Corel Painter 11/Wacom Intuos 5 med tablet
30 sec sketch
I can see the joints very clearly and that tells me a lot about the attitude of the model. It is a good underdrawing and communicates the internal structrure of the figure. Try drawing all the load-bearing lines in one motion or using the side of your pencil to render a part of the drawing you want to emphasise with visual weight.