Thursday 30 April 2015

Muscles of the head and neck

The muscles of the head and neck help us perform many important actions such as movement, mastication (chewing), speech, and facial expression. While most muscles only connect bones to bones, the facial muscles are unusual because they connect bones to skin. The muscles themselves are hard to see under the layers of other tissue, but as they contract they affect the surface layers, to give us our remarkably expressive faces. As artists we are interested in the muscles because of their role in communicating a person’s action, personality and mood.

We can divide the muscles into groups according to their function; they usually perform more than one action and often achieve their effects in combination. Here I offer a basic overview: as artists we are only interested in muscles that affect the surface, and I won’t try and outline every single muscle. For a comprehensive account of the attachments, insertions and functions of the muscles you should consult a good anatomy book like Valerie L. Winslow’s Classic Human Anatomy or Gary Faigin’s The Artist’s Complete Guide to Facial Expression. Maybe I will write about facial expressions another time as a general topic.

My paintings below illustrate most of the main muscles of the head and neck.





Muscles of mastication


The muscles of mastication move the mandible or jawbone. The strongest muscle in the jaw is the large masseter, which lies on the side of the jaw. It mainly closes the jaw and help us chew. The temporalis muscle attaches to the temporal fossa on the side of the skull and inserts on the mandible. You can sometimes see it bulge on the temple when the person is chewing. It mainly helps close the jaw.

Muscles of facial expression


The muscles of facial expression attach to the surface of the skull and insert into the face by fibres woven into the skin. When the fibres contract, the skin moves. The largest group is associated with the mouth. There are smaller groups of muscles that control the movements of the eyebrows and eyelids, the scalp, the nose, and the ear.

Eye

The corrugator sits on the inside corner of the orbit. It creates vertical wrinkles on the forehead and is known as the ‘frowning muscle’. You can’t see it in my illustrations as it sits underneath the orbicularis oculi.

The orbicularis oculi (not to be confused with the orbicularis oris) is a disc-shaped muscle that surrounds each eye socket. It closes the eyelids, acts on the eyebrows and cheeks, and makes ‘crow’s feet’ wrinkles around the eyes.

Nose

The fan-shaped procerus horizontally wrinkles the skin at the root of the nose. The nasalis or nose muscle extends down either side of the nose and flares the nostrils. Running down either side of the nose is the levator labii superioris alaeque nasi, sensibly known simply as LLSAN, which elevates the upper lip and the wing of the nose.

Slightly further out from the nose is the levator labii superioris, which elevates the upper lip. When it contracts it can produce a snarl, pulling up the side of the nose along with the lip.

Cheeks

The zygomaticus major and minor are the larger and smaller muscles of the cheekbone. The major draws the corner of the mouth outward and upward (smile); the minor draws the upper lip backward, upward, and outward (to make sad expressions).

Mouth

The orbicularis oris is a circular muscle performs various movements such as closing, compressing, puckering, and protruding the mouth. Other muscles move the lips or the corners of the mouth, helping us produce for example the range of movements necessary for speech. The horizontal buccinator (pron. ‘BUK-sinator’) muscle forms the muscular wall of the cheek and is related to chewing, suckling, whistling and smiling. When it contracts it can cause dimples on the corners of the mouth. It also helps produce expressions of contempt and smirking. The risorius draws the corner of the mouth outward and causes a dimple.

Chin

The depressor anguli oris or triangularis acts with the risorius to draw down the upper lip and close the mouth; it also draws the corner of the mouth downward. The depressor labii inferioris draws down the lower lip. In-between is a V-shaped muscle in the chin called the mentalis which raises and pushes up the lower lip, causing wrinkling of the chin, as in doubt, displeasure or determination. It is sometimes referred to as the ‘pouting muscle’.

