I haven't hit my arm once in probably 1,000 shots because I keep my bows at my correct draw length that keeps a slight bend in the elbow at my anchor point. That is the key .
my zmax is a short brace height bow and will just tick my wrist when i do everything right. as far as hitting my forearm, i haven't in a looooong time.
The fellow at the Archery Den showed me that I needed to hold the bow as if I was saying "Stop" with my hand instead of holding it like a hammer. Once i did this, problem solved.
