Anatomically, the neck is a complicated area. It supports the weight of your head and allows it to rotate and flex in different directions. But that’s not all it does.

The muscles in your neck assist with blood flow to the brain and protect motor neurons that deliver information from the brain to your body. Your neck muscles also help you:

  • breathe
  • swallow
  • eat

There are two types of neck muscles: superficial and deep.

Superficial muscles are closest to the skin and therefore most external. Deep neck muscles are closer to the bones and internal organs.

Understanding how these muscles work can help you figure out the cause of neck strain and how to treat it.

This article takes a closer look at the superficial and deep muscle groups of the neck, their function, and how they affect your daily movement patterns.

The superficial neck muscles are found on the sides of the neck closest to the surface. Pain and soreness are often experienced in these muscles. They consist of the:

Platysma muscle location

The platysma muscle starts in the upper chest and shoulders. It extends along the collarbone and the side of the neck, where it overlaps part of the sternocleidomastoid. Then it continues up into the lower jaw.

Sternocleidomastoid muscle location

The sternocleidomastoid muscle (SCM) starts at the base of your skull and runs along both sides of the neck. After the platysma, it’s the most superficial neck muscle and is also one of the biggest.

Trapezius muscle location

The trapezius is a thin, triangular muscle that extends across the upper back. It runs longitudinally from the occipital bone at the base of the skull to the lower thoracic vertebrae of the spine.

It extends laterally to the spine of the shoulder blades and attaches to the collarbone, ribs, and ligamentum nuchae muscle on the back of the neck.

The superficial neck muscles allow for both gross and fine motor movements of the head, face, and neck. They’re responsible for neck rotation and support the head so it can move in all directions.

Platysma muscle function

The platysma muscle lowers the lower jaw and allows you to:

  • open your mouth
  • move the corners of your lips to the side and down
  • tense the skin of lower face and neck

Moving the mouth and angling the mouth in this way makes it possible to make facial expressions such as:

  • surprise
  • fear
  • fright

Sternocleidomastoid muscle function

The sternocleidomastoid muscle protects some of the deeper structures, including the carotid artery and jugular vein.

It also rotates the head and allows for neck flexion. Plus, the SCM supports the head when you move it back and helps with chewing and swallowing.

Trapezius muscle function

The trapezius helps to keep the spine straight, which promotes good posture. It supports movement and stability in the shoulder blades.

It also helps with active movements, including:

  • head rotation
  • side bending
  • shrugging the shoulders

The trapezius:

  • creates neck extension
  • allows for outward movement of the arm
  • helps to throw objects

The deep muscles of the neck consist of the anterior and posterior triangles. These triangular areas are located deep in the skin and are divided by the sternocleidomastoid.

Each section contains several muscles. The deep neck muscles promote stability and movement of the head, neck, and spine. They work together with the superficial muscles to promote good posture and mobility.

Anterior triangle

The anterior triangle is located at the front of the neck and consists of four smaller triangles.

  • Submental. This triangle is found at the front of the neck right below the jaw. Its main muscle is the mylohyoid, which controls swallowing and shutting the mouth.
  • Submandibular. This triangle consists of the digastric muscle and is located deep under the jawbone.
  • Muscular-visceral. Located in the lower middle part of the neck, this triangle involves the sternohyoid, sternothyroid, and thyrothyroid muscles. These hold the thyroid cartilage, hyoid bone, and the larynx.
  • Carotid. This triangle is found on the sides of the neck. It contains the digastric, omohyoid, and sternocleidomastoid muscles, which flex the neck and jaw. They also anchor the hyoid bone, which helps to swallow and move the tongue.

Posterior triangle

The posterior triangle is situated behind the sternocleidomastoid muscle and is responsible for neck extension.

This large area of muscles stretches from behind the ear to the start of the shoulders along both sides of the neck. The anterior, middle, and posterior scalene muscles lift the first rib bone.

The posterior triangle also contains the levator scapulae and splenius capitis muscles.

These muscles extend from the back of the skull to the spine, creating a V-shape along the back of the neck. They stabilize and flex the head and assist in lifting up the shoulder blades.

The erector spinae start in the back of the neck and continue on either side of the spine into the pelvic region.

The erector spinae contain the iliocostalis, longissimus, and spinalis muscles, which assist with spinal stabilization and movement.

The superficial and deep neck muscles work together to allow for movement throughout your entire body.

Understanding the functions of these muscles may help you:

  • get to the root of neck pain
  • develop healthy movement patterns
  • heal existing neck injuries

Doing neck exercises regularly can help build strength and counteract any movements that cause pain or discomfort. You can also use: