C2 Nerve Root (C2)

Authors

Affiliations

Nathaniel Yomogida, B.S., SPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, B.S., SPT

Doctor of Physical Therapy

B.A. in Neuroscience

Motor Innervation

C2 Nerve Root Skeletal Muscle Innervations
Muscle	Origin	Insertion	Innervation	Action
Splenius capitis	Nuchal lig.1 C7-T4 SP1 Nuchal lig. [@gilroyAtlasAnatomy2020] C7-T4 SP [@gilroyAtlasAnatomy2020]	Lateral third of nuchal line1 Mastoid process1 Lateral third of nuchal line [@gilroyAtlasAnatomy2020] Mastoid process [@gilroyAtlasAnatomy2020]	Spinal nn.1 Posterior rami (lateral br.)1 C1 - C61 Spinal nn. [@gilroyAtlasAnatomy2020] Posterior rami (lateral br.) [@gilroyAtlasAnatomy2020] C1 - C6 [@gilroyAtlasAnatomy2020]	Bilateral Head and neck extension [@gilroyAtlasAnatomy2020] Unilateral I/L sidebend [@gilroyAtlasAnatomy2020] I/L rotation [@gilroyAtlasAnatomy2020]
Splenius cervicis	T3-T7 SP1 T3-T7 SP [@gilroyAtlasAnatomy2020]	C1-C4 SP1 C1-C4 SP [@gilroyAtlasAnatomy2020]	Spinal nn.1 Posterior rami (lateral br.)1 C1 - C61 Spinal nn. [@gilroyAtlasAnatomy2020] Posterior rami (lateral br.) [@gilroyAtlasAnatomy2020] C1 - C6 [@gilroyAtlasAnatomy2020]	Bilateral Head and neck extension [@gilroyAtlasAnatomy2020] Unilateral I/L sidebend [@gilroyAtlasAnatomy2020] I/L rotation [@gilroyAtlasAnatomy2020]
Sternocleidomastoid	Manubrium1 Medial third of Clavicle1 Manubrium [@gilroyAtlasAnatomy2020] Medial third of Clavicle [@gilroyAtlasAnatomy2020]	Mastoid process1 Superior nuchal line1 Mastoid process [@gilroyAtlasAnatomy2020] Superior nuchal line [@gilroyAtlasAnatomy2020]	CN XI Accessory n.1 Cervical plexus1 C2 - C41 CN XI Accessory n. [@gilroyAtlasAnatomy2020] Cervical plexus [@gilroyAtlasAnatomy2020] C2 - C4 [@gilroyAtlasAnatomy2020]	SCJ stabilization NA Bilateral Head extension1 Cervical Flexion2 Assists in respiration1 Prevents posterior translation during mastication2 Unilateral I/L cervical sidebend1 C/L cervical rotation1 SCJ stabilization NA Bilateral Head extension [@gilroyAtlasAnatomy2020] Cervical Flexion [@finandoTriggerPointTherapy2005] Assists in respiration [@gilroyAtlasAnatomy2020] Prevents posterior translation during mastication [@finandoTriggerPointTherapy2005] Unilateral I/L cervical sidebend [@gilroyAtlasAnatomy2020] C/L cervical rotation [@gilroyAtlasAnatomy2020]

Lesion

“Sensory symptoms and signs due to C2 lesions are localized to the scalp posterior to the interaural line (the C2 dermatome). The motor supply of this segment involves the same muscles responsible for head and neck movements as those innervated by segment C1. In addition, the C2 nerve helps supply the sternocleidomastoid muscle (head rotation and flexion)

which is predominantly innervated by the spinal accessory nerve (cranial nerve XI).”³

References

1.

Gilroy AM, MacPherson BR, Wikenheiser JC, Voll MM, Wesker K, Schünke M, eds. Atlas of Anatomy. 4th ed. Thieme; 2020.

2.

Finando D, Finando SJ, Finando D. Trigger Point Therapy for Myofascial Pain: The Practice of Informed Touch. Healing Arts Press; 2005.

3.

Brazis PW, Masdeu JC, Biller J. Localization in Clinical Neurology. 8th ed. Wolters Kluwer Health; 2022.