nerves of upper extremity

1. NERVES OF UPPER
EXTREMITY
MAJ DR POONAM SINGH
DEPT OF ANATOMY
NAIHS

2. OBJECTIVES
ORIGIN, ROOT VALUE, COURSE, BRANCHES
AND APPLIED OF MAJOR NERVES OF UPPER
EXTREMITY

3. BRACHIAL PLEXUS- imp nerves

4. BRACHIAL PLEXUS: NERVES
DISTRIBUTION OF MAIN NERVES
– AXILLARY –
• Deltoid & Teres minor
– MUSCULOCUTANEOUS –
• Muscles of Anterior Compartment of arm
(flexors)
– MEDIAN –
• Most of the Flexor muscles of forearm &
Intrinsic muscles in hand- labourer
– ULNAR –
• FCU & part of FDP (forearm) and Intrinsic
muscles in hand- musician
– RADIAL –
• Innervates all Extensor muscles of arm &
forearm

5. MUSCULOCUTANEOUS NERVE

6. MUSCULOCUTANEOUS NERVE
– Arise opposite lower border of Pectoralis Minor.
– Derived from C5-C7 cervical ventral rami
Course :
 Supplies Coracobrachialis and then
pierces it.
 Descends laterally between Biceps and
Brachialis to lateral side of arm.
 Just below elbow it pierces deep fascia.
 Continues as lateral cutaneous nerve of
forearm..

7. – Supplies –
Coracobrachialis,
Biceps and
most of Brachialis.
Branch to Brachialis
supplies Elbow joint.
Br to humerus via
nutrient art

8. LESIONS OF MUSCULOCUTANEOUS NERVE
Commonest causes
–Isolated lesion is rare.
–injuries to
• upper arm and
• shoulder including
fracture of humerus.

9. LESIONS OF MUSCULOCUTANEOUS NERVE
Symptom and sign
– Marked weakness of elbow flexion
• because of paralysis of
– biceps brachii and much of
– brachialis
– Sensory impairment
• on the extensor aspect of the forearm in the distribution of
lateral cutaneous nerve of the forearm.

10. AXILLARY NERVE

11. AXILLARY (CIRCUMFLEX) NERVE
– From posterior cord (C5 - C6) .
– Posterior to Axillary artery (3rd
part) and anterior to
Subscapularis,
– Above posterior circumflex
humeral vessels, traverses
quadrangular space.
– Axillary trunk supplies a branch
to shoulder joint.

12. BRACHIAL PLEXUS- POST CORD Axillary N cont’d
Divides into
• anterior and
• posterior branches.
Anterior branch
along posterior circumflex
humeral vessels,
curves behind the humeral neck,
Supplies
– Deltoid (deep to).
– skin over its middle part.(cutaneous branches which pierce the
muscle)

13. Posterior branch
Anterior br of Axillary
Nerve

14. Posterior branch
supplies
– Teres minor
» Branch to Teres minor has a pseudoganglion
– posterior and lower part of Deltoid.
– upper part of long head of Triceps
– upper lateral cutaneous nerve of arm

15. • Commonest causes
• Dislocations of shoulder
• Fractures of upper end humerus
• Misplaced injections into deltoid
• Symptom and sign
• Wasting and weakness of Deltoid-
• abduction of shoulder affected.
• sensory loss on outer aspect of upper arm below
acromion.
LESIONS OF AXILLARY NERVE

16. MEDIAN NERVE

17. 17
MEDIAN NERVE
• Formed by two roots:
– Medial & Lateral roots
• Contribution from both cords
– Medial Root -
• derived from Medial cord, C8 &
T1
– Crosses downward and
laterally infront of 3rd part of
Axillary and join Lateral root)
– Lateral root –
• continuation of lateral cord, C5
to C7
• Supplies flexors of forearm
• Labourer’s Nerve
• Thickest nerve of Brachial
Plexus
FORMATION

18. • Formed in Axilla
• lateral to 3rd part of Axillary artery
18
MEDIAN NERVE: COURSE

