Greetings, was talking about facial expression today and remembered I started this e-handout but never finished it up to post. So without further ado, a quick guide to the muscle of expression.
Okay, it's a skull. Or not just a skull, a LABELED skull. Oh yeah! Neat huh? What's that? Where's the muscles? I know, this IS supposed to be a "Muscles of Expression" e-handout so...
Look, there they are, Technicolored for your convenience (actually they are all different colors, really, that's why Colorado is really pink because it's pink on the map. Anyway, I didn't draw many deep layer muscles because, well, they are deep layered muscles and not really vital to understanding facial expression as they act to "assist" the upper layer muscles. The buccinator (sounds like buck-sin-a-tor not like 'buccaneer') is about as deep layer as I got here. The levator palpebrae is under the orbicularis oculi and opens the eye, it's a deep layer muscle too. You'll notice that I included origin and insertion of these muscles (labeled as "O" and "I") because it's very important to know how the muscle works and therefore changes to the face so it can express. Origination of a muscle means where the muscle "pulls" to. Think of origination as the place where you dig in your heels at the start of a tug-o-war. Insertion means the part that is being pulled. If you were in a tug-o-war against a kitten, you would drag the kitten toward you....unless it was a REALLY big kitten, but that's another story.
Let's go back to the skull, I have isolated the muscles and drawn what those specific muscles are doing. Refer to the labeled skull and labeled muscles images above to see where everything attaches etc. Here is an expressionless face that will be overlaid on the skull. In the images that follow, you will see this face (shown below) and on the left of the face, the muscle or muscle groups will be shown in action. Note, generally the muscles act as a group which also hides a specific muscle's action so the isolated versions may look out of context or even silly.
When applying expression, it's extremely important to learn the anchor points of the face, these keep the face in proportion even through many emotions may be expressed in a series. Because of the pliability of the face locate the parts that don't move so the rest doesn't get all "wonky".
The main anchor points (shown above) are the outermost points of the eyebrows, the corners of the eyes themselves, the connection of the septum and philtrum (the base of the nose) and back up. The upper teeth or maxilla The hair line usually stays in the same relative spot as do the cheek bones but that depends on the character. The points mentioned will always be the same in relationship to the entire face. If you pay attention to the triangle made from these anchor points, you get what many of my animator pals call the "Bermuda Triangle" of facial expression as shown below. Keep everything in this triangle in correct proportion and it will be much easier to keep the rest of the face in proportion.
To get started on the topic of muscular expression, I dropped in the frontal portion of the epicranius. This is the muscle that is associated with movement of the eyebrows. Expressions of fear and surprise use this muscle instinctively. If some outside stimulus is sudden or scarey, the epicranius immediately responds by pulling the eye brows upward out of the way so the eye can open wider and let in more information to better judge the situation. Raised eyebrows also express questioning, confusion, contentment and satisfaction among others.
Below the eye is wide open as the levator palpebrae (not shown) lifts the upper eyelid while the epicranius pulls the eyebrow upward.
The corrugator (below) which sits right in the 'notch' between the brow ridge and the nasal bone works to pull the eyebrow inward toward the nose, expressing anger, concentration, contempt etc. The epicranius and corrugator work together to pull the eyebrow up and inward to achieve a look of sadness or longing.
Which brings us to the procerus (in magenta) and nasalis (lavender). These are the 'nose wrinklers' which become especially prominent in expressing disgust. A yucky flavor, a nasty smell, a tall fat guy in a Hawaiian shrit - all of these make the nose want to wrinkle. These two muscles also work with the corrugator to aid in expressing anger as in the tightness of the center of the face.
The Orbicularis Oculii sits around the orbital rim of the eye socket it acts as an "activator" for other muscles such as those that make the face smile.
in addition, I drew an example of the eye closed. The closed eye is the relaxed levator p. as shown below. This is why you close your eyes when you sleep or why it's hard to keep your eyes open when you are tired, your levator p. is tired and can't keep the eye open.
Besides making the nostrils flair, the group of muscles known at Quadratus labii superioris work to activate the cheek and lips into the start of a smile or flesh under the eyes into a squint. these really help to pull the corners of the mouth outward to assist in smirks and also consonant formation also known as blend shapes or mouth shapes. There's another handout up here about just that. May post something newer and better...later.
Ah, below we have, the smile muscle (the zygomaticus, in orange) and the sneer muscle (the caninus, in red), two opposing forces doing constant battle. The smile verses the Idol, the "Billy Idol" that is. go back and read the origin and insertion and you'll get what I mean. The caninus also activates disgust and contempt.
Now the muscles that bring the face (and you) down. Or, at least show it. Below is the triangularis which works to draw the corners of the mouth down and assists in closing the top lip on the bottom lip.
And the quadratus labii inferioris (dark yellow) and mentalis (green) are the ones that really make you frown. The QLI pulls the lower lip down and forces it outward while the mentalis really pulls the lower down and rolls it outward away from the teeth and causes the wrinkes in the chin.
Below is one example how all the m,muscles of the face work together to get the face to express an emotion. Here is disgust. It could also read as bitter as in you just tasted unsweetened chocolate powder.
The muscles of the lips are also know as the orbicularis oris (in brown). This muscle closes the lips and is mostly responsible for mouth shapes. And for puckering up, how about a kiss? Mwwwah! The buccinator (dark green) draws out the corners of the mouth and pulls in the cheeks when you're standing front of the mirrow looking to see if you have lost any weight this week. This is also the muscle that causes the dimple just beyond the edge of the mouth. So those of you who have dimples, here is the muscle responsible.
Thought not directly responsible for expressing emotion, the temporalis (which is actually a chewing muscle) has been known to flex showing tension in the sides of the face to aid in showing stress or more often then not, a character will rub the temporalis to express quite contempt or exhaustion.
I would be remiss if I did not discuss the masseter (another chewing muscle but also the one that pulls the mandible back to the 'closed mouth' position. When relaxed as in sleep or after playing thirteen straight hours of WOW or Halo, this muscle is the one that lets the mouth dangle open so drool spill out copiously. When showing frustration or determination, the jaws will clench and flex-this is the muscle that employs that action.
The muscles of the face act as an orchestra that produce an entire concerto of emotions, some that last for fleeting moments and others that persist for a long time. Some expressions are strong, like anger or fear while others are subtle like pride or love. Take time to get to know and understand the actions of the face
Below are some examples of facial expression used in
"Me and My Feelings; What Emotions Are and How we Can manage Them" now available. Can you name the expressions and even better, list all of the muscles used in each?
Or...
I hope this helps! If you are interested in reading further about emotions check out these books:
Unmasking the Face and
Emotions Revealed both by
Paul Ekman. Now get out there and get some really expressive expressions! Thanks for stopping by.
On a different note, yet same topic; at least students of mine can't say I don't out of my way for them. For in class modeling on Thursdays, I opted to join them for 20 one minute poses...as Thor! (I have a hammer - - now) Thanks to Tien for the photos.
The above could almost work for for the Turnaround page (which is in need of some updating).
The stuff I do. Higher learning indeed. By the way, did I say I now have a crankin' hammer?
Let's go back to the skull, I have isolated the muscles and drawn what those specific muscles are doing. Refer to the labeled skull and labeled muscles images above to see where everything attaches etc. Here is an expressionless face that will be overlaid on the skull. In the images that follow, you will see this face (shown below) and on the left of the face, the muscle or muscle groups will be shown in action. Note, generally the muscles act as a group which also hides a specific muscle's action so the isolated versions may look out of context or even silly. 
Or...
