These look pretty Mike! I wanted to do some draw-overs but the photo's being at an angle makes that a bit challenging. It's easier if you take straight on photos of you work.
As feedback, be aware of physics while you draw, especially gravity. The body has to constantly work to stay balanced against gravity. Aim to show the energy and effort that the figure puts into the action you're drawing. This will make it more exciting for both you and the viewer.
Swen has a good point. I'd like to add that if you don't want to be restricted in the future as an artist sometimes switching materials can be beneficial since you have to approach the forms in a different manner. Also I saw sometimes you'd seperate the spine and the leg as two gestures when they go the same way when it would work better with them moving in the idea of one line. Rather than form and shapes first get the relationship of the forms down,draw relying on your natural impulses to guide you rather than thought. It is the idea you must go after,there is a story to tell.
First: What is the story
Second: How do you tell it
Be simple yet characteristic.
Sorry I did not take the time out to think out a better,more cohesive structure of words but I hope this helps! Best wishes.