Well, I'm sure this isn't exactly the type of image you'd expect to find on this here Beefcake drawing blog! My previous post where I played around with straight lines vs. curved inspired me to try a little experiment: to draw a figure alternating, as much as possible, between straight and curved lines. You might be inclined to call me out on a few of my curve-ishy "straight" lines...but I would argue with you that the area in question leans more to the straight and, therefore, counts as such :)
Now, I'm a cartoony cartoonist so my technique does favor the more exaggerated. There are certainly very few(if any) completely straight lines in actual human anatomy. But drawing is all about interpretation of the actual/real. Even in the most realistic of drawings there is stylization going on (meaning that the artist is making choices in what and what not to include in the interpretation of the three dimensional world onto the two dimensional drawing surface).
Whew! That's nearly enough "Art" theory for me! As one of my college art teachers used to say, "Talking about Art is like Dancing about architecture." *
Here's a fleshy colored doodle to put us back on the Beefcake track. This was another experiment, however. The Red line running up the front-side of the figure was my starting point. I wanted to build a figure with as much of his form "locked" to a solid perpendicular. When I'm drawing from life I'll sometimes look for such "through lines" on which to build the rest of the figure.
* (As I know there are both artists AND dancers who read my blog, I type that quote with tongue firmly planted in cheek ;)