NERVES OF UPPER LIMB AND THEIR
INJURIES
LEARNING OBJECTIVES
• Revise the course and branches of nerves of upper limbs
• Understand Injuries associated with these nerves
• Know causes and motor and sensory loss associated with
nerve injuries of upper limb
• Know deformities associated with these nerves
BRACHIAL PLEXUS
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Present in neck and axilla
Formed by ventral primary rami of C5-T1
ROOTS
C5+C6=UPPERTRUNK
C7---- MIDDLE TRUNK
C8+T1 = LOWER TRUNK
All trunk divides into anterior and posterior
DIVISIONS
Anterior divisions of upper and middle trunk unite
to form LATERAL CORD
Anterior division of middle trunk continues as MEDIAL CORD
Posterior divisions of all 3 trunk form POSTERIOR CORD
BRANCHES FROM ROOTS & TRUNKS
ROOTS:
Dorsal scapular nerve C5, Long thoracic
nerve C5,6,7
UPPER TRUNK C5 C6
Suprascapular nerve , Nerve to
subclavius
BRANCHES FROM LATERAL CORD
 Lateral pectoral nerve
 Musculocutaneous nerve
 Lateral root of median
BRANCHES FROM MEDIAL CORD
 Medial pectoral nerve
 Medial cutaneous nerve of arm and
forearm
 Ulnar nerve
 Medial root of median
BRANCHES FROM POSTERIOR CORD
 Upper and lower subscapular nerves
 Thoracodorsal
 Axillary nerve
 Radial nerve
BRACHIAL PLEXUS INJURIES
1. Upper lesions of brachial plexus
Erb duchenne palsy
2. Lower lesions of brachial plexus
Klumpke palsy
UPPER LESION OF BRACHIAL PLEXUS
• Traction or even tearing of C5 and C6 root
• Cause:
• Excessive displacement of head to opposite
side and depression of shoulder on same side
• In infants during a difficult delivery
• In adults following a fall on or a blow to the
shoulder
Nerves involved:
Supra scapular nerve, Nerve to Subclavius Musculocutaneous nerve
,Axillary nerve
MUSCLES AND FUNCTIONS LOST
Lateral rotation of arm:
• Teres minor
• Infraspinatus
Abduction of shoulder
• Supraspinatus
• Deltoid
Flexion of shoulder:
• corobrachialis
• Biceps brachii
Flexion of elbow:
• Brachialis
• Biceps brachii
Supination of forearm
• Biceps brachii
ERB’S PALSY (UPPER TRUNK INJURY)
• Loss of muscle function innervated by C5 and C6
• Also known as waiter’s tip or policeman’s tip
• Arm medially rotated, adducted, hangs by side
• Forearm extended and pronated
LOWER LESIONS OF BRACHIAL PLEXUS
• Fibers of C8 and mostlyT1 root are torn
Cause:
Excessive abduction of arm
a) Birth injury in breech delivery
b) Person falling from a height clutching an object to
save himself
Compression of lower trunk
a) Cervical rib
b) Malignant mets in lower deep cervical lymph nodes
Nerves involved
T1 fibers run in ulnar and median nerve
Muscles involved
All small muscles of the hand( interossei and lumbricals)
Sensory loss
along the medial side of forearm
KLUMPKE,S PALSY
• Clawed hand
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Hyperextension of metacarpophalangeal joint----- by
unopposed extensor digitorum
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Flexion at interphalangeal joint by unopposed flexor
digitorum superficialis and profundus
LONG THORACIC NERVE
• Arise from roots c5 , c6 and c7
Muscles involved
Serratus anterior
Functions lost
Abduction above 90 degrees
Causes:
• Blows or pressure in posterior triangle of neck
• In radical mastectomy
Deformity
Winging of scapula vertebral border and inferior
angle of scapula unduly prominent
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AXILLARY NERVE
From posterior cord
Important landmarks
Axilla
quadrangular space
scapular region
In quadrangular space----close relation with shoulder joint
and surgical neck of humerus
Terminates by dividing into anterior and posterior branches
AXILLARY NERVE INJURY
• Arise from posterior cord of brachial plexus
Causes
a. Fracture of surgical neck of humerus
b. Inferior dislocation of shoulder joint
c. Pressure of badly adjusted crutch upward into armpit
d. Misplaced injection into deltoid
Muscles involved
 Deltoid
 Teres minor
Sensory loss
 Upper lateral cutaneous nerve of arm
