IF you are using bone structure and NOT arm muscle, there is no way the hand will go behind the head. Your hand will end up on your face somewhere NEAR a finger in the corner of the mouth/tooth.
Arne
This is exactly correct, but I would only elaborate...
If you think about it, you really want to be only pushing the bow by holding out the bow arm straight ahead, parallel to the shoulders, because it is inherently strong there, and the effort required by the shoulders to stabilize it is minimal. I.e., you have the best leverage. You still want to actively push in forward, while still keeping the shoulder down (so that it isn't prone to collapse into your neck), in order to keep the bow arm stable. On the pulling side, you only use enough arm muscle in your forearm to keep the string on your fingers, nothing more. That means a deep hook, string in the finger grooves, fingers pulled as straight and slack as you can without letting go, and no effort felt within your arms and rotator cuff. All of the pull is accomplished by simply rotating the elbow behind you until you have the arrow under your eye, however your personal geometry will allow. This can only go so far. You may still want to 'pull' through the shot, but ergonomically, it is a natural 'stop'. You can pull further, but it requires activating your rotator cuff muscles and/or your biceps or triceps, depending on how you're doing it. Using these muscles not only breaks alignment, but becomes FAR harder, and places a LOT more stress on your joints. I would venture that most injuries related to archery involve poor alignment and shooting form. I've personally had shoulder irritation related to shooting a compound bow with the draw length set far too long, which is pretty much the same thing, and what at least half of compound shooters I see do on a regular basis.