How To Draw Muscular Arm

Cartoon Arm Formula

It's odd to have a body without arms. Arms and hands are very expressive parts of a figure. We'll be tackling hands separately. In this lesson we'll be focusing mainly on arms.

Arms, for the most part are very simple to draw. It's when you want to get muscular that things get complicated. Either way, drawing arms start off very simply.

In this lesson, we'll be tackling:

Simple Cartoon Arms
Arm Drawing Formula (two line arms, arms as tubes, slight tapering, rhythms).
How to Apply the Formula to Different Cartoon Styles.

Let's begin with the most basic of cartoon arms...

Simple Cartoon Arms

In their most basic form, cartoon arms can be simply broken down to rubbery rectangles. If you want to add more dimension to them you can make them tubes or rubber hoses.

When these types of arms bend you can leave have them curve like a hose or you give them more of a corner. Depends on the style you're going for.

You can make them thin or fat. Straight or tapered.

You can vary the type of lines that make them up. More often than not, putting straights versus curves is an appealing way to draw them.

When creating arms for simple cartoon characters, simply experiment until you find a variation that you like.

It's only when drawing cartoon characters that are bit more naturalistic that things get a bit more complex. As we will see below...

Arm Drawing Formula

Once you want your cartoon arm become more natural looking, it helps to have a simple formula as a base for the different variations. Surprisingly, it's not very different from the simple cartoon arms drawings above.

The most complicated cartoon arms can be broken down to a slightly tapered tube when it's stretched out.

When it's not, you simply draw two slightly tapered tube connected at the bending point.

The real trick to it though is to not be mechanical about the way you draw the tube. A good rule of thumb is to give the tube a very subtle curve of some sort. Either an slight "C" curve or "S" curve. It gives an arm an organic feel from it's very foundation.

Once you have this foundation, you can start adding solidity.

First, you want to make sure to find where your the forearm ends and the upper arms begins. An proportion rule of thumb is that from the top of the shoulder to the elbow, is longer than the whole forearm. It's in fact as long as the forearm and the hand together, if the hand was balled up to a fist. However you can modify this if you choose to design any type of interesting arm. You're the draftsman.

Second, turn the two graphic lines into a cylinder by adding directional lines. These lines show you the direction of the perspective you the arm you're drawing. BE CONSISTENT. If you're indicating that the direction of the arm is going in one direction, it's impossible for you to see an other part of the same arm going in the opposite direction, without it turning:

This is where practicing your forms comes in.

The guides also help when putting details on the arm, like watches, sleeves or muscle details. They help you see what direction to draw them in so they are consistent with your established arm perspective:

Once you've go this down, you're pretty much done. The rest comes down to your knowledge of human anatomy and muscles.

In case you don't know any of that, I will give you some tips.

As a general rule of thumb, avoid symmetrical arm muscles. Arm muscles tend to look very inorganic when they're symmetrical. Symmetrical muscles sometimes look like you're drawing a snow man rather than arms:

I'm NOT saying you should never draw them this way. There's a style of cartoon that works really well with muscles that looks this way simply because they're very funny looking. For cartoons like that, it's totally fine and very fun.

However, if you're trying for a more naturalistic organic look, this may not be the best solution.

Arm muscles look far more natural when they rhythmically interlock and are asymmetrical. Which leads me to another good rule of thumb when placing anatomical bumps on an arm: Stagger the bumps:

Yet another way to go is designing, Simple vs. Complex muscle groups. Simplifying one side and adding a bit more complexity on the other side, can add interest and often feels natural and looks cool.

Now let's take a look at how this formula works in different styles...

Applying the Formula

As before I want to show you that this simple formula can be the foundation open which any style can be used. So let me show you:

Freddy Moore Style

The Freddy Moore style has two types of arms. The Disney type arm and the Looney Toons type arm.

The Disney type looks a similar to number 1 above. It looks very natural and muscle symmetry is avoided. The lumps tend to be convex.

On the other hand the Looney Tunes arm, which is number 2 above, a bit more simple. It often uses a concave line in the back of the upper arm. This isn't meant to represent any real world muscles but rather, it's meant to add an interesting design aesthetic.

Bruce Timm Style

The Bruce Timm Arm is simply a "B" shaped arm. (1) A simple (gently curved) straight in the front with two "C" curves in the back. There is some variation in the "C" curves. These curves are meant to simplify and represent the complex muscles of the arms.

Male arms more often than not tend to be wider that female arms in this style but otherwise, they are essentially the same.