 Loss of skin sensation over the lower half of deltoid muscle
RADIAL NERVE
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Largest branch of plexus
From posterior cord
Arise in axilla --- spiral groove - lateral
intermuscular septum - front of lateral
epicondyle - divides into superficial and deep
Superficial -- lateral side of radial artery
posterior surface of wrist
Deep branch
supinator
neck of radius
posterior surface of wrist
RADIAL NERVE
Branches in axilla
• Posterior cutaneous nerve of ARM
• Nerve to long head of triceps
• Nerve to medial head of triceps
Branches in spiral groove
• Lower lateral cutaneous nerve of arm
• Posterior cutaneous nerve of forearm
• Nerve to lateral head of triceps
• Nerve to medial head of triceps
Branches in anterior compartment of arm:
• Nerve to small part of brachialis
• Nerve to brachioradialis
• Nerve to extensor carpi radialis longus
Branches in cubital fossa:
• Deep branch of radial nerve to extensor carpi radialis brevis, supinator
and all muscles in posterior compartment of forearm
• Superficial branch provides sensation to dorsum of hand and dorsum of
Branches in distal fore arm
• Palmar cutaneous branch----skin on lateral side of palm
Branches in palm
• Muscle of thenar eminence
• First 2 lumbricals
• Skin of palmar surface of lateral 3 ½ fingers
• lateral 3 ½ fingers
RADIAL NERVE INJURIES IN AXILLA
Causes
• Pressure of badly fitted crutch into armpit
• Falling asleep with arm over the back of chair-----Saturday night palsy
Motor loss:
• Extension at elbow----- paralysis of triceps and
anconeus
• Extension of wrist and fingers-----paralysis of
extensors of wrist and all muscles of posterior
compartment
• Supination----can still be performed by
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Deformity known as WRIST DROP -----flexion of wrist as a result of action
of unopposed flexors of wrist and fingers
Sensory loss
• posterior surface of arm and fore arm
• Dorsum of hand and dorsal surface of lateral 3 ½ fingers
RADIAL NERVE INJURY IN SPIRAL GROOVE
• Most commonly in distal part of groove beyond the
origin of nerves to triceps and anconeus and
cutaneous nerves
Causes:
• Fracture of shaft of humerus
• Prolonged pressure on the back of arm as in
• Unconscious patient by edge of operating table
• Prolonged application of tourniquet in thin lean
person
Motor loss:
 Extension of wrist, fingers and thumb
 Elbow extension is spared
Sensory loss:
• Dorsum of hand and dorsum of lateral 3 ½ fingers
• Sensations on posterior arm and forearm are spared
MEDIAN NERVE
 Formed in axilla by lateral and medial roots from
respective cords
 Anterior compartment of arm ---- crosses brachial artery
from lateral to medial
 At elbow crossed by bicipital aponeurosis
 Passes between 2 heads of pronator teres to enter
forearm
 At wrist at lateral border of flexor digitorum profundus
 Enter palm beneath flexor retinaculum
Branches in axilla and arm
 no branches
Branches in proximal forearm
 To all anterior compartment muscles except flexor carpi ulnaris and
medial half of flexor digitorum profundus
Branches in distal fore arm
 Palmar cutaneous branch----skin on lateral side of palm
Branches in palm
 Muscle of thenar eminence
 First 2 lumbricals
 Skin of palmar surface of lateral 3 ½ fingers
INJURY TO MEDIAN NERVE AT ELBOW
Cause:
• Supracondylar fracture of humerus
Motor loss
• Loss of pronator of forearm
• Loss of long flexors of wrist and fingers except medial half of
flexor digitorum profundus and flexor carpi ulnaris
• Loss of flexion of terminal phalanx of thumb
• Loss of thenar muscles (wasted)
Deformity:
Forearm ----supinated
Wrist----flexion is weak accompanied by adduction
Fingers----no flexion of interphalangeal joint of index and middle
Thumb---flexion, abduction and opposition is lost
APE’S HAND----thumb laterally rotated adducted and thenar
eminence flattened
Sensory loss
• Lateral side of palm
• Palmar surface of lateral 3 ½ fingers
