Avoid playing pieces with overly repetitive patterns too much for too long. Do conditioning exercises religiously, build your strength. It shouldn’t be a problem for a non-professional. You might have fleeting irritations, but I can’t imagine you’d be playing enough to cause something. You should do exercises on the harp for at least 15 minutes a day.
“Avoid playing pieces with overly repetitive patterns too much for too long.”
I want to say a big “YES” to the above! As a harpist who works alot, my experience is that while exercises can be helpful in many ways, the thing that has helped me the most with this problem has been following the advice above.
Another thing that is crucial is to sit high enough at the harp so that you are not reaching up all the time. If you must play music that is demanding and repetitive, at least don’t play it for long without switching to something slow and relaxing. By not over playing demanding music, you can build up stamina faster than if you burn out trying to do too much too fast. The problem may never completely go away, but you can save yourself from carpal tunnel if you are careful.