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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Exercise 0G: Upper Body Anatomy 1

This week we’ll be starting an advanced lesson with Anatomy! We’ll talk about how to draw the head, neck, and shoulders. Let’s take a look at this full body pose, and review our previous exercises. Keep an eye out for today’s key point, the shoulders!

First off, let’s consider the measuring and proportions from Exercise 0B. We’re using 7 heads here, instead of 7.5, but we’re keeping the legs at 4 heads. It makes for a more youthful figure!

To understand the upper body, get used to measuring in heads by using the head shape for the ribcage. Separate the head and ribcage by about half a head.

The shoulders are going to float above the ribcage, but not as high as the chin. If the neck was half a head, the shoulders are going to be spheres about a quarter (1/4) of a head.

And, focusing in for a moment, you then use the muscles to connect the pieces!

But here’s today’s key point! The shoulders can move in quite a range around the top of the ribcage. The shoulders can be raised upwards by the trapezius muscles, also known as the shoulder muscles… Let’s pull those shoulders up… And see what happens…

(click to see the difference)

Now, the pectoral muscles (front chest muscles) have to stretch up to the shoulders. From the back, the latissimus dorsi are also stretched up. I’ve inked between the pectoral and latissimus muscles, because that’s the “arm pit”, a gap between those two muscles and underneath the shoulder.

Did you catch all that? Focus on the shoulders for now! We’re going to continue talking about the different muscle groups next week. We’ll draw contours over them to study, and then use those contours to draw clothes too!

See you next week!

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Body Expression Lesson at the Holiday Anime Faire

Hello, this is Karen chiming in! Ian was a great model to work with in the class. I hope you learned that observing people in real life can really improve your own character drawings. Using stick figures is a very handy and easy way to start. If you have any follow up questions, please ask in the comments.