RSI, it was pretty clear that I didn't feel the exertion of Qwerty until I had gotten used to something better (Colemak, in my case.) Once I knew how nice it can feel to type on a keyboard, anything less nice starts mentally hurting – and I'm sure, for some people, also physically.