Dear Scott Campbell,
Please, sir, please get yourself in some life-drawing classes. Not just freeform sessions, an actual class where you will learn about line of action, anatomy, and realistic movement and posing. I know this helped me a lot, and I need to schedule my time to life draw again. Barring that, please consult books on anatomy for artists, I’m sure you have some, you must, but please.
Also, it would be helpful for you to take some archery classes. They say draw what you know, and if you don’t know it, find reference. Not just reference as to what a bow looks like, but how you actually shoot one.