How to Design Muscles and Tendons – Drawing Anatomy for Artists


Hello, my name is Stan Prokopenko and welcome
to Proko! This is the second part of the Intro to Muscles Lesson. Let’s take a step back and look at what
a muscle actually is. There’re two parts, the belly of the muscle, and the tendons.
We’ll start with the belly. Belly of the Muscle The belly is comprised of muscle fibers. They
usually follow the axis of the muscle, though there are exceptions. More on that in a minute.
Muscle fibers group into bundles, which can be seen on the surface form, usually when
the muscle is active. Here’s something cool. Wrinkles and skin
folds always happen in the perpendicular direction to the muscle fibers. Pop quiz! The muscle of your forehead lifts
your eyebrows and causes horizontal creases across your forehead. What direction is the
muscle fiber? [Skelly Calculator Scene] It’s vertical… The muscle fibers are vertical. When you flex a muscle, it’s the belly of
the muscle that shortens, not the tendons. And when you stretch, it’s the belly of
the muscle that you’re stretching, not the tendons. Tendons have their own thing going
on. Tendons they do have personality. The shape, length,
and thickness varies from tendon to tendon. Tendons are thick enough that they’ll add
mass to the surface form. They can appear as these long tubes that we typically think
of as tendons. When nearby muscles are bulging out, tendons appear as slightly recessed planes.
These forms can help you identify where a muscle is. By the way, “tendons” are made of the
same fibrous tissue as ligaments and fasciae, but “ligaments” attach a bone to a bone
and “fasciae” attach a muscle to a muscle. An aponeurosis is a special type of tendon
that’s large and thin. For artists, that means that it won’t obscure the form of
the muscles beneath it.  For example, your lower back is actually covered by your lat’s
aponeurosis, but you’d never know, because aponeurosis…es…are so thin, and the forms
of the deeper muscles show through. Sometimes tendons are embedded inside the
belly of the muscle, which is called a tendinous intersection. All of the divisions on the
rectus abdominis that cut out the 6-pack are a result of these tendinous intersections. What’s interesting is… the length of a
muscle belly versus the length of the tendon varies from person to person. Bodies with
proportionately longer muscle fibers tend to look more graceful. Even if the individual
is very muscular, the muscles appear to curve in and out in elegant, slender slopes. Longer
tendons means that the muscle mass has to be shorter, so muscles appear as abrupt protrusions
and depressions. The overall look is bulky with contours that look like a mountain range. Here’s an example of a superhero with longer
muscles. And here’s an example of the same superhero with shorter muscles. Muscle Groups We’re almost done! To wrap up this intro
to muscles, I’m going to give you a tip for simplifying muscles in your drawings.
Muscles nearby each other that have the same function can be grouped together, like how
we group the “quads” in the leg. Although technically four individual muscles, they
all have a similar function, so they’re all at rest at the same time. And when they
rest, they blend together and appear as one form. Muscle groups are separated from each
other by a soft surface furrow. Types of muscle… available in the premium
section. If you’d like to learn about the 8 types of muscles found throughout the body,
head on over to proko.com/anatomy. Get the premium anatomy course for access to the extended
videos, 3d models, and more drawing demonstrations. C’mon check it out! it with your friends, and if you want to be
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