Some models are a joy to draw. One of those is Stephen, whose lean form creates Egon Schiele-like results. His skeleton is clear under the skin, so when he lies, his bones create a landscape of peaks and troughs.
I find it’s very useful to draw someone so lean to understand the structure of the body, to see where the muscles join and overlap and stretch over the frame.
When I draw someone like Dave (also a joy), who is bigger and more muscular, the knowledge I’ve gained from drawing Stephen helps me to understand the twists of the hipbone and the tautness of muscle over the ribcage.
Here (above), the tension of Dave’s lifted arm pulls up his ribcage, and below, his weight is placed on one point, driving his weight into the ground and shifting the balance of the body over his fist.