C4 Nerve Root (C4)

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

C4 Nerve Root Skeletal Muscle Innervations
Muscle	Origin	Insertion	Innervation	Action
Anterior scalene	Anterior tubercle of TP of C3-C61 Anterior tubercle of TP of C3-C6 [@gilroyAtlasAnatomy2020]	Scalene tubercle of 1st Rib1 Scalene tubercle of 1st Rib [@gilroyAtlasAnatomy2020]	Anterior Rami1 C4 - C61 Anterior Rami [@gilroyAtlasAnatomy2020] C4 - C6 [@gilroyAtlasAnatomy2020]	Fixed ribs (bil) C/s flexion [@gilroyAtlasAnatomy2020] Cervical lateral stabilization [@finandoTriggerPointTherapy2005] Fixed ribs (unilateral) I/L C/s sidebend (unilateral) [@gilroyAtlasAnatomy2020] Mobile ribs Elevates ribs during forced inspiration [@gilroyAtlasAnatomy2020]
Lower trapezius	T5-T12 SP1 [T5-T12 SP](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/lower_trapezius.html#origin) [@gilroyAtlasAnatomy2020]	Scapular spine1 [Scapular spine](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/lower_trapezius.html#insertion) [@gilroyAtlasAnatomy2020]	Accessory n. (CN XI)1 C3 - C41 [Accessory n. (CN XI)](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/lower_trapezius.html#nerve) [@gilroyAtlasAnatomy2020] [C3](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/lower_trapezius.html#nerve) - [C4](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/lower_trapezius.html#nerve) [@gilroyAtlasAnatomy2020]	Scapula [Retraction](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/lower_trapezius.html#action) [@gilroyAtlasAnatomy2020] [Depression](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/lower_trapezius.html#action) [@gilroyAtlasAnatomy2020] [Upward rotation](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/lower_trapezius.html#action) [@neumannKinesiologyMusculoskeletalSystem2017] [Stabilizes scapula on thorax](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/lower_trapezius.html#action) [@gilroyAtlasAnatomy2020]
Middle scalene	C1-C2 TP1 Posterior tubercle of TP of C3-C71 C1-C2 TP [@gilroyAtlasAnatomy2020] Posterior tubercle of TP of C3-C7 [@gilroyAtlasAnatomy2020]	1st Rib (posterior to groove for subclavian a.)1 1st Rib (posterior to groove for subclavian a.) [@gilroyAtlasAnatomy2020]	Anterior Rami1 C3 - C81 Anterior Rami [@gilroyAtlasAnatomy2020] C3 - C8 [@gilroyAtlasAnatomy2020]	Fixed ribs (bil) C/s flexion [@gilroyAtlasAnatomy2020] Cervical lateral stabilization [@finandoTriggerPointTherapy2005] Fixed ribs (unilateral) I/L C/s sidebend (unilateral) [@gilroyAtlasAnatomy2020] Mobile ribs Elevates ribs during forced inspiration [@gilroyAtlasAnatomy2020]
Middle trapezius	Aponeurosis of T1-T4 SP1 [Aponeurosis of T1-T4 SP](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/middle_trapezius.html#origin) [@gilroyAtlasAnatomy2020]	Acromion1 [Acromion](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/middle_trapezius.html#insertion) [@gilroyAtlasAnatomy2020]	Accessory n. (CN XI)1 C3 - C41 [Accessory n. (CN XI)](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/middle_trapezius.html#nerve) [@gilroyAtlasAnatomy2020] [C3](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/middle_trapezius.html#nerve) - [C4](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/middle_trapezius.html#nerve) [@gilroyAtlasAnatomy2020]	Scapula [Retraction](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/middle_trapezius.html#action) [@gilroyAtlasAnatomy2020]
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]
Supraspinatus	Supraspinous Fossa of scapula1 [Supraspinous Fossa of scapula](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Intrinsic Shoulder Muscles/Rotator Cuff/supraspinatus_muscle.qmd#origin) [@gilroyAtlasAnatomy2020]	Greater tubercle of Humerus1 [Greater tubercle of Humerus](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Intrinsic Shoulder Muscles/Rotator Cuff/supraspinatus_muscle.qmd#insertion) [@gilroyAtlasAnatomy2020]	Suprascapular n. (C4, C5, C6)1 C4 - C61 [Suprascapular n. (C4, C5, C6)](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Intrinsic Shoulder Muscles/Rotator Cuff/supraspinatus_muscle.qmd#nerve) [@gilroyAtlasAnatomy2020] [C4](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Intrinsic Shoulder Muscles/Rotator Cuff/supraspinatus_muscle.qmd#nerve) - [C6](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Intrinsic Shoulder Muscles/Rotator Cuff/supraspinatus_muscle.qmd#nerve) [@gilroyAtlasAnatomy2020]	Stabilization1 GHJ ER1 [Stabilization](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Intrinsic Shoulder Muscles/Rotator Cuff/supraspinatus_muscle.qmd#action) [@gilroyAtlasAnatomy2020] GHJ [ER](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Intrinsic Shoulder Muscles/Rotator Cuff/supraspinatus_muscle.qmd#action) [@gilroyAtlasAnatomy2020]
Upper trapezius	Occiput1 SP C1-C71 [Occiput](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/upper_trapezius_muscle.html#origin) [@gilroyAtlasAnatomy2020] [SP C1-C7](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/upper_trapezius_muscle.html#origin) [@gilroyAtlasAnatomy2020]	lateral ⅓ of Clavicle1 [lateral ⅓ of Clavicle](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/upper_trapezius_muscle.html#insertion) [@gilroyAtlasAnatomy2020]	Accessory n. (CN XI)1 C3 - C41 [Accessory n. (CN XI)](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/upper_trapezius_muscle.html#nerve) [@gilroyAtlasAnatomy2020] [C3](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/upper_trapezius_muscle.html#nerve) - [C4](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/upper_trapezius_muscle.html#nerve) [@gilroyAtlasAnatomy2020]	Neck [I/L sidebend](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/upper_trapezius_muscle.html#action) [@gilroyAtlasAnatomy2020] [C/L Rotation](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/upper_trapezius_muscle.html#action) [@gilroyAtlasAnatomy2020] Scapula [Elevation](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/upper_trapezius_muscle.html#action) [@gilroyAtlasAnatomy2020] [Upward rotatino](/The Archive/Anatomy/Skeletal Muscles/Head and Neck/Neck Muscles/upper_trapezius_muscle.html#action) [@gilroyAtlasAnatomy2020]

Lesion

“Sensory signs and symptoms occur on the lower neck. Paresis occurs in the scalene and levator scapulae muscles (lateral neck flexion and scapular rotation, respectively), rhomboid muscles (scapular elevation and adduction), trapezius muscle (shoulder elevation), and some muscles of the neck. Diaphragmatic paresis may also occur because some fibers reach the phrenic nerve. There is no reflex impairment.”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.