and here is a good tutorial to make your pivots smoother... http:/community/thread/6536858/pivot-for-dummies-beginners-guide-to-pivot and it looks like you have pivot 2.5, you should download the 3.1 beta version...
I think it'd be better if you made the other limbs move as well, maybe try it on yourself. If you got punched, what limbs do you think would you move by instinct?