Scalp

The epicranius, or scalp (also known as occipitofrontalis), contains two parts or ‘bellies’[1], the frontalis and the occipitalis. The frontalis extends from the hairline to the brow ridge; it draws the scalp forward and the eyebrows upward, and wrinkles the forehead. The occipitalis draws the scalp backward. These muscles are separated by the epicranial aponeurosis, a layer of dense fibrous tissue which covers the upper part of the cranium.


The neck


The neck muscles move the head in every direction, working in pairs on either side of the body. At the front, the muscles reach from the jawbone to the sternum and clavicle bones, helping us to move our jaw. The outer muscles at the side and back help move the head and neck.

The sternomastoid (or sternocleidomastoid) muscle extends from the breast (precisely, the clavicle and sternum bones) to the mastoid process of the skull and acts to flex and rotate the head. It has two ‘heads’, the medial (or sternal, i.e. attaching to the manubrium of the sternum) and lateral (or clavicular, i.e. attaching to the clavicle). The sternal head turns a person’s head to the opposite side and face upward; both heads together lift the face and tip the head backward.

In the front of the neck there is a group of ‘strap muscles’. The omohyoid muscle acts upon the hyoid and larynx. It attaches to the scapula by a part called the ‘inferior belly’, and swoops up to connect with the hyoid bone by its upper part or ‘superior belly’. Next to it are the sternohyoid and thyrohyoid which perform similar roles.

The platysma is a broad sheet that extends from the top of the chest muscle, over the base of the neck to the mandible and the corner of the mouth, overlapping the sternomastoid. (I omit it from the illustrations above as it would obscure the other muscles, so see below.) It depresses the lower jaw and draws down the corners of the lips, i.e. in expressions of fear or grimacing.


The laryngeal prominence – commonly known as the Adam’s apple – is a lump or protrusion formed by the thyroid cartilage surrounding the larynx. It is usually more prominent in adult men than in women or children. Below it is a second bump created by the thyroid gland, which is more developed in women than in men.

At the back of the neck is an area known as the posterior triangle of the neck. It contains several muscles. Its apex is where the sternomastoid and trapezius muscles meet at the occipital bone. 

What to do 


The first task is the ‘book-learning’. Get to know the information in this article, and for more detail supplement it with the books I mentioned, or others that cover the same thing. You can find lots of resources online too. The website Artnatomy has an amazing tool where you can select particular muscles to learn their locations and actions.

Fortunately, artists no longer need to personally dissect corpses, like Leonardo da Vinci, to get an adequate familiarity with the muscular system. I am not an anatomist, so my paintings of the muscles of the head above are based upon some simple research. They say nothing that is not said in countless other such diagrams. So why did I paint them? To help me learn the muscles of the head. For the same reason, you should paint them too. That’s your second task. Maybe your pictures will be more thrilling.


If you are wondering why you should bother, let me give one example of why knowing the muscles can be useful. We can smile using the risorius muscle that retracts the mouth, but this sort of smile looks insincere because a real smile involves the skin around the eyes. It raises the lips with the zygomaticus major and minor and causes ‘crow’s feet’ around the eyes using the orbicularis oculi. Knowing this sort of thing can help to make the difference between success and failure in capturing a particular expression. 

As you study the skull and the muscles of the face and neck, remember that they simply modify the solid structure of the basic form head. An illustration for teaching purposes is one thing, but a good drawing of the head should be a drawing of solid form, not a chart of the muscles beneath the surface.


[1] Some sources consider the occipitofrontalis to be a structure consisting of two distinct muscles, the frontalis and the occipitalis, rather than a single muscle with two parts.

Monday 27 April 2015

The human skull

The skull has been a very powerful symbol in human cultures, whether to commemorate ancestors or as a warning of our mortality. In the more practical world of artistic anatomy, the skull is the hard bone structure that gives form to the head.

