In reply to Garethza:
Good thread, I've thought about this myself and I'm sure certain playing styles stress the same muscles/tendons as hangboarding. I think it all depends on the string gauge and style, intensity, attack, etc... How/what strings do you play?
I cycle between .13s and .12s and play SRV style blues, so lots of big bends, and a constant, heavy attack with the R hand. Even when playing a single note I rake across the other muted strings to "rough it up a bit". Sometimes I play every day, other times I don't play for a week. I think I'm the perfect candidate for carpel tunnel syndrome.
I've been playing like that for years but only hang boarding for 11 months. In that time I've had my first sight of carpel tunnel syndrome and elbow problems but which have gone away quickly with a drop in intensity (on the board) and good stretching - of the extensors in particular.
Does that relate to your experience? I hope you don't have to give either up!