19. 19
In arm-
Nerve descends
lateral to Brachial
artery
In middle of arm
 crosses in front of
artery
 runs on its medial side
to Cubital fossa

20. 20
At elbow-
 lies deep to
Bicipital
aponeurosis
 in front of
Brachialis
 Medial to
Brachial art

21. 21
MEDIAN NERVE: COURSE
Forearm
─ Enters forearm
─ Bt two heads of Pronator Teres
─ Then passes deep to
tendinous bridge
─ (formed by humero-ulnar &
radial heads of FDS)
─ Descends bt
─ FDS & FDP in forearm
─ 5 cm above Flexor
retinaculum
─ emerges from behind lateral
edge of FDS

22. 22
passes deep to tendinous
bridge of FDS
─formed by humero-ulnar &
radial heads of FDS

23. 23
Descends between
─ FDS & FDP in forearm

24. 24
5 cm above Flexor
retinaculum
─ emerges from behind
lateral edge of FDS

25. 25
MEDIAN NERVE: COURSE
wrist
– becomes
superficial
– bt FDS & FCR
tendons)
– Passes deep to
flexor retinaculum
to enter palm

26. 26
BRANCHESIN ARM
1. Vascular brs (symp twigs ) to brachial artery
2. Branch to pronator teres above elbow
IN FOREARM
1. Muscular brs
a). Trunk of median nv Flexors of forearm except FCU &
medial half of FDP
b). Ant Interrosseous nv arise from median nv as it passess
between 2 heads of PT
- Runs infront of Interrosseous membrane
- supplies Deep flexors:- Lat ½ of FDP, FPL & PQ
- Supplies joints
Distal Radio- Ulnar joint
Radio- Carpal joint
Carpal joints

27. 27
MEDIAN NERVE:
BRANCHES
Forearm cont’d
2. ARTICULAR
- Elbow joint
- Proximal R- U joint
3. PALMAR CUTANEOUS
– Given proximal to flexor
retinaculum
– Passes over retinaculum.
Supplies
– central palm,
– Skin thenar eminence,
4. COMMUNICATING
Frequently present.
To ulnar nerve.

28. 28
MEDIAN NERVE: BRANCHES
IN HAND
1. Recurrent branch
• recurrent branch – supplies
Thenar muscles
2. Lateral branch / Main Nerve
– Lateral branch divides into
• 3 proper palmar digital
branches.
Supply:
1. skin of thumb
2. Lat side of index finger.
3. Supplies msls:
• 1st lumbrical.

29. 29
MEDIAN NERVE:
BRANCHES
2. Medial branch
– Divides into
• two common palmer digital
nerves.
• These further divide into
Proper palmer digital nerves
Supply:
1. Sides of index, middle & half
of ring fingers.
2. 2nd lumbrical
summary
• All proper palmar digital nerves reach
on dorsum of Hand to supply nail
beds and palmar aspect of lateral 3 ½
fingers
• Lateral two lumbricals supplied by
Median

30. 30
MEDIAN NERVE: BRANCHES

31. 31
MEDIAN NERVE: CUTANEOUS INNERVATION
PALM

32. 32
MEDIAN NERVE: CUTANEOUS INNERVATION
DORSUM OF HAND- short of nailbeds

33. 33
MEDIAN NERVE - APPLIED
• Median Nerve Injury At Elbow
• Carpal Tunnel Syndrome
• Pronator Syndrome

34. 34
MEDIAN NERVE INJURY AT ELBOW
• All muscles paralyzed except FCU & FDP (medial half)
• MOTOR LOSS
1. FDS & FDP ( LAT. HALF) –
• Loss of flexion at MP & IP Jts
(OCHSNER’S CLASPING TEST – When patient asked to clasp the hands, index finger of
affected side fails to flex – remains as Pointing Index Finger)
2. FCR -
• Loss of flexion of wrist
• Ulnar deviation on attempts of flexion of wrist.
3. FPL -
• Inability to flex terminal phalanx of thumb.
4. PQ and PT – pronation lost
5. Thenar eminence : muscles of thenar region affected –
• Flattening of eminence.
• Ape like hand
• Abductor Pollicis Brevis and Opponens Pollicis– Paralysis.
(PEN TEST : Hand laid flat on table. Patient asked to touch a pen kept at slightly higher level
than palm with the thumb)

