Never say never...just because you don't train it or don't see it...doesn't mean it won't work. If you apply a proper hold and are sensitive and can feel where the person is going in their resistance, then I think you can restrain someone in a standing position and if you so desire, break their arm from that position. Several things come up though: putting them to the ground is a much better place to control them. When one resists it is easier to apply a hold than if they are loose and flow with the movement. In a full out fightin situation, striking is much preferable from my perspective. IN a sudden self-defense situation, using restraints can be a good option and surprise followed by breaking limbs can be implemented...a shoulder break, an elbow break, etc.

That said, why do you want to break someone's arm? Is it not enough to restrain them? I suppose the situation would dictate the course of action but I think it is possible to break someone's limbs standing up.