Proper bow hand set can eliminate or minimize arm slap. The bow hand's lifeline should be centered over the grip of the bow. The bow hand knuckles should be on a 30-45 degree angle (vertical knuckes will hit your arm), and the bow hand should be relaxed. Of course the stance should be slightly open--front foot half step back, feet shoulder width apart, and front foot "opened" about 45 degrees towards the target. This bow hand set is often difficult to get with many recurve handles because of the way they are made. It is much easier to achieve with a narrow gripped compound. Having written all that. To answer your question. I "nick" my bow arm just above the wrist if I shoot a recurve with a brace height less than 7.5 inches. Not so much that I need an armguard but I always wear one when hunting to keep my shirt/coat sleeves at bay.