I'm not sure to be honest, I think I must just sit deep, keep my leg on and not tense up whilst trying to bring her under control! My girl tends to just do the type of bucking that includes a few back, forth and sideways 'dance moves' too when she's excited but she's not too sharp with it and all but once I've sensed she was about to do it so maybe I've just been lucky to stay on so far - oh except that one time I didn't but I was landing after a jump and was still in a forward seat when the force came from behind - you live and learn!! 