does the shoulder whirl work with a vertical fist? I dont think there is any way to adjust it to work in that manner, but at the same time i am not a boxer by trade. Have been trying to incorporate some boxing techniques into what i do though for more power, since karate just doesnt cut it sometimes.

Shoulder whirl?

What, pray tell is that?

Never heard that term before, but he may be referring to a circular wind up at the shoulder joint for punching power. I was recently shown something like that. I don't know enough about it to say with certainty if it can be used for vertical punches. The elbow seems to pull away from the body somewhat from what I have seen.

The "whipping" action it imparts to the strike does seem like it could add some power. If we are talking about the same thing.

I think you're onto it. This seems to be the same punching technique Chuck Lidell uses, by leading inward and pushing his shoulder before his fist, he creates that "whipping" effect you spoke of.

I don't see why one couldn't use a verticle fist in this manner if the blow is not and overhand/ downward hook. If it was delivered to the body, a vert. fist could be used.