Muscle guide · Neck

Sternocleidomastoid

Also called SCM, front of the neck muscle

The sternocleidomastoid is the rope-like muscle you can see on each side of the neck, running diagonally from the top of the breastbone and the inner collarbone up to the bony bump behind the ear.

One side turns the head to the opposite side and tilts it toward the same side; both together bend the neck forward, as when you lift your head off a pillow, and help lift the chest in a deep breath.

4 exercises 2 stretches6 with 3D demos4 sourcesUpdated 17 October 2026

Where the sternocleidomastoid is and what it does

Starts at (origin): The top of the breastbone and the inner end of the collarbone (two heads).Manubrium of the sternum (sternal head); medial clavicle (clavicular head)
Attaches to (insertion): The bony bump behind the ear and the adjoining base of the skull.Mastoid process and lateral superior nuchal line
What it does: One side turns the head the other way and tilts it to its own side: looking over your left shoulder uses the right SCM.Contralateral rotation and ipsilateral side-bending
Both sides bend the neck forward: lifting your head off the pillow.Bilateral neck flexion
Helps lift the chest for a deep breath.Accessory inspiration
Nerve supply: Accessory nerve (cranial nerve XI), with position-sense fibres from the cervical plexus.

Source 1

Exercises for the sternocleidomastoid

In a year-long trial in women with chronic neck pain, neck strength training with an elastic band cut pain and disability and more than doubled neck flexion strength. It trained the neck muscles together; no study isolated the SCM.

Chin tuck with head lift demonstrated on the 3D figure

3D demoChin tuck with head liftIntermediate · No equipment

Isometric neck holds (four-way) demonstrated on the 3D figure

3D demoIsometric neck holds (four-way)Beginner · No equipment

Isometric Neck Exercise - Sides demonstrated on the 3D figure

3D demoIsometric Neck Exercise - SidesBeginner · No equipment

Lying chin tuck demonstrated on the 3D figure

3D demoLying chin tuckBeginner · No equipment

Neck exercises6

Stretches for the sternocleidomastoid

Tilt the head away and turn it slightly back toward the side being stretched.

Side Neck Stretch demonstrated on the 3D figure

3D demoSide Neck StretchBeginner · Other / check instructions

3D demoChin tuckBeginner · No equipment

Neck stretches19

Problems linked to the sternocleidomastoid

Wry neck (torticollis)

A tight or shortened SCM pulls the head into a tilt with the chin turned away. In babies it is usually congenital and treated with stretching physiotherapy; in adults it can come from nerve injury or a dystonia.

Source 1

Chronic neck painEmerging evidence

People with chronic neck pain tend to use the SCM more, and the deep neck flexors less, when they bend the neck. Strength training of the neck muscles helps, and stretching and massage add benefit when combined with physiotherapy.

Sources 1, 3, 4

Routines that train it

Neck and shoulder stretches

Eight gentle neck and shoulder stretches for desk stiffness, done standing or seated in ten minutes.

10 minBeginner8 movesA wall

5-minute desk stretches

A quick stretch break you can do beside your desk: neck, back, chest, wrists, hips and quads.

5 minBeginner7 movesA wall

Questions people ask

What does the sternocleidomastoid do?

One side turns the head the opposite way and tilts it to the same side; both together bend the neck forward and help with deep breaths.

How do you stretch the SCM?

Tilt your head away from the side you want to stretch and turn it slightly back toward that side.

Can the SCM cause neck pain?

People with chronic neck pain tend to overuse it; strengthening the neck muscles helped neck pain in a long-term trial.

Muscles it works with

Sources

Anatomy and movement education, not a diagnosis or treatment plan. If you have pain that follows an injury, is severe or getting worse, or comes with numbness, weakness or swelling, get it assessed. Health disclaimer.