Drawing anatomy

With my test animation I have realised I need to draw the human anatomy a lot more. Basically I have the anatomy down for most parts, there a few things I realised I do not know how to draw. Well I could draw it i just would not be sure if its correct. Also following Fraser MacLeans talk I was really inspired to work on my drawing skills, since shading has always been my weak point. Also my teacher used to say I have very hairy lines. So I decided some practice drawing would do me some good. The sketches ended up looking really good, so I put them up on my art book. So what I have been doing is making at least one sketch a day-