Skulls, and the muscles and features built upon them, vary greatly, across ethnicities, the sexes and individuals, but the basic structures are the same for everybody. Realist artists need to study the skull’s parts and how the muscles fit over them, and understand how these underlying structures define people’s heads and faces as we see them. Anyone who has seen forensic reconstructions of faces of long dead people or even Neanderthals, based upon skulls alone, will have an idea of the importance of variations in the bony architecture in defining the individual features. Some people have wide heads, some have narrow heads; some people have prominent cheekbones; some have large protruding chins whereas others have hardly any chin at all. These facial characteristics are rooted in the individual’s skull.

Here we shall look just at the skull, and follow up with a look at the head muscles. We will explore in due course how to draw convincing heads of men, women and children of various ages and types – but first things first. If someone has, for example, a steep forehead, or high cheekbones, or a receding chin, you need to grasp that it is their skull that defines those features.

I will try to cover the most important aspects here, but if you want to study the skull and muscles in detail, you should get hold of a good book of artistic anatomy. There are plenty to choose from and they cover similar ground. (My personal recommendation is Classic Human Anatomy by Valerie L. Winslow.)

The skull has two main parts: 1) the cranium and 2) the mandible, or separable jaw bone. The mandible is the only bone in the skull that moves, for example when you’re chewing or talking. The skull is composed of 22 bones, not including the teeth. Almost all of them are fused together with sutures: rigid, fibrous joints found only in the cranium, which look a bit like stitches.

Here are two digital paintings of mine, a front view and a side view. (The squiggly lines that look like cracks are the sutures where different bones join up.) You should draw or paint these views of the skull too. If possible your subject should be a real skull, not another artist’s interpretation of one.



For what it’s worth you can see these two views without the annotations in my DeviantArt gallery here.

Major bones of the skull

The cranium


The cranium, which houses the brain, is made of eight fused bones.

The forehead and the tops of the eye sockets are formed by the frontal bone; this has prominences above the eye sockets called frontal eminences which give the forehead its form. At the back of the frontal bone on either side is a ridge known as the superior temporal line or temple line (marked red on the painting), which marks an important change from the front plane to the side plane of the skull. It sometimes creates a noticeable ‘corner’ on the forehead.

Top view of the cranium
The upper side walls and rear roof of the skull are formed by the parietal bones, which meet in the middle on top of the skull. The temporal line arches back across the parietals, marking a distinction between the side and roof of the skull. Viewed from the top, the skull is broader at the back, with prominences on either side known as parietal eminences.

The lower side walls of the cranium, in the region of the ears, are formed by the temporal bones. There is a large, shallow depression in the side wall, called the temporal fossa, where the temporalis jaw muscle attaches.

Projecting from either temporal bone is a ridge called the zygomatic process of the temporal bone, which links with the facial zygomatic bone to form a kind of bridge called the zygomatic arch; there is a gap between this arch and the side of the skull. The head of the jawbone fits into a hollow beneath this arch. Behind that is the auditory meatus or ear hole, leading into the ear canal of the fleshy ear. Bulging behind this hole is the large mastoid process, a point of attachment for several neck muscles.

The sphenoid bone helps to form the floor of the cranium. Part of it appears in the side walls between the temporal and frontal bones, at the temple (the area behind the eye and above the cheekbone).

The occipital bone is the lower back wall of the cranium and forms a bulge at the back of the head. Its bottom rests on the spinal column at two knob-like protuberances called occipital condyles that permit rocking movements, e.g. when we nod. There is a ridge on the underside called the occipital protuberance which is an important landmark between the back of the head and the neck, and an attachment point for neck muscles.

The face


The facial region of the skull is made of 14 bones, including the lower jaw, and serve as the foundation for the facial muscles and sense organs.

Along the upper rims of the orbits (eye sockets) are the superciliary crests which form the brow ridge. Stephen Rogers Peck (Atlas of Human Anatomy for the Artist) describes this as like “a stretched-out letter M above the eyes”. Above the nose the ridges are separated by a wedgelike area called the glabella, below which there is an indentation where the frontal bone meets the top of the two nasal bones, known as the root of the nose. The nasal bones project from under this wedge, creating a bridge for the fleshy nose.

