examination of brachial plexus

· technique dictated by sensation

Peripheral

· if numbness in distribution of peripheral nerve

· likely cord or nerve pathology

· start distally and work proximally

Dermatomal

· if numbness in dermatomal distribution or more extensive

· likely root or trunk pathology

· start proximally and work distally

sensation

Supraclavicular region

· C4

Regimental patch

· C5

· axillary nerve

Radial forearm

· C6

· lateral cutaneous nerve of forearm (musculocutaneous nerve)

Snuffbox

· C6

· radial nerve

Middle finger

· C7

· median nerve

Thumb and thenar eminence

· C6

· median nerve

Little finger

· C8

· ulnar nerve

Hypothenar eminence

· C8

· ulnar nerve

Ulnar forearm

· T1

· medial cutaneous nerve of forearm (median nerve)

Medial arm

· T2

Proximal

look

Front

· Horner’s syndrome

· ptosis

· miosis

· enophthalmos

· anhydrosis

· swelling in posterior triangle

· attitude of arm

· muscle wasting

Back

· muscle wasting

· winging of scapula

feel

· tenderness in posterior triangle

· Tinel’s sign in posterior triangle

move

· look and feel muscle belly

Adjacent nerves

Trapezius (CN XI)

· patient shrugs shoulders against resistance

Branches from the roots

Rhomboid (C5)

· nerve to rhomboid (dorsal scapular n)

· patient tries to push backwards with hand on back

Serratus anterior (C5,6,7)

· long thoracic n

· patient pushes against wall

· observe for winging

· patient protracts shoulder against resistance

Branches from the trunks

Supraspinatus (C5)

· suprascapular neve

· patient tries to initiate abduction of the arm from the side

Infraspinatus (C5)

· suprascapular nerve

· patient tries to externally rotate shoulder with arm by side

Branches of the posterior cord

Deltoid (C5)

· axillary nerve

· patient abducts arm against resistance

Latissimus Dorsi (C7)

· thoracodorsal nerve

· patient adducts horizonal arm against resistance

Branches of the medial cord

Pectoralis major (sternocostal fibres) (C7,8)

· medial pectoral nerve

· patient places hand on hip and pushes in

Branches of the lateral cord

Pectoralis major (clavicular fibres) (C6)

· lateral pectoral nerve

· patient pushes arm forwards with arm horizontal

Biceps (C5,6)

· musculocutaneous nerve

· patient tries to flex elbow with forearm supinated

Radial nerve

Brachioradialis (C6)

· patient flexes the elbow with forearm pronated

Triceps (C7)

· patient extends elbow against resistance

Supinator (C6)

· patient supinates forearm in extension

Wrist extension (C7-ECR, C8-ECU)

· radial and post. interosseous nerve

· patient extends wrist

· note deviation

Finger extension (C8-EDC)

· posterior interosseous nerve

· patient extends MCP jts

Extensor pollicis longus (C7)

· posterior interosseous nerve

· patient extends thumb IP jt against resistance

Median nerve

Pronation (C6)

· patient pronates arm

· in flexion (pronator teres - median nerve)

· in extension (pronator quadratus - anterior interosseous nerve)

Flexor carpi radialis (C6)

· median nerve

· patient flexes wrist against resistance

Flexor digitorum profundus (C8)

· anterior interosseous nerve

· patient makes fist and resists extension of index finger

Flexor pollicis longus (C8)

· anterior interosseous nerve

· patient flexes distal phalanx of thumb against resistance

Abductor pollicis brevis (T1)

· patient abducts thumb at right angles to palm against resistance

Ulnar nerve

Flexor carpi ulnaris (C8)

· ulnar n in forearm

· patient flexes wrist against resistance

Flexor digitorum profundus (C8)

· ulnar nerve in forearm

· patient makes fist and resists extension of index finger

Interossei (T1)

· ulnar n in hand

· if can extend fingers at MCP jts

· patient abducts and adducts fingers against resistance

· if cannot extend fingers at MCP jts

· patient abducts index finger (1st dorsal interosseous)

· can perform

· Froment’s sign

· card sign

Distal