if you have the original bars and are leaning forward with all your weight on you hands, you may want to consider risers...these will help you sit in a more upright position

also, you may want to consider a throttle lock, so that you can rest your right hand periodically...

there is also some kind of "paddle" device that fits on your throttle so that you don't have to grip the throttle so tight...

i'm sure someone can be more specific than I....maybe search the threads under throttle and see what you can see....