The zygomatic bones (cheekbones) fasten to the upper jaw and create a prominence in the cheek. From the top, a spur rises to the zygomatic process of the frontal bone, forming the outer rim of the orbit. Another spur turns toward the nose, helping form the lower rim of the orbit. The rear of the zygomatic bone joins up with the ridge of the temporal bone to help form the zygomatic arch.

The maxilla bones form the upper jaw and provide the upper dental arch for the upper teeth. They join at the front, at the base of the nasal cavity, to form the protruding nasal spine.

The mandible


The mandible (lower jawbone), shaped like a horseshoe, is the only bone in the skull that moves: it can drop down to open the mouth and close up again, but it can also move forward and back and from side to side. It provides the dental arch for the lower teeth. There is a projection at the chin called the mental protuberance (Latin mentum, chin). Small lumps on either side known as mental tubercles give squareness to the chin.

On either side of the jaw, a broad blade called the ramus juts upwards, dividing into two. The front spur is the coronoid process, which attaches to the temporalis muscle for chewing. The back spur is the condyloid process, which articulates with the temporal bone via a hinge joint. The rear ‘corner’ of the jaw is the angle of the mandible. This is noticeable on people with angular jaws and is very important in defining the jaw line.


My digital drawing above illustrates the relationship between the skull and the surface features of the head and face.

On the image I have included the horseshoe-shaped hyoid bone, a bone in the neck between the chin and the thyroid cartilage. When at rest this small bone sits level with the bottom of the mandible. The hyoid, which helps us move our tongue and swallow, is unique as it is connected to other bones only by muscles and ligaments.

The teeth


People often expose their teeth, for example when laughing or snarling, so artists need to be familiar with their locations and forms. The teeth nestle in the upper dental arch (the maxilla) and the lower dental arch (the mandible), which are shaped like horseshoes. There are various kinds of teeth, which vary according to what they are for. People usually have thirty-two teeth, though they may have lost some, and the teeth vary a lot in their forms and spacing, as well as how they affect the surface forms of the face – if someone has lost all their teeth, e.g. through age, their jaw may collapse a bit inwards.

The chisel-shaped front teeth are the incisors and used for biting. There are four on either arch: the two upper middle ones are the largest, and the others are similar sized. Next in row are the canines (or cuspids), one on either side, which are fang-like and used to tear food. After those are two wedge-like premolars (or bicuspids), followed by three boxy molars used to crush and grind.

Variations in the skull


Art books, simplifying for the sake of teaching, often present us with an ‘average skull’ – usually of an adult white male. Heck, I did it myself above. Of course, every individual skull is unique. But there are particular tendencies based upon age, sex and ethnicity.

Age


The form of the skull varies a lot according to the person’s age. As infants, our faces are more compact, then expand as we grow up. We are at our best in our twenties. As an adult ages, his or her facial bones wither and become more compact again. The jawbone gets thinner and recedes.


Sex


Unsurprisingly there are differences between male and female skulls. Male skulls tend to be larger, heavier and thicker – more ‘robust’ – than female ones, with a squarer jaw and chin. The male superciliary arch is more prominent and the mastoid process is larger. The female frontal bone is more vertical than the male’s; her bones in general are smoother and more rounded.


Ethnicity


People of different ethnicities vary in their skin colour, features and build, so naturally this is reflected in their skulls. Here are a few points:

Sub-Saharan African: Tend to have more facial projection at the mouth, and wider noses. The orbits are rectangular; the nasal cavity is short and wide; the maxillae project a bit more forwards (prognathous); the teeth are large; the mastoid process is wide.
East Asian: The orbits are circular; the cheekbones are projecting.
European: Tend to have flat profiles and narrow faces. The orbits are sloping; the nasal cavity is long and narrow; the maxillae are less projecting; the mastoid process is narrow and pointed.
Native American: Tend to have wide faces. The orbits are rounded; the cheekbones are large and prominent; the nasal cavity is medium-sized; the teeth are large; the mastoid process has a small secondary projection.

