Muscles are named according to their shape, location, or a combination. They are further categorized according function such as flexion, extension, or rotation. Muscles and ligaments work together to support the spine, hold it upright, and control movement during rest and activity.
| Forward flexors | Anterior |
| Lateral flexors | Lateral |
| Rotators | Lateral |
| Extensors | Posterior |
Skeletal muscle is striated (striped) in appearance. It is innervated, under voluntary control, and has the fastest contraction rate of all muscle. Prior to a muscle contracting, a nerve impulse originates in the brain and travels through the spinal cord to the muscle.
Energy is needed for the muscle to contract (work). Mitochondria (cellular level) produce ATP (adenosine triphosphate), a chemical cells need for energy. ATP is produced as the mitochondria burn glucose (sugar). Blood vessels deliver the oxygen and nutrients the mitochondria needs to provide a steady supply of ATP.
Muscles of the Posterior Cervical and Upper Thoracic Spine
Semispinalis Capitus (head rotation/pulls backward)
Iliocostalis Cervicis (extends cervical vertebrae)
Longissimus Cervicus (extends cervical vertebrae)
Longissimus Capitus (head rotation/pulls backward)
Longissimus Thoracis (extension/lateral flexion vertebral column, rib rotation)
Iliocostalis Thoracis (extension/lateral flexion vertebral column, rib rotation)
Semispinalis Thoracis (extends/rotates vertebral column)
Muscles of the Spinal Column
| Sternocleidomastoid | Extends & rotates head, flexes vertebral column | C2, C3 |
| Scalenus | Flexes & rotates neck | Lower cervical |
| Spinalis Cervicis | Extends & rotates head | Middle/lower cervical |
| Spinalis Capitus | Extends & rotates head | Middle/lower cervical |
| Semispinalis Cervicis | Extends & rotates vertebral column | Middle/lower cervical |
| Semispinalis Capitus | Rotates head & pulls backward | C1 – C5 |
| Splenius Cervicis | Extends vertebral column | Middle/lower cervical |
| Longus Colli Cervicis | Flexes cervical vertebrae | C2 – C7 |
| Longus Capitus | Flexes head | C1 – C3 |
| Rectus Capitus Anterior | Flexes head | C2, C3 |
| Rectus Capitus Lateralis | Bends head laterally | C2, C3 |
| Iliocostalis Cervicis | Extends cervical vertebrae | Middle/lower cervical |
| Longissimus Cervicis | Extends cervical vertebrae | Middle/lower cervical |
| Longissimus Capitis | Rotates head & pulls backward | Middle/lower cervical |
| Rectus Capitus Posterior Major | Extends & rotates head | Suboccipital |
| Rectus Capitus Posterior Minor | Extends head | Suboccipital |
| Obliquus Capitus Inferior | Rotates atlas | Suboccipital |
| Obliquus Capitus Superior | Extends & bends head laterally | Suboccipital |
| Longissimus Thoracis | Extension, lateral flexion of vertebral column, rib rotation | Dorsal primary divisions of spinal nerves |
| Iliocostalis Thoracis | Extension, lateral flexion of vertebral column, rib rotation | Dorsal primary divisions of spinal nerves |
| Spinalis Thoracis | Extends vertebral column | Dorsal primary divisions of spinal nerves |
| Semispinalis Thoracis | Extends & rotates vertebral column | Dorsal primary divisions of spinal nerves |
| Rotatores Thoracis | Extends & rotates vertebral column | Dorsal primary divisions of spinal nerves |
| Psoas Major | Flexes thigh at hip joint & vertebral column | L2, L3, sometimes L1 or L4 |
| Intertransversarii Lateralis | Lateral flexion of vertebral column | Ventral primary division of spinal nerves |
| Quadratus Lumborum | Lateral flexion of vertebral column | T12, L1 |
| Interspinales | Extends vertebral column | Dorsal primary divisions of spinal nerves |
| Intertransversarii Mediales | Lateral flexion of vertebral column | Dorsal primary divisions of spinal nerves |
| Multifidus | Extends & rotates vertebral column | Dorsal primary divisions of spinal nerves |
| Longissimus Lumborum | Extends & rotates vertebral column | Dorsal primary divisions of spinal nerves |
| Iliocostalis Lumborum | Extension, lateral flexion of vertebral column, rib rotation | Dorsal primary divisions of spinal nerves |
Muscle Fascia
Fascia is thickened connective tissue that envelops a muscle or a group of muscles. Superficial fascia is found directly under the skin. Epimysium is the fascia closest to the muscle. Perimysium divides the muscle into facicles – muscle fibers. Endomysium is another type of connective tissue that covers each muscle fiber.
