In this penultimate Human Anatomy lesson, we'll look at some things that didn't fit into the main lessons but are very useful to know.
A Couple of Details
Around the Shoulder
Below you can see how the muscle lines joining the arm to the torso look when the arm is in different positions. They are the same with females, where the pectoral line simply flows into the outline of the breast.
The underarm line always tucks in under the pectoral line, but is in front of the back line if that is visible.
The trapezius line goes behind both the neck and the deltoid line.
When the arm is held out, the biceps line is entirely in front, overriding both deltoid and forearm. Note how it flows into the pectoral line, even if their connection is not visible (it can be, in muscular or sinewy bodies).
When the arm is raised, the trapezius line is still behind and can altogether disappear if the deltoid is very bulky. Note how that muscle bulges in this position—even if not big, it remains a mass, and it is displaced in the movement, not compressed into oblivion.
In this position, the pectoral line tends to disappear (it can still be hinted at with shading, just not a sharp line). Even breasts (depending on their size) tend to lose much of their outline in this position.
The dotted lines hint at the position of the muscles underneath. The two inner lines indicated here are both in front. Don't confuse the outer line with the line of the back (1), which can never cross in front of the arm; here it is a muscle that is pulled out slightly when the arm is raised.
Around the Elbow
The elbow is a hinge-like joint, which results in a peculiarity: it is pointy when bent, and hollow when extended. The diagram below details what happens:
The ends of two bones (or condyles) are prominent in the bent elbow, so the "point" is actually double, and looks different from different angles. In this profile view, there is a prominent point on the lower side, but there is also a bump (1) that would catch the light.
When the arm is bent in this position, the prominent point seen previously appears more distinct, almost sticking out. The bump, on the other hand, is now lower, forming a blunter point. Comparing these two positions, remember that the pointier bump isalways in line with the underside of the forearm.
If you look down at your elbow from this position, this is what you see: not a point, but more of a wedge, that sticks out moreinsidethe arm.
With the arm extended, the bumps disappear (except to the touch), but the bone structure creates hollows instead. Depending on hand position, they can look distinct as shown here...
... or the arm outline can flow into the hollow as in this example. These are simple solutions that look right, but it's useful to study the changes in a mirror!
A Couple of Movements
Steps in Walking
Below are the four main steps in walking. In a full walking cycle, which is mostly of interest to animators, you would see eight of them as they are repeated on the other side; for our purposes it's enough to have these in mind.
The most expressive is step 1, but if you're drawing several people walking, you don't want them to all have the same step; that's when the less expressive steps come in handy.
In the walk, the spine is upright. Bending forward means walking faster, but there is a limit—a walking person doesn't bend as much as a running person, because they would topple over!
Note also, in the walk there isalwaysat least one foot on the ground, and a brief moment (in step 1, called "contact") wherebothfeet touch the ground.
The hand reaches its furthest backward position in 1, its furthest forward position in 4. Shown above is an average amount of swinging, but this can vary and be exaggerated for a cartoonish effect.
The hands swing opposite to the movement of the legs: right hand is forward when right leg is backward, and so on.
Steps in Running
For the run, I'm showing five steps as it's more dynamic, plus a sixth that is really step 1 but on the opposite side.
1 and 4 are the most expressive, while 2 (sometimes calledrecoil) appears almost static. 3 feels slow, and 5 is confusing on its own—is that person jumping or running? So even more than in the walk, one has to choose carefully which step to draw, and save some of them for when diversity is needed.
In the run, the inclination of the spine depends on speed. The diagram shows an average run, reasonably fast. A jogger would be more or even completely upright; a racer can be almost horizontal, especially in a cartoonish style that exaggerates everything. Notice also there is more swing from left to right than while walking: the chest opens to one side in 1 (R), then the back is turned to us in 1 (L).
In contrast with the walk, there'snever more than one footon the ground, and in step 5, both areoffthe ground.
A change in level is much more noticeable than in the walk. Step 2 is also called the "down", because that's when the head is lowest; step 4 is the "up" for the opposite reason.
Note that step 1, when the foot first touches the ground, is when the hands reach their outer limit—that's the furthest they get from the body. The exact distance depends on how fast and/or dramatic the run is!
The hands still swing opposite to movement of the legs.
A Couple of Other Things
Level of Detail
A question that sometimes comes up is: "How do I simplify the features with distance?" There's no hard rule, as the style of drawing is a factor, but as a matter of reference, here is the hierarchy of loss (or addition) of detail that works for me with my style. These images are extracted from my comic book, and I show them in colour because sometimes, colour on its own can define features in a subtle way when lineart needs to be omitted.
Images 3 and 4 are the scales that come up the most for me, so they show the average level of detail: the features are well defined, including the lower lip, with extra lines possible for more definition when appropriate (eyelids, nostrils, ｅxpression lines when needed). Note how, for this character, the eyebrows and beard are not defined with lines, because he's fair and they're supposed to be a "five o'clock shadow".
2: Go up one level, and the facial hair is still not outlined, but has acquired detail in the colour itself. The eyebrows, however, can no longer be unlined colour, since the eyes and nose have more definition; they would look painted on the forehead!
1: This is the maximum detail I use in this particular style. The lineart defines everything there is to define, even the bruise, which would otherwise look like an ink stain rather than the slight swelling it really is. Normally shading would come in as well, and would be particularly detailed here, as opposed to vague shapes in the smaller scales.
5: Going smaller than the normal scale, I lose all detail in the nose except the end of it, where the nostrils are no longer distinct. The lower lip may or may not be indicated. The eyes could be mere dots at this scale, depending on how intense I need the ｅxpression to be (dots are much less expressive). The facial hair is now really hard to distinguish from the skin tone, which is fine because it would be in real life too from this distance!
6: This is the smallest I would go before leaving the face altogether blank. The features are now basically just dots for the eyes, with eyebrows (even though their colour makes them almost invisible here) and a line for the end of the nose. The mouth is not shown unless it's wide open to scream, and even then lips would not be drawn. Were this a female character, I would omit the nose as well, to preserve the delicacy of the face, and maybe indicate the lips with a red shape instead.
An additional tip, if you happen to draw digitally, is to keep the same pencil size throughout your virtual sketching. When drawing on paper you don't even have to think about it, you just know when you can't draw the same level of detail, and it becomes largely instinctive to just input what you can. The limitations of the tool and of your sight automatically help you draw the right amount of detail. You then ink your pencils (on paper or digitally) with pens of varying thickness, yes, but the level of detail you're working with is correct. People who draw and ink digitally sometimes fall into this annoying pitfall: as they zoom in and change the size of the brush at will, they completely lose sight of the overall scale, and end up drawing far too much detail, or drawing too coarsely. Awareness of this is a mark of know-how!