I need help. (Not 100% sure if this is the right forum for this... erk.)

I would like to know if anyone has any suggestions or references to help me out with this. To start off, I'm taking an anatomy class which is basically focused on rendering. Find a picture of a skeleton torso and render it perfectly, ect. While this is... um, okay, I don't think it's the right method for teaching anatomy for me. I need to know how muscles move when in this or that position, and why. How they connect, twist, bunch and stretch. Is there a good book or any instructional material on the mechanics of the human body, preferably with lots of pictures?

I have several artist anatomy books, but they mostly amount to pictures of models to reference. I also have some medical ones, which are good at showing the inner workings of things but notsogood from an artist's point of view, as I'm sure yall know.

I feel like I'm missing a big puzzle piece here, and putting it in place would really help bring my figures to life.