Exercise 0H: Upper Body Anatomy 2 - Pectoral muscle

Hi there! This week’s lesson is on how to draw the chest area. To do this, we’ll look at the pectoral muscle, and how the pectoral muscle is shaped.

Let’s start with what we saw in last week’s lesson.

This is the upper torso, aka the chest! There are three major pieces here that you can use to measure and layer muscles and clothes.

1. The neck - a cylinder between head and ribcage
2. The ribcage - a flattened eggshape, which you can shade and contour like a sphere
3. The shoulders - small spheres which connect to cylinders for the arms.

The pectorals, in blue, connect the top of the ribs to the lower edge of the shoulders. They stretch from the center of the chest across the front of the upper arm.

Let’s draw some contours over the pectoral to show how it curves. On the right hand side is a frontal view — The contours look straight from this view, but on the left…

… the blue contours do curve out slightly! This is because the muscle is layered on top of the round ribcage. The red contours on top of the arm are hooked slightly, because they are curving up and under into the armpit.

Girls will have a little more going on there, of course, so let’s look at the difference. The contour lines show how a lady’s lumps start over the pectorals and become 3d. These contours will give it form, catch light and cast shadows. The red contours on the side still help from the armpit, of course!

<– click for girl version only

When it all comes together, you can start putting clothes on top of the chest. By knowing where the contours are on the chest, we can put shadow that stretches evenly across the front. We can add shadow on the sides, where the round ribcage curves to the back. And, for the sleeves, we can make wrinkles and shadow where the armpit is!

Next week, let’s look at the shoulder muscles of this girl and give her some cool armor! See you then!

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