C7 Nerve root

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

Level	Root	Pain & Sensory Change	Motor Weakness	Abnormal Reflexes
C4/C5	C5	Deltoid1 Lateral arm1	Deltoid1 Biceps1	Bicep reflex1
C5/C6	C6	Radial forearm to thumb and index finger1	Biceps1 Wrist extensor1	Bicep reflex1 Brachioradialis reflex1
C6/C7	C7	Midradial forearm to index and middle finger1	Wrist Flexor1 Tricep1	Triceps reflex1
C7/T1	C8	Ulnar forearm to ring and little finger1	Hand Intrinsic1 Finger Flexor1	N/a1

Motor Innervation

C7 Nerve Root Skeletal Muscle Innervations
Muscle	Origin	Insertion	Innervation	Action
Coracobrachialis	Coracoid process2 [Coracoid process](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Arm Anterior Muscles/coracobrachialis.html#origin) [@gilroyAtlasAnatomy2020]	Humerus (in line with crest of lesser tubercle)2 [Humerus (in line with crest of lesser tubercle)](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Arm Anterior Muscles/coracobrachialis.html#insertion) [@gilroyAtlasAnatomy2020]	Musculocutaneous n.2 C5 - C72 [Musculocutaneous n.](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Arm Anterior Muscles/coracobrachialis.html#nerve) [@gilroyAtlasAnatomy2020] [C5](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Arm Anterior Muscles/coracobrachialis.html#nerve) - [C7](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Arm Anterior Muscles/coracobrachialis.html#nerve) [@gilroyAtlasAnatomy2020]	GHJ [Flexion](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Arm Anterior Muscles/coracobrachialis.html#action) [@gilroyAtlasAnatomy2020] [Adduction](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Arm Anterior Muscles/coracobrachialis.html#action) [@gilroyAtlasAnatomy2020] [IR](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Arm Anterior Muscles/coracobrachialis.html#action) [@gilroyAtlasAnatomy2020]
Middle scalene	C1-C2 TP2 Posterior tubercle of TP of C3-C72 C1-C2 TP [@gilroyAtlasAnatomy2020] Posterior tubercle of TP of C3-C7 [@gilroyAtlasAnatomy2020]	1st Rib (posterior to groove for subclavian a.)2 1st Rib (posterior to groove for subclavian a.) [@gilroyAtlasAnatomy2020]	Anterior Rami2 C3 - C82 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]
Pectoralis major	Clavicle (medial half)2 Sternum2 Costal cartilages 1-62 Rectus sheath (anterior layer)2 [Clavicle (medial half)](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/pectoralis_major_muscle.html#origin) [@gilroyAtlasAnatomy2020] [Sternum](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/pectoralis_major_muscle.html#origin) [@gilroyAtlasAnatomy2020] [Costal cartilages 1-6](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/pectoralis_major_muscle.html#origin) [@gilroyAtlasAnatomy2020] [Rectus sheath (anterior layer)](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/pectoralis_major_muscle.html#origin) [@gilroyAtlasAnatomy2020]	Humerus (crest of greater tubercle)2 [Humerus (crest of greater tubercle)](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/pectoralis_major_muscle.html#insertion) [@gilroyAtlasAnatomy2020]	Lateral pectoral n.2 Medial pectoral n.2 C5 - T12 [Lateral pectoral n.](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/pectoralis_major_muscle.html#nerve) [@gilroyAtlasAnatomy2020] [Medial pectoral n.](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/pectoralis_major_muscle.html#nerve) [@gilroyAtlasAnatomy2020] [C5](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/pectoralis_major_muscle.html#nerve) - [T1](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/pectoralis_major_muscle.html#nerve) [@gilroyAtlasAnatomy2020]	Clavicular & Sternocostal parts [Flexion](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/pectoralis_major_muscle.html#action) [@gilroyAtlasAnatomy2020] [Aids in respiration when shoulder is fixed](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/pectoralis_major_muscle.html#action) [@gilroyAtlasAnatomy2020] Entire muscle [Adduction](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/pectoralis_major_muscle.html#action) [@gilroyAtlasAnatomy2020] [IR](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/pectoralis_major_muscle.html#action) [@gilroyAtlasAnatomy2020]
Posterior scalene	Posterior tubercle of TP of C5-C72 Posterior tubercle of TP of C5-C7 [@gilroyAtlasAnatomy2020]	2nd Rib (outer surface)2 2nd Rib (outer surface) [@gilroyAtlasAnatomy2020]	Anterior Rami2 C6 - C82 Anterior Rami [@gilroyAtlasAnatomy2020] C6 - 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]
Serratus anterior	1-9 Ribs2 [1-9 Ribs](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/serratus_anterior_muscle.html#origin) [@gilroyAtlasAnatomy2020]	Superior angle of Scapula (costal and dorsal surfaces)2 Medial border of scapula (costal surface)2 Medial border of scapula (costal surface)2 Inferior angle of Scapula (costal & dorsal surfaces)2 [Superior angle of Scapula (costal and dorsal surfaces)](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/serratus_anterior_muscle.html#insertion) [@gilroyAtlasAnatomy2020] [Medial border of scapula (costal surface)](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/serratus_anterior_muscle.html#insertion) [@gilroyAtlasAnatomy2020] [Medial border of scapula (costal surface)](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/serratus_anterior_muscle.html#insertion) [@gilroyAtlasAnatomy2020] [Inferior angle of Scapula (costal & dorsal surfaces)](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/serratus_anterior_muscle.html#insertion) [@gilroyAtlasAnatomy2020]	Long thoracic n.2 C5 - C72 [Long thoracic n.](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/serratus_anterior_muscle.html#nerve) [@gilroyAtlasAnatomy2020] [C5](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/serratus_anterior_muscle.html#nerve) - [C7](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/serratus_anterior_muscle.html#nerve) [@gilroyAtlasAnatomy2020]	Entire mm. [Protraction](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/serratus_anterior_muscle.html#action) [@gilroyAtlasAnatomy2020] [Rib elevation (with fixed shoulder)](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/serratus_anterior_muscle.html#action) [@gilroyAtlasAnatomy2020] Inferior part [Rotates scapula laterally forward](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/serratus_anterior_muscle.html#action) [@gilroyAtlasAnatomy2020] Superior part [Lowers raised arm](/The Archive/Anatomy/Skeletal Muscles/Upper Limb Muscles/Axioappendicular Anterior Muscles/serratus_anterior_muscle.html#action) [@gilroyAtlasAnatomy2020]

