Never read the book, but psychology changes helped my RSI issues tremendously. > if you are unconsciously worried about something (including worried about your wrists hurting while you type), then this can cause your wrists to hurt while you type. This. If you're scared of RSI and scared of typing, that can itself cause problems.
This is the thing that fixed my problem. After trying so many different "methods" and "tricks", I read about this approach on an HN thread a few years ago. I was skeptical in the beginning but now I'm just dumbfounded how effective it was.