Notes: This article was originally published June 7, 2001 and most recently updated May 15, 2019.
Watch Cervical Muscle Anatomy Animation
Neck muscles help support the cervical spine and contribute to movements of the head, neck, upper back, and shoulders. Here are some of the key muscles attached to the cervical spine:
- Levator scapulae. The levator scapulae muscle is attached at the top four cervical vertebrae (C1 to C4) and runs down the side of the neck to attach at the top of the shoulder blade (scapula). This muscle helps with lifting the shoulder blade, bending the neck to the side, and rotating the head.
See Easy Levator Scapulae Stretch for Neck Pain
- Sternocleidomastoid (SCM). The SCM muscle is attached to a small bone behind the ear (called the mastoid process) and travels down the front of the neck to attach at both the sternum and collarbone. Depending on whether one or both SCM muscles (one on each side of the neck) are contracted, the head can be rotated to the side or the chin tilted upward. It is a large muscle that also helps protect some fragile structures, such as the carotid artery.
- Trapezius. The trapezius muscle is a large surface muscle that spans from the base of the skull down the cervical spine and into the lower thoracic spine (mid back), as well as out to the shoulder blade. The two trapezius muscles together form a kite shape. The trapezius muscle can be involved in extending the head upward or neck backward, rotating/turning the head, or lifting the shoulder blade.
See Thoracic Spine Anatomy and Upper Back Pain
- Erector spinae. Numerous muscles comprise the erector spinae muscles throughout the spine. In the cervical spine, the erector spinae muscles play key roles in supporting posture, rotating the neck, and extending the neck backward.
- Deep cervical flexors. The muscle group is comprised of the longus capitus and longus colli muscles, which run down the front of the cervical spine. The deep cervical flexor muscles are involved in flexing the neck forward as well as stabilizing the cervical spine.
- Suboccipitals. Comprised of 4 pairs of small muscles, the suboccipital muscles connect the top of the cervical spine with the base of the skull. The suboccipitals are important for head extension and rotation.
See Forward Head Posture’s Effect on Neck Muscles
There are numerous other muscles connected to the neck, which all work in concert with tendons (connect muscles to bones) and ligaments (connect bones to bones). If a neck muscle is strained, it can become painful, tight, and possibly lead to a stiff neck.
See Stiff Neck Causes, Symptoms, and Treatment
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Ligaments are durable soft tissues that connect bones together. There are many ligaments in the neck, but 3 types are important for helping to stabilize the entire spine:
- Anterior longitudinal ligament (ALL). This ligament starts at the base of the skull (occiput) and goes down the front of the vertebral bodies and intervertebral discs. When the neck is extended backwards, the ALL is the key ligament to resist and become stretched during that movement.
- Posterior longitudinal ligament (PLL). The PLL starts at C2 and goes down the back of the vertebral bodies and intervertebral discs. When the neck is flexed forward, this ligament stretches and resists that motion. The PLL is located inside the spinal canal in front of the spinal cord.
- Ligamentum flava. The ligamentum flava are short, paired ligaments that connect the vertebral arches of adjacent vertebrae, helping to cover the spinal cord from behind. Starting at C2-C3, each ligamentum flavum connects a lamina to the lamina below. Over time, the ligament flava thicken and in some cases contribute to compressing a spinal nerve root or the spinal cord.
The ligamentum flava are a pair of ligaments that connect the laminae (bony vertebral arches) of adjacent vertebrae at the back wall of the spinal canal.
There are numerous other ligaments that play a part in holding neck bones together, which is crucial for other neck functions to occur, such as facilitating blood flow through the cervical spine.
Blood Supply of the Cervical Spine
The vertebral artery is critical to supplying blood from the heart to the brain and spinal cord. A right and left vertebral artery travel up the cervical spine symmetrically. The vertebral artery typically follows this general path:
- Branches from the subclavian artery above the heart and goes into a bony hole (foramen) in C6’s transverse process.
See All About the C5-C6 Spinal Motion Segment
- Travels straight up the cervical spine through the foramina from C6 to C2.
- Takes more of a winding route when traveling from C2 (axis) to and through the foramen of C1 (atlas).
See The C1-C2 Vertebrae and Spinal Segment
- Travels from C1 and goes beneath the posterior atlanto-occipital membrane (which stretches from the top of C1 to the base of the skull) to enter the spinal cord.
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Once inside the spinal cord, the right and left vertebral arteries join in the basilar artery to supply the brainstem. There are also many arteries that branch off the various levels of the vertebral arteries to send blood to the spinal cord, bones, joints, and other areas.
If a vertebral artery starts to become compressed due to spinal degeneration or injury, it can cause neck pain, headache, and/or possibly dizziness.