Keep in mind you don't have to swing the controller as if you actually did have a tennis racket/ sword/ whatever in your hand. A quick flick of the wrist does the same as a wild swing. The strap is adjustable to fit snugly on the wrist so as long as you can keep a good grip it shouldn't snap off at all. If smething like you decribed doing does happen it's their own bloody fault for not doing thing as they were told.