The "upa" is a movement like a wrestler's bridge where, when flat on your back, you use your feet driving into the ground to thrust your hips upward, during which you roll to one side or the other. This can be used to destabilize your opponent by throwing them off of you to make space for your own movement, to sweep your opponent, and many other uses. "Upa" in this context is meant to evoke, in Portuguese, a wild horse bucking.