[LisaS]

you're not confusing abduction/adduction of the wrist with pronation/supination are you?
imagine you are standing with arms down & palms facing backward. now rotate your forearm so your palm faces forward. That is supination. Pronation is putting it back.
Now imagine you are standing with your palm facing foward. cock your wrist so your pinky hits your thigh - that is adduction (towards the midline). Abduction is the movement in the opposite way.

I say that only because I'm having trouble picturing what you describe as really abducting or adducting. Going from neutral to palm down - as a punch - would be pronation. It could just be how I am picturing what you are saying.

AFAIK, no one trains abduction/adduction at the wrist but in how you hold dbs as Cloud9 said, your muscles act to resist being pulled in one or the other direction.