The characteristics outlined above are subtle: for this reason even forensic anthropologists talk only in terms of a skull being ‘consistent with’ a certain ancestry. It’s worth remembering that there is more variation between individual members of an ethnic group than there is between the groups. Despite their diversity, healthy skulls are also all basically the same.

What to do


The bones are the framework of the head, and even the facial features relate to the bones, not the flesh. Therefore it is important to observe and draw the skull from a variety of angles until you have memorised its forms. Norman Rockwell recalled:

I had an art teacher years ago (George Bridgman) who made us draw hundreds of skulls in all positions. I felt he was overdoing it at the time, but now I realised what a wonderful lesson he taught us. Whenever I draw a head, I instinctively feel the skull structure beneath.
(Cited by Gary Faigin in The Artist’s Complete Guide to Facial Expression)

Book-learning (like this article) is all very well, but the only way to learn to draw skulls is to draw them. Ideally, get hold of a skull, and know what sort it is: what age, sex, etc. Fortunately a replica is fine! If you don’t have one available, you could try drawing from an online 3D scan such as this one (an adult male). Now draw it from a variety of angles. They don’t have to be beautifully realised paintings – quick sketches are fine. The point is to learn the skull. Observe carefully, respond honestly, and remember what you’ve learnt.

If you spend three minutes on each sketch, you can fill a sheet with ten skulls in half an hour. That’s twenty in an hour. Forty in just a couple of hours. Imagine how much better prepped you will be for drawing the human head when you’ve sketched forty skulls at multiple angles!

As an example here are some studies of my own (though not three-minute ones). Yours don’t have to look like mine. Chances are, yours will be better.


A good exercise is to find images of skulls and trace them, either with tracing paper or, if you work digitally, as an opaque layer in your drawing software. Practice adding planes or faces to your tracings.

Tuesday 21 April 2015

Introduction to drawing the head

Whenever you draw people in any detail, the point of interest will usually be the head – above all, the face. The face is our main way of telling people apart, but it is also a rich source of emotional expression. It is one of the most challenging subjects to try and draw, but we start with a couple of advantages. Firstly, artists have been finding ways to represent it for thousands of years, and we may benefit from the solutions they have found. And secondly, we have been reacting to faces from the day we were born.

Realist artists will not always have a model in front of them, of precisely the right type and willing to take whatever pose is needed, so we need to understand the head intimately so we can draw it from imagination. Ideally we achieve this by combining a command of technique with emotional expression, and, as always, sharp artistic judgement.

Technique


Through study and careful observation, we can learn to create a solid-looking head in any position we please. We begin with various ways of conceiving its basic form – a sphere, an egg, a block – as this is the easiest way to grasp its three-dimensionality and its relationship to the rest of the body. Then we need to develop our awareness of the structures and forms that together make up individual faces.

We need to know the human skull: how it looks from different angles, and how it relates to the surface features. We memorise the proportions, the planes, the muscles that govern facial expression, and the various specific characteristics of the eyes, noses, mouths and ears. By drawing a great many heads from various angles, we memorise the basic relationships and proportions so we may reproduce or violate those tendencies as we wish.

Humanity is remarkably diverse. Some artists may be able to meet their artistic needs by producing the same sort of character over and over again, but to be versatile and reproduce the variety we see before us, we need to observe the physical differences between male and female, young and old, lean and fat, (conventionally) ugly and beautiful, and so on, and know how to recreate these characteristics in our drawings.

Expression


A human head is more than a block or a skull or an accumulation of properties. It is the focal point of a complex, living being. Realist artists must study how the muscles and features change to create particular expressions. We have to judge which emotion or combination of emotions, or which angle of the head, best convey a work’s message, or capture a particular individual. It is easy to mystify this ‘seeking after the soul’ but it is essentially a question of observation and technique.