Lesion

“This nerve root is often compressed by disc herniation at the C6 C7 vertebral level (the most common level of disc herniation) [20,29]. C7 root involvement results in pain in the dorsal forearm. In some patients, pain may be subscapular or located in the deep breast or chest [24]. Sensory disturbances occur on the third and fourth digits. Paresis occurs variably in the following muscles: serratus anterior, pectoralis major, latissimus dorsi, pronator teres, flexor carpi radialis, triceps, extensor carpi radialis longus, extensor carpi radialis brevis, and extensor digitorum (examination of these muscles is described in Chapter 2 ). The triceps reflex (C7 C8) may be depressed.”³

“Pseudomyotonia is a term applied to the difficulty in opening the hand because of cervical osteoarthritis. Muscle relaxation is normal but attempts to extend the fingers produce paradoxical flexion of the fingers, probably as a result of misdirected regeneration of C7 nerve root fibers [34].”³

Examination

Muscle Strength

“The clinician asks the patient to place the arms out in front, with the elbows flexed slightly and the forearms, wrists, and fingers in neutral. The clinician applies an upward force to the palm of the patient’s hands (Fig. 25-28).”⁴

References

1.

Hong CG, Nam WD. Reliability and Diagnostic Accuracy of Standard Dermatomes and Myotomes for Determining the Pathologic Level in Surgically Verified Patients With Cervical Radiculopathy. Neurospine. 2022;19(4):1006-1012. doi:10.14245/ns.2244194.097

2.

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

3.

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

4.

Dutton M. Dutton’s Orthopaedic Examination, Evaluation, and Intervention. 5th ed. McGraw Hill Education; 2020.