Lateral Branches of the Brachial Plexus

from the brachial plexus lecture of midterm 1

Dorsal scapular nerve: root

C5

Dorsal scapular nerve: innervations

Levators and rhomboids

Dorsal scapular nerve: function

Elevate scapula & pull scapula to midline

Dorsal scapular nerve: clinical deficit

Unable to pull scapula back. Scapula’s further away from midline

Long thoracic nerve: Roots

C5,6,7

Long thoracic nerve: Innervation

Serratus anterior

Long thoracic nerve: Function

Keep scapula close to chest wall

Long thoracic nerve: Clinical deficit

Scapula winging

Subclavian n.: Roots

C5,6

Subclavian n.: Innervation

Subclavian

Subclavian n.: Function

Stabilizes clavicle

Subclavian n.: Clinical Deficit

None

Suprascapular n.: Roots

C5,6

Suprascapular n.: Innervation

Supraspinatus & infraspinatus

Suprascapular n.: Function

Shoulder abduction, external rotation

Suprascapular n.: Clinical deficit

• Weakness in shoulder abduction, external rotation

• Compensates by hiking shoulder

Lateral pectoral n.: Roots

C5,6,7

Lateral pectoral n.: Innervation

Pectoralis major

Lateral pectoral n.: Function

Shoulder flexion, adduction, internal rotation

Lateral pectoral n.: Deficits

Weakness in shoulder flexion, adduction, internal rotation

Upper subscapular n.: Roots

C5,6

Upper subscapular n.: Innervation

Subscapularis

Upper subscapular n.: Function

Shoulder internal rotation

Upper subscapular n.: Clincial deficit

Weakness in shoulder internal rotation, shoulder stability

Lower subscapular n.: Roots

C5,6

Lower subscapular n.: Innervation

Subscapularis, teres major

Lower subscapular n.: Function

• Shoulder internal rotation

• Adduction, internal rotation

Lower subscapular n.: Clinical Deficits

Weakness in shoulder internal rotation & adduction

Thoracodorsal n.: Roots

C6,7,8

Thoracodorsal n.: Innervation

Latissimus dorsi

Thoracodorsal n.: Function

Shoulder extension, adduction, internal rotation

Thoracodorsal n.: Clinical deficit

Weakness in shoulder extension, adduction, internal rotation

Medial pectoral n.: Roots

C8, T1

Medial pectoral n.: Innervation

Pectoralis major & minor

Medial pectoral n.: Function

• Shoulder flexion, adduction, internal rotation

• Scapula stabilization

Medial pectoral n.: Clinical deficit

Weakness in shoulder flexion, adduction, internal rotation & scapula stabilization

Medial brachial cutaneous n.: Roots

C8, T1

Medial brachial cutaneous n.: Innervation/Function

Sensation in medial and posterior arm

Medial brachial & antebrachial cutaneous n.: Clinical deficit

Sensory loss in corresponding area

Medial antebrachial cutaneous n.: Roots

C8, T1

Medial antebrachial cutaneous n.: Innervation/Function

Sensation in medial & ulnar forearm