• Distal part of dorsal surface of lateral 3 ½ fingers
INJURY TO MEDIAN NERVE AT WRIST
• Most common injury of median nerve
Causes
• Due to penetrating injuries or stab wound at the wrist
Motor loss
• Muscle of thenar eminence
• First two lumbricals
Deformity APE’S HAND
Sensory loss
• Same as in elbow lesion
INJURY TO MEDIAN NERVE IN CARPAL TUNNEL
• Carpal tunnel---Osseo fibrous space formed by anterior
concave surface of carpus and flexor retinaculum
• Passage of long flexor tendon and median nerve
Syndrome is caused by compression of median nerve due
reduced size of canal
to
Causes
• Inflammation of retinaculum
• Arthritis of carpal bones
• Inflammation of synovial sheaths of flexor tendons
Sensory and motor Loss:
• Pain and paraesthesia of lateral one and half finger
• Weakness of thenar muscle
ULNAR NERVE
• Arise from medial cord in axilla
• Descends between axillary artery and vein
• In anterior compartment of arm on medial side of brachial
artery
• Pierces medial intermuscular septum to enter in posterior
compartment
• At elbow lies behind medial epicondyle
• Enter forearm between 2 heads of flexor carpi ulnaris
• At wrist between tendons of flexor carpi ulnaris and
digitorum profundus
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Enter palm superficial to flexor retinaculum
Branches in axilla or arm
• No branches
Branches in proximal forearm
• Nerve to flexor carpii ulnaris
• Medial half of flexor digitorum profundus
Branches in distal forearm
• Palmar cutaneous branch -----skin of
hypothenar eminence
• Posterior cutaneous branch----skin of medial third of dorsum of hand and
dorsal side of medial one and half finger
Branches in palm
• Superficial branch of ulnar---- skin of palmar surface of medial one and
half finger
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Deep branch of ulnar
All small muscles of hand except of thenar muscles and first 2 lumbricals
ULNAR NERVE INJURY AT THE ELBOW
• Most commonly injured at this site
Cause
• Fracture of medial epicondyle
Motor loss
• Flexor carpi ulnaris and medial half of flexor
digitorum profundus
• Small muscle of hand are paralyzed except thenar
muscles and first 2 lumbricals
Deformity
• Wasting of ulnar border of forearm
• Terminal phalanges of little and ring finger can not be flexed
• Inability to abduct and adduct fingers
• Loss of adduction of thumb
• Forment’s sign flexion of terminal phalanx of thumb while attempting
adduct the thumb in ulnar nerve palsy
• CLAW HAND
a. Metacarpophalangeal joints of fourth and fifth finger are hyper
extended
b. Interphlangeal joint of fourth and fifth fingers are flexed
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Flattening of hypothenar eminence
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Hollowing between metacarpals on dorsum of hand due to paralysis of
dorsal interossei
Sensory loss
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Anterior and posterior surfaces of medial half of hand and
medial one and half fingers
ULNAR NERVE INJURY AT WRIST
• Due to superficial position
Causes
• Penetrating wounds
Motor loss
• Small muscles of hand except those of thenar
eminence and first 2 lumbricals
Deformity
• Claw hand more prominent
Sensory loss
• On the medial side of palm and palmar and dorsal surface of 1 ½ fingers
• Sensation on posterior medial surface of hand is intact
summary
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Erb’s palsy------upper trunk
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Klumpke’s palsy---- lower trunk
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Winging of scapula---- long thoracic nerve
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Ape’ s hand---- median nerve---- supracondylar fracture
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Wrist drop------ Radial nerve---fracture of spiral groove
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Claw hand-----ulnar nerve----- fracture of medial epicondyle