Try to do people justice. The heads and faces of human beings are alive and opinionated and expressive, and they demand a reaction from the rest of us. They are a central part of our daily social life. This is why, in realist art, being able to draw them well is so important.

What to do


If we have an internet connection we have access to an infinite supply of images of heads of every kind, either photographic or artistic, ranging even to the non-human (orcs, trolls and other anthropomorphic fantasy creatures are just variations on human beings). But if you really want to become expert in drawing the head, draw from life whenever you can.

Our goal is to keep studying until we can confidently draw, from our imagination, any sort of person we want, in any position we want. The next few posts will look at how to get there.


Monday 20 April 2015

Heads practice


A collection of heads, drawn from imagination. Just practicing, using the method described in my last post. Photoshop, Wacom tablet.

Friday 17 April 2015

Drawing simple heads

In his 1939 book Fun With A Pencil, the American illustrator Andrew Loomis described a simple method for drawing heads. The book is dated, but the method is timeless.

Anyone can do it. All you need to know, he explains, is how to draw a circle. Here’s mine. It’s hand-drawn, not so it’s not a perfect circle, which is fine.


The secret of drawing heads – the secret, in fact, of drawing anything – is to describe it using simple forms which you are familiar with, and whose behaviour you understand. By building up simple forms, we can arrive at very complicated ones.

We can conceive the human head as basically a kind of ball. By drawing a vertical and a horizontal line on our circle, we give ourselves some construction lines.


So far our circle is a flat disc. Turn the ball, and the construction lines turn with it. Rely upon your eye to tell you where the lines go. With three simple lines we have created the illusion of a three-dimensional object. If it helps, mark the axis so you know which way is ‘up’.


These lines act as a guide to where our ‘real’ lines should go. We can turn the ball in different directions and always know where it’s pointing. The better you can knock out basic construction balls like these, the better you will be at drawing heads, so practice drawing a bunch of them. Fill a sketchbook page. Here are some I did in pencil:


By building up your simple forms, adding additional ones to this basic ball “like lumps of clay” (as Loomis puts it), you can create solid, realistic-looking images. When your drawing is finished and the construction lines hidden or erased, no one would guess how easily the effect had been achieved.

Get drawing.

Draw faintly while sketching things in, then draw more heavily once you have the lines you want. In the example below, the sketchlines are shown in blue.

1. Start by drawing a ball. Again, don’t worry about making it ‘perfect’. If anything, imperfection adds character. 


2. Add vertical and horizontal lines, like on the construction ball, to show the direction your head is facing in. Mark the nose in the middle, and crosslines above and below for the eyes and mouth.


3. Sketch in the features: the eyes, brows, mouth etc. You can add other shapes as you please – see how the nose and chin are basically made up of ball shapes.


4. Draw it in, then erase your construction lines. You have drawn a simple head!


Don’t be discouraged if your first efforts aren’t the greatest. Every artist has to find their way in the beginning. Keep drawing more heads and you’ll get the hang of it. I’ve done some more examples below.


Remember, the construction ball is designed to help you create an illusion of three-dimensionality. Using a dotted line, we can ‘draw through’, i.e. indicate the sides we can’t see, helping us understand the form.


You can add another vertical line to the construction ball down the side, dividing it into quarters. This shows you roughly where the ear should go.



Build shapes onto the construction ball

Try to use shapes that give you the effect you want, and vary them so that every head is different.


It’s a bit boring to draw the same generic person over and over again. There’s no limit to the range of angles, expressions, styles and characters. You can draw young and old; male and female; black and white; happy and sad; curvy shapes and blocky shapes; smooth cartoony lines or scribbly lines. The construction ball is a guide, not a strait-jacket. You’re free to play with it, to break out of its bounds. What matters is that you get the head you want.

This method is great for quick, cartoony heads. There is an awful lot more to drawing the human head, so maybe I’ll write more another time. Meanwhile, below is a bunch of heads I’ve drawn myself using this approach. I like to work digitally, so these were drawn in Photoshop using a Wacom Intuos tablet.