Anatomy - Upper Limb

1. NERVE INJURIES

2. NERVE INJURIES
• CAUSE & SITE
• MOTOR
• MUSCLES PARALYSED
• MUSCLES ACTION DOMINATE
• DEFORMITY OF HAND
• SENSORY LOSS
• VASOMOTOR
• TROPHIC

3. BRACHIAL PLEXUS
•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

4. BRANCHES FROM ROOTS
& TRUNKS
ROOTS:
• Dorsal scapular nerve C5,
• Long thoracic nerve C5,6,7
UPPER TRUNK C5 C6
• Suprascapular nerve
• Nerve to subclavius

5. 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

6. • Erb’s palsy------upper trunk
• Klumpke’s palsy---- lower trunk
• Winging of scapula---- long thoracic nerve
• Axillary nerve injury
• Ape’ s hand---- median nerve
• Wrist drop------ Radial nerve
• Claw hand-----ulnar nerve

7. 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

8. Nerves involved:
• Supra scapular nerve
• Nerve to Subclavius
• Musculocutaneous nerve
• Axillary nerve
MUSCLES AND FUNCTIONS LOST
Lateral rotation of arm:- Teres minor,
Infraspinatus (arm medially rotated)
Abduction of shoulder- Supraspinatus,
Deltoid(arm adducted)
Flexion of shoulder: -corobrachialis, Biceps
brachii
Flexion of elbow:- Brachialis, Biceps brachii
(forearm extended)
Supination of forearm- Biceps brachii (pronated)
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

9. LOWER LESIONS OF BRACHIAL
PLEXUS
•Fibers of C8 and mostlyT1 root are torn
Cause:
Excessive abduction of arm
•Birth injury in breech delivery
•Person falling from a height clutching an
object to save himself
Compression of lower trunk
•Cervical rib
•Malignancy in lower deep cervical lymph
nodes

10. KLUMPKE,S PALSY
•Claw hand
•Hyperextension of metacarpophalangeal
joint----- by unopposed extensor digitorum
•Flexion at interphalangeal joint by
unopposed flexor digitorum superficialis
and profundus
Sensory loss
along the medial side of forearm
Nerves involved
T1 fibers run in ulnar and median nerve
Muscles involved
All small muscles of the hand( interossei and
lumbricals)

12. 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

13. 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
1.Fracture of surgical neck of humerus
2.Inferior dislocation of shoulder joint
3.Pressure of badly adjusted crutch upward into
armpit
4. Misplaced injection into deltoid

14. Muscles involved
•Deltoid – impaired abduction & loss
of shoulder contour
•Teres minor
Sensory loss
•Upper lateral cutaneous nerve of
arm
•Loss of skin sensation over the
lower half of deltoid muscle
(regimental badge anaesthesia)

16. RADIAL NERVE
Branches in axilla
• Posterior cutaneous nerve of ARM
• Nerve to long and medial head of triceps
Branches in spiral groove
• Lower lateral cutaneous nerve of arm
• Posterior cutaneous nerve of forearm
• Nerve to lateral and 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 for dorsum of hand

19. 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
•Deformity known as WRIST DROP -----flexion of wrist as
a result of action of unopposed flexors of wrist and fingers
•Loss of supination in extended elbow due to paralysis of supinator
Sensory loss
•posterior surface of arm and fore arm
•Dorsum of hand and dorsal surface of lateral 3 ½ fingers

20. 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

21. 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
•Enter palm superficial to flexor retinaculum
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
•Deep branch of ulnar
•All small muscles of hand except of thenar muscles and first 2 lumbricals

22. 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 & flattening of hypothenar eminence
•Terminal phalanges of little and ring finger can not be flexed (3 &4 lumbricals
and interossei)
•Inability to abduct and adduct fingers flexed (interossei)
•Loss of adduction of thumb flexed (adductor pollicis)
•Forment’s sign flexion of terminal phalanx of thumb while attempting adduct
the thumb in ulnar nerve palsy
•CLAW HAND
1.Metacarpophalangeal joints of fourth and fifth finger are hyper extended
2. Interphlangeal joint of fourth and fifth fingers are flexed
•Flattening of hypothenar eminence
•Hollowing between metacarpals on dorsum of hand due to paralysis of dorsal
interossei
Sensory loss
•Anterior and posterior surfaces of medial half of hand and medial one and half

23. 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 because FDP is not paralysed so marked flexion at DIP
•Inability to abduct and adduct fingers flexed (interossei)
•Flattening of hypothenar eminence
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

27. 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 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

28. INJURY TO MEDIAN NERVE AT ELBOW
Cause:
•Supracondylar fracture of humerus
Motor loss
•Loss of pronator of forearm (supinated)
•Loss of long flexors of wrist and fingers except medial half of
flexor digitorum profundus and flexor carpi ulnaris (Wrist----flexion
is weak accompanied by adduction)
•Loss of flexion of terminal phalanx of thumb due to paralysis of
FPL
•Loss of flexion of interphalangeal joint of index and middle
finger (Benediction deformity)
•Loss of thenar muscles (wasted)
Deformity:
Forearm ----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

30. 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 t o reduced size of canal
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

31. CARPAL TUNNEL SYNDROME
Cause
• Tenosynovitis of flexor tendons
• Myxedema
• Retention of fluid in pregnancy
• Fracture dislocation of lunate
• osteoarthritis
Features
Sensory
• feeling of burning pain in lateral three and
half digits especially at night
Motor
• weakness of thenar muscles
• ape thumb deformity
• Positive Tinel’s sign and Phalen;s test