Very nicely drawn. But as for usability, it has zero value. It is your practice but it doesn't help anyone to get better at drawing. Only deep understanding and study of anatomy and human body for at least 2 years can help someone to be able to draw it by themselves.
All of your tutorial are very helpful! thank you! once i get some extra time, i'll draw something up and i'll post it on here, linking it back to you, if you don't mind the extra attention. ^^ Thanks again!