Learn Muscle Anatomy: Occipitofrontalis
Have you ever made faces at yourself in the mirror? What am I talking about, of course you have (when you're brushing your teeth, watch the hilarious things your eyebrows do).
Many of the expressive things we do with our face are thanks to the facial muscles of expression. If you've a mirror handy, take a look in it and furrow your forehead or lift your eyebrows. One of the largest of the expression muscles is responsible for those faces you're making: the occipitofrontalis.
Image from Human Anatomy Atlas.
The occipitofrontalis is an interesting muscle. It is comprised of three sections: the frontalis, the occipitalis, and the galea aponeurotica. Each section is responsible for a different action involving the scalp, forehead, or brows.
Let's take a look, shall we?
Frontalis Muscle
The frontalis muscle is a thin, flat band in the anterior scalp. It has several origin points: the procerus muscle, the corrugator supercilii muscle, the orbicularis oculi fascia, and the zygomatic process of the frontal bone. It obviously covers a lot of ground. It inserts on the superficial fascia of the facial muscles, as well as the skin above the nose and eyes.
Image from Human Anatomy Atlas.
The frontalis muscle is at work when the scalp is drawn anteriorly—for example, when you lift your eyebrows, which also lifts the skin above your eyes and nose. Press your fingers to the bridge of your nose and waggle your eyebrows; feel how the muscle pulls at the skin?
Occipitalis Muscle
The occipitalis is a thin quadrilateral muscle in the posterior scalp. It originates on the occipital bone and the mastoid process of the temporal bone. It inserts into the galea aponeurotica.
The occipitalis draws the scalp posteriorly.
Image from Human Anatomy Atlas.
Galea Aponeurotica
The galea aponeurotica (which is hella fun to say) is a broad, fibrous sheet covering the upper part of the cranium. It originates on the occipital bone and inserts into both the occipitalis and frontalis muscles.
Image from Human Anatomy Atlas.
The aponeurosis helps with scalp movement.
Occipitofrontalis Pain
Pain in the occipitofrontalis is usually found in either the frontalis or the occipitalis. In the frontalis, the pain is usually in the forehead; in the occipitalis, there can be moderate pain at the back of the skull, which sometimes refers to the suboccipital and causes severe pain at the back of the eye. This can sometimes lead one to believe they are having a stroke (yikes!).
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Additional Sources:
- American Academy of Manual Medicine
- NBCI
