Frontalis

Origin, Insertion, Action & Nerve

Attachments explained

The Frontalis is defined first by where it attaches. Its origin is the more fixed anchor, usually the proximal or more stable end that stays put during contraction, while its insertion is the more mobile point that is pulled toward the origin when the muscle shortens.

Action & function

When the Frontalis contracts, it produces the following movements: Elevates the eyebrows and wrinkles the forehead (transverse creases); draws the scalp anteriorly.

As part of the Facial Expression group of the Head & Neck, it works alongside neighbouring muscles to generate smooth, coordinated movement and to stabilise the structures it acts on.

Nerve supply & clinical relevance

The Frontalis receives its nerve supply from the Temporal branch of facial nerve (CN VII).

Because a muscle can only contract when its nerve is intact, injury to the Temporal branch of facial nerve can weaken or paralyse the Frontalis, impairing the movements it normally produces (elevates the eyebrows and wrinkles the forehead (transverse creases)). This is why knowing the innervation is central to localising nerve lesions in clinical practice.

How to study the Frontalis (the OIANS method)

OIANS stands for Origin, Insertion, Action and Nerve, the four facts that uniquely define every skeletal muscle. To learn the Frontalis, work through them in order: picture its origin, trace the muscle to its insertion, reason out the action that shortening between those two points must create, then add the nerve that drives it.

Most students remember the Frontalis fastest by linking its action back to its attachments rather than memorising each fact in isolation. Once the origin and insertion make sense, the action usually follows logically.

Frontalis quick facts

Region

Head & Neck

Group

Facial Expression

Origin

Epicranial aponeurosis (galea aponeurotica)

Insertion

Skin and subcutaneous tissue of the eyebrows and glabella

Action

Elevates the eyebrows and wrinkles the forehead (transverse creases); draws the scalp anteriorly

Nerve

Temporal branch of facial nerve (CN VII)

Spinal roots

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Frequently asked questions

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