35. 35
MEDIAN NERVE INJURY AT ELBOW
INJURY RESULTS IN
1. Loss of pronation :
• PT & PQ
2. Loss of powerful flexion at wrist :
• FCR & FDS (wrist deviates to ulnar side)
3. Loss of flexion of PIP of all digits :
• FDS is paralyzed
4. Loss of flexion of DIP & MCP Joints of index and
middle fingers
• FDP – lat. ½ &
• Lumbricals 1st , 2nd paralyzed)
5. Loss of flexion, abduction & opposition of thumb :
• Thenar muscles paralyzed
Thumb in adducted & extended position : APE LIKE HAND

36. 36
CARPAL TUNNEL SYNDROMEMost common entrapment
mononeuropathy
Incidence -
• females over 50 years.
• 50% cases B/L. Mostly in dominant
hand.
Cause -
• Compression of Median nerve in fibro-
osseous tunnel beneath flexor
retinaculum.
Tunnel may be narrowed by
a) Arthritic changes in wrist joint (RA)
b) Anterior dislocation of Lunate /
complication of Colle’s fracture
c) Soft tissue thickening in
Myxoedema & Acromegaly
d) Oedema, Obesity, Pregnancy

37. 37
CARPAL TUNNEL SYNDROME
Symptoms
1. impairment of finer movements
• (sewing, knitting, picking a pin)
2. paresthesia -
• attacks of pain, tingling & numbness of radial 3
½ digits of affected hand.
• wakes patient at night.

38. 38
CARPAL TUNNEL SYNDROME cont’d
On examination
– Wasting Of Thenar Eminence –
• Muscle affected: AbPB & OP
– Hypo aesthesia –
• palmar aspect of radial 3 ½ digits.
• skin over thenar eminence and palm not affected
– as it is supplied by palmar cutaneous br of median N which
arise proximal to carpal tunnel.
– Tinel’s Sign –
• Percussion of Median nerve gently at wrist
– causing tingling sensation radiating into hand.
Tinel’s

39. 39
CARPAL TUNNEL SYNDROME cont’d
• Wrist Flexion Test (Phalen’s Sign) –
• Exacerbation of symptoms when patient is asked to flex
wrist. Symptoms disappear as wrist straightened.
surgical treatment –
– Carpal tunnel release.
– Partial or complete division of flexor retinaculum

40. 40
Thenar atrophy

41. 41
PRONATOR SYNDROME
• Uncommon entrapment neuropathy of Median Nerve
• Anatomical basis
– Deep to Biceps aponeurosis
– Between two heads of Pronator Teres
– Through a fibrous arch of Flexor Digitorum Superficialis
• Clinical Features:
1. Pain & tenderness
• in proximal aspect of anterior forearm.
2. Weakness of all muscles innervated by Median nerve.
• Including Abductor Pollicis Brevis & long finger flexors.
3. Sensory impairment on palm of hand.

42. ULNAR NERVE

43. ULNAR NERVEFORMATION
- Branch of Medial cord.
- One of the terminal branch.
- Supplies small muscles in
hand that are involved in fine
intricate hand movements
- Called MUSICIAN’S Nerve.
ROOT VALUE:- (C7) C8-T1
- C7- contribution from median N (lat
cord)
43

44. ULNAR NERVE : COURSE
Axilla
• Forms in Axilla.
• Runs on medial side
of axillary artery
44

45. ULNAR NERVE : COURSE
arm
• runs medial to Brachial Artery till middle.
• Pierces IM septum &
• enters posterior compartment.
• Descends in front of medial head of Triceps along
superior ulnar collateral artery (br of Brachial
Art)
45

