 Roots  C5  C6  C7  C8  T1  Trunks  Upper 5,6  Middle 7  Lower 8,1  Divisions  Anterior – primarily flexors  Posterior – primarily extensors  Cords  Lateral C5,6,7  Posterior C5,6,7,8  Medial C8,T1

 1 st cervical nerve exits ABOVE C1 vertebra  2 nd through 7 th nerves exit above corresponding vertebrae  8 th cervical nerve exits BELOW C7 vertebra Note: There are 7 cervical vertebrae There are 8 cervical nerves

 Defined: The defined segmental portion of the skin innervated by the sensory component of each spinal nerve.  Sensory testing helps localize the level of the nerve root lesion Note: Territories of dermatomes do overlap

 C5  C6  C7  C8  T1

 Spinal Cord Segments  C5, C6, C7  Muscles Innervated  Serratus

 Spinal Cord Segment  C5 (C4 is variable)  Muscles Innervated  Levator  Rhomboids

 Spinal Cord Segments  C5, C6  Muscles Innervated  SC

 Spinal Cord Segments  C4, C5, C6  Muscles Innervated  SS  IS

 Innervates volar aspect of U.E.  Spinal Cord Segments  C5  C6  C7  C8  T1

 Innervates the dorsal aspect of the U.E.  Spinal Cord Segments  C5  C6  C7  C8  T1

 Spinal Cord Segments  C5, C6, C7  Muscles Innervated  Pec. Maj.

 Gives rise to 2 nerves  Spinal Cord Segments  C5  C6  C7

 Gives rise to 5 nerves  Spinal Cord Segments  C5  C6  C7  C8  T1

 Gives rise to 5 nerves  Spinal Cord Segments  C8  T1

 Spinal Cord Segments  C8, T1  Muscles Innervated  Pec. Maj.  Pec. Min.

 Spinal Cord Segments  C5, C6  Muscles Innervated  Subscapularis

 Spinal Cord Segments  C6, C7, C8  Muscles Innervated  Lat. D.

 Spinal Cord Segments  C5, C6  Muscles Innervated  T. Maj.  Subscapularis

 Spinal Cord Segments  C8  T1

 Spinal Cord Segments  C8  T1

 Spinal Cord Segments  C8, T1  Muscles Innervated  FCU, FDP (4,5), PB, ADM, ODM, FDM, ADD POL, FPB (deep head), Lum (4,5) DI, PI

 Spinal Cord Segments  C5, C6  Muscles Innervated  T. Min.  Deltoid

 Spinal Cord Segments  C5, C6, C7, C8, T1  Muscles Innervated  Triceps, Anconeous, BR, Brachialis, ECRL

 Spinal Cord Segments  C5, C6, C7  Muscles Innervated  BB, CB, Brachialis

 Spinal Cord Segments  C5, C6, C7, C8, T1  Muscles Innervated  PT, FCR, PL, FDS, FDP (2,3), FPL, FPB, APB, OP, PQ, LUM (2,3).

 Due to traction  Traumatic injuries  Contusion  Disruption of blood supply  Laceration

 Fracture  Dislocation  Compression Sites  Low lesion  Ant. Interosseous lesion  Lesion proximal to elbow

Wasting of the thenar eminence and unable to oppose the thumb

 Fractures  Lacerations  Low Lesions  High Lesions

Cubital tunnel Guyon’s canal Midpalm

Wasting of hypothenar muscles, interossei, and two medial lumbricals

 Fractures  Dislocations  Posterior Interosseous Lesions  Mid-humeral Lesion  High Lesion  Sensory Loss

Anatomy of the Radial Nerve Deltoid tuberosity Radial Groove (Spiral Groove)

Wrist, thumb, and finger extensors weakness

 Brachial plexopathies require thorough understanding of anatomy  Specialized sensory and motor testing can help localize the pathology

Hoppenfeld, S., (2000). Physical examination of the spine and extremities. In S. Hoppenfeld (Ed.), Physical examination of the cervical spine and temporomandibular joint (p ). Norwalk, CT: Appleton and Lange