Friday, January 25, 2013

More Random Landmark Sightings in the Art of Old Friends

One of my favorite things to do as a medical artist is observe other artists' figure work and search for anatomical landmarks. I especially enjoy doing this on stylized figures that are exaggerated in one way or another. I've done this before with a friend's drawing in a post called Sternocleidomastoid: Don't Forget the Cleido! This post featured the art of my friend Shawn Campbell, a wonderful artist and one of two great art friends I was fortunate enough to meet in middle school (back when it was still called junior high school.) His work is not only beautifully rendered, but anatomy is always sound. And as I mentioned in that post, knowledge of the human skeletal and muscle structure is not only useful when drawing realistically but also when drawing a human (or humanoid) with stylized or exaggerated features.

The other lifelong art friend I was fortunate enough to meet at Lincoln Junior High was Chris Boyd, also known as Crazy3DMan. He and his wife Michelle have also been lifelong art friends with whom I've shared friendship, ideas, meals, conversations, rants and of course, art. Today Chris is a freelance artist who specializes in character design, illustration and concept art, which he creates with both 2D and 3D media. Chris also co-founder of Squirtgun Studios, a Chicago studio that specializes in concept, design, illustration, motion graphics, photography and copywriting. 

Like Shawn, Chris's figure work, no matter how stylized or exaggerated, is always anatomically sound. I was looking at some of his characters recently, and this one caught my eye. The first image shows it alone, and the second has labels I added to show all the wonderful, accurate anatomical landmarks Chris included.

Chris's original soldier illustration.

Chris's soldier sketch with subtle but accurate anatomical landmarks labeled.

Although the smallest pencil marks can signify these surface landmarks, it's still so important that their shape and location are drawn accurately. And they are here. Let's look at some of them more closely.

The image below zeroes in on the thyroid cartilage, the medial epicondyle of the humerus, the head of the ulna, the extensor digitorum tendons, the olecranon process of the ulna, and the lateral epicondyle of the humerus.

The thyroid cartilage is pretty exaggerated on this dude. Which is totally fine, since it's typically larger in an adult male. This is because the thyroid cartilage houses the larynx which manipulates the volume and pitch of our voice. A deeper voice warrants a larger larynx and a larger thyroid cartilage in which to house it. You can read more about this in an anterior neck post called The Anterior Neck: Theme and Variations. 

On the back of the soldier's right hand, we can see the tendons of the extensor digitorum muscle. The muscle itself runs along the dorsal side of the forearm, but its tendons, which insert onto the dorsal side of digits II through V, split apart and become visible on the dorsal surface of the hand. We can see three of these tendons in Chris's drawing. You can read more about the extensor digitorum muscle in my post The Dorsal Forearm Part 2: Which Side Are You On, Anyway? and more about its tendons in particular in The Dorsal Forearm: One Last Encore.

On the dorsal surface of the soldier's left arm we can see evidence of the extensor carpi ulnaris muscle and its tendon. The muscle body is more proximal on the arm and reads as a small bulge with a shadow below it. That shadow is a small furrow that divides the forearm extensors from the forearm flexors. More distal on the forearm, we can see the long tendon of this muscle, just before it runs over the head of the ulna. You can also use the above links to find out more about this muscle and its relationship to the head of the ulna. And to read more about the crease between the two forearm muscle groups, check out The Dorsal Forearm Part 1: Compartment Search. 

The last landmarks we can see in this close up are the lateral epicondyle of the humerus (just barely) and the olecranon process of the ulna. The olecranon process is simply the portion of the elbow we lean on. The lateral epicondyle is just lateral to the olecranon process and is often barely visible when the elbow joint is extended and the arm is straight. But when the elbow joint is flexed and the arm is bent, the olecranon process dips down lower and the lateral epicondyle sticks out a bit. Most artists forget to show both bumps when the arm is flexed, but not Chris. In this situation, the elbow will have two slight bumps-- one more proximal, which is the lateral epicondyle, and one more distal, which is the olecranon process. You can read more about these two structures at The Elbow Joint, Part 1: Anterior View, Supine Position.

Below we have a close up featuring the last two landmarks spotted in Chris's image.

With one very subtle line, Chris has shown the location of the medial epicondyle of the humerus (as opposed to the lateral, discussed above. Unlike the lateral epicondyle, the medial epicondyle can usually be seen no matter what position the arm takes. This epicondyle appears as a small bump on the inner elbow. Just proximal to this bump, we can see a long muscle attaching to it. This is most likely where we'd see the medial head of the triceps muscle, but I didn't label that here. The triceps is one muscle this blog has not adequately addressed just yet.

The last two landmarks shown in Chris's sketch are on the soldier's right ventral wrist. There are two very small marks indicating tendons that can often be seen there. You may want to scroll up to the unlabeled sketch at the top of the page to see these more clearly at first. The second of the two marks is very subtle and difficult to see at low resolution. These two tendons are those of the flexor carpi radialis muscle and the palmaris longus muscle. While the latter is missing in some individuals, it is most commonly present. And when it is, it's often easily visible. The flexor carpi radialis tendon is always there, but it may not appear as superficial. You can read why at my very first post, The Ventral Forearm: What are those Tendons?

I'll be back soon. The next post will probably revisit the elbow joint. I started that series awhile ago and completely forgot about it. Also, requests are always welcome. Until next time!

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