Several years ago (at least four or five) I purchased a fantastic set of DVD's. The Structure of Man by Riven Phoenix. The production isn't high tech - but the instruction is SERIOUS. If you go through and do the lessons, learn the formulas (it's all about formulas!) - you will be able to draw the human figure from the bones out. Granted they are visual formulas about proportion and placement - not math and numbers.
Me? The way my life is - I'm still on lesson 10. There are over 100. I'm a little stuck here on the complexity of this piece. I need to buckle down and just do it over and over. In a short enough time that I don't forget everything I did last time.