46. Ulnar nerve medial to
artery
Enters posterior
compt by piercing
medial IM septum
46

47. Ulnar nerve lies
infront of medial head
of triceps
and then behind the
medial epicondyle
47

48. ULNAR NERVE : COURSE
elbow
• lies in a groove on
dorsal aspect of
medial epicondyle
• interval bt medial
epicondyle and
olecranon process.
48

49. ULNAR NERVE : COURSE
forearm
• Enters forearm
• bt humeral & ulnar heads of FCU (Cubital Tunnel)
• Runs downwards
• in medial side of forearm.
49

50. COURSE
• Rest on
• FDP and under cover of FCU.
• Ulnar artery is radial to nerve.
• Gives
 palmar cutaneous
(hypothenar eminence)and
 dorsal branch
• Enters palm by passing over
flexor retinaculum 50
Ulnar N rest on
FDP undercover of
FCU which has
been removed
here

51. ULNAR NERVE : COURSE
wrist
• enter palm by passing over
flexor retinaculum.
• Ulnar N lies lateral to
pisiform and
• medial to hook of
hamate.
• Ulnar art is lateral to
Nerve
51

52. COURSE
• Both are bridged over
• by a slender band of fibrous
tissue (superficial part of
retinaculum)volar carpal lig
• forming a canal – GUYON’S
CANAL.
Palm
• In palm it passes deep to
Palmaris brevis
• and divides into
• superficial &
• deep branches. 52

53. 53

54. In palm it
passes deep to
Palmaris brevis
Right palm
54

55. Ulnar N lies lateral
to pisiform and
medial to hook of
hamate.
Right palm
55

56. Right palm
56

57. ULNAR NERVE : COURSE
IN PALM
Superficial branch –
• supplies
• Palmaris Brevis &
• skin on medial 11/2 side of hand.
• Divides into
• 2 palmar digital nerves
• can be compressed against hook of
hamate
• 1st palmar digital branch –
• medial side of little finger
• 2nd palmar digital branch –
• adjacent sides of little & ring
fingers 57

58. 58

59. ULNAR NERVE : COURSE IN PALM
Deep branch –
• Passes bt
• Abductor & Flexor digiti minimi and
• then bt
• Opponens Digiti Minimi & 5TH Metacarpal.
• Follows course of deep palmar arch deep to
flexor tendons.
59

60. Supplies :
1. Hypothenars ,
2. Interossei – dorsal and
palmar
3. Lumbricals 3rd & 4th
4. Adductor Pollicis (at
times Flex Poll Brevis)
• Ends by supplying
Adductor Pollicis –
Grave yard
60

61. Ulnar N
Deep branch
entering bt
abductor digiti
minimi and
flexor digiti
minimi
61

62. Passes bt
Abductor &
Flexor digiti
minimi
and
then bt
Opponens
Digiti Minimi
& 5TH
Metacarpal.
Right palm
62

63. ULNAR NERVE : Branches
1. ARTICULAR
a) Elbow joint
b) Wrist joint
c) Small joints of hand-
– intercarpal and
– carpometacarpal joints
2. CUTANEOUS
a) Palmar cutaneous branch :
• Skin of hypothenar eminence
b) Dorsal branch :
• Dorsal 1 ½ digits (medial) on dorsum of hand
3. MUSCULAR AT FOREARM
a) FCU
b) FDP (med. Half) 63

64. 4. TERMINAL
a) Superficial branch :
• Supplies Palmaris Brevis & medial 1 ½ digits
b) Deep branch : (muscular)
Supplies
a. Hypothenars :
• Ab Digiti Minimi,
• Flex Digiti Minimi,
• Opponens Digiti Minimi
b. Interossei :
• All 4 Dorsal & 4 Palmar
c. Lumbricals :
• 3rd & 4th (medial two)
d. Thenar :
• Adductor Pollicis & Flex. Poll. Brevis (sometimes)
5. VASCULAR
Vascular twigs to Axillary, Brachial, Ulnar and Deep palmar arch.
64

