Quick Facts
Origin: Nuchal ligament and spinous processes of C7-T2 vertebrae.
Insertion: Spinous processes of C2-C4 vertebrae.
Action: Extends and laterally flexes neck at cervical vertebral joints.
Innervation: Posterior rami of lower cervical and upper thoracic nerves.
Arterial Supply: Occipital, deep cervical, and vertebral arteries, dorsal branches of upper posterior intercostal arteries.
Related parts of the anatomy
Origin
The spinalis colli muscle originates from the:
- nuchal ligament;
- spinous processes of the seventh cervical to second thoracic vertebrae.
There can be variations between individuals regarding the origin sites for the spinalis colli muscle (Tubbs, Shoja and Loukas, 2016).
Insertion
The fibers of the spinalis colli muscle travel superiorly along the posterior neck region and insert onto the spinous processes of the axis (second cervical vertebra) to fourth cervical vertebrae. There can be variations between individuals regarding the insertion sites for the spinalis colli muscle (Tubbs, Shoja and Loukas, 2016).
Key Features & Anatomical Relations
Overall, the spinalis muscles are the most medial of the erector spinae. They are intrinsic muscles of the back and are found along the back and posterior neck regions. They are long, flat skeletal muscles that are composed of two parts:
- spinalis colli, which is the superior portion;
- spinalis thoracis, which is the inferior portion.
In some individuals, there is a third part, known as the spinalis capitis, which, blends with the semispinalis capitis muscle (Greiner, Bedford and Walker, 2004).
The spinalis muscles are located:
- superficial to the semispinalis and multifidus muscles;
- deep to the splenius capitis, splenius colli, trapezius, latissimus dorsi, and serratus posterior inferior muscles, and the thoracolumbar fascia;
- medial to the longissimus muscle.
Actions
The spinalis colli muscle is involved in multiple actions:
- during unilateral contraction, it laterally flexes the neck to the same side at the cervical vertebral joints;
- during bilateral contraction, it extends the neck at the cervical vertebral joints (Moore, Dalley and Agur, 2009).
References
Greiner, T. M., Bedford, M. E. and Walker, R. A. (2004) 'Variability in the human M. spinalis capitis and cervicis: frequencies and definitions', Annals of Anatomy - Anatomischer Anzeiger, 186(2), pp. 185-191.
Moore, K. L., Dalley, A. F. and Agur, A. M. R. (2009) Clinically Oriented Anatomy. Lippincott Williams & Wilkins.
Tubbs, R. S., Shoja, M. M. and Loukas, M. (2016) Bergman's Comprehensive Encyclopedia of Human Anatomic Variation. Wiley.
