In a true "fight" you could have bones broken and never even know it until its over. Id never rely on "pain compliance" techniques in self defense situations. Those work in LEO situations where you have to "persuade" "maybe people" into doing what you want. Rarely of practical use in civilian SD..... That's why you don't break bones for pain, you break bones to disable. A guy may not feel a broken knee or broken leg, but he can't walk either. A guy may not feel a broken arm, but he won't be able to grab you with it, regardless.