65. MUSCLES SUPPLIED IN FOREARM
These muscles are
primarily flexors of the
wrist and fingers
FCU
FDP (Med.half)
65

66. MUSCLES SUPPLIED IN FOREARM
FCU
FDP (Med. half)
66

67. MUSCLES SUPPLIED IN HAND
Palmar
aspect
Dorsal
aspect
67

68. ULNAR NERVE: CUTANEOUS INNERVATION OF HAND
SUPERFICIAL BRANCH OF RADIAL
PALM DORSUM
MEDIAN
ULNAR
ULNAR
68

69. LESIONS OF ULNAR NERVE
1. AT THE WRIST
• Ulnar nerve may be compressed in
• Guyon's canal or
• deeply thro msl of hypothenar eminence
• trough formed by pisiform medially and hook of
hamate laterally
• Tight pisohamate lig
69

70. • Preservation of
• FDP to ring and little fingers.
• Dorsal cutaneous branch and palmar branch of Ulnar
nerve are spared –
• lesion is distal to their origin from main trunk of
Ulnar nerve in forearm
• Lesion of
• Superficial (to digits) and deep branches (intrin msls)
• Presentation
• Ulnar claw hand (medial two fingers are extended at
MCP jt and flexed at the IP jt.
• Hypo aesthesia medial 1 ½ fingers 70

71. LESIONS OF ULNAR NERVE
2. AT THE ELBOW
Ulnar nerve lesion due to :
1. vulnerable position –
• lies between medial epicondyle & olecranon:
• lies on bone covered only by a thin layer of skin.
• Easily damaged if ulnar groove is shallow.
2. Cubital tunnel syn
• Entrapment neuropathy bt two heads of FCU
71

72. LESIONS OF ULNAR NERVE
Presentation
• Weakness of FDP
• affect ring & little fingers.
• Produce ulnar claw hand with straighter fingers
• Called “ulnar paradox” – lower lesion has more claw feature
• All intrinsic msls of hand and sensations lost
• Radial deviation of wrist on flexion
72

73. LESIONS OF ULNAR NERVE
3. HAND
• Deep motor branch of Ulnar nerve compressed against
pisiform & hamate
• - When hand is used as a mallet, or if a vibrating tool or motorcycle handlebar
is held in such a way that Hypothenar eminence is off the edge of the handle.
• Sensory branches are always spared.
• involvement of hypothenar muscles is variable. (depends on
the level at which branches to these muscles arise)
73

74. Ulnar claw hand with
lesion at wrist
FDP spared
74

75. Ulnar claw hand
FDP affected – lesion
higher level
75

76. True claw hand – due to
lesion of ulnar and
median N
76

77. RADIAL NERVE

78. 78
RADIAL NERVE
Nerve of Extensors of
- arm
- forearm
Sensory to
- back of arm
- back of forearm
- dorsum of hand
FORMATION:-
•continuation of Posterior Cord
• Root value: C5-C8 & T1
• Largest branch of Brachial Plexus

79. 79
RADIAL NERVE: COURSE
Descends
–behind 3rd part
of Axillary artery
&
–later behind
brachial art.

80. 80
In axilla
anterior to
Subscapularis &
tendons of LD
& T Major

81. 81
Leaves axilla
thru triangular
space along with
Profunda brachii

82. 82
arm
At first Lies bt long &
medial heads of Triceps.
Passes obliquely and
enters spiral groove
across post surf of
humerus bt lateral &
medial heads of Triceps.
Here it covered by lat
head.
Enter anterior
compartment

83. 83
Showing relation of
radial nerve to
humerus and vessels

84. 84
RADIAL NERVE: COURSE con’td
Descends
– bt Brachialis & Brachioradialis
(proximally)
– and ECRL (distally)
Anterior to lateral Epicondyle-
– Divides into terminal branches:
a) Superficial branch
b) Posterior Interosseous
nerve (Deep br)

85. 85

86. 86
Ant. to lat. Epicondyle –
Divides into terminal
branches :
•
Post. Interosseous nerve
(Deep branch)
•
Superficial branