It was time to study the wings. The more I know the better I can draw them.
I've had some confusion on the bone and muscle structure of the wings for some time now. As you can see below, the arms do not attach to the outer lining of the wings when it's outstretched. Instead, the humerus and radius/ulna are still slightly bent and there is a flap/ligament that connects from the shoulders to the "wrist" of the wing.