Here is a handlebar suggestion for mountain bikes that many people don't think about anymore because it is out of vogue. When I started riding mountain bikes, or shortly thereafter, bar ends were in vogue. I can't ride a mountain bike without them now. They allow you to rest your hands a bit - I don't have carpal tunnel, but do have problems with insufficient tendon support at my wrist, so having this different position is key for me. They do not have to be long bar ends, they can be just about 4 or so inches long and they do the trick. They give you a different position for when you are climbing, etc. You do have to get out of them to brake.

Another suggestion with a mountain bike is to try different grips that will help your hands. Some grips are smoother, some with more friction (rougher); some larger in diameter - so give them a try to see if some other grips might help you.

spoke