So I was at a dressage clinic the other day, and one of the horses was acting up a lot. She was tossing her head and hopping up and down like she was going to rear. She just wouldn't listen to the rider, and the person next to me said, "that horse needs to be disciplined." I haven't had to encounter or ride a horse that acted up like that before, so I was wondering how you would discipline the horse in such a scenario. I noticed that the rider jerked on the reins, but that was pretty much it. Unless she used some leg, which I didn't notice.