Awesome form! Take a quick look at the left scapula on the male model - If you look at the other posts on this page, the left shoulder blade is much lower than how you have it depicted. - From a fellow student. Cheers!

First off, your lines are nice and fluid. I'm guessing these are digital as well. So, double-kudos to you. I see some proportion issues; however, that is to be expected because these are gestures. I took 2 minutes to lay in your first pose. I drew the sacrum bigger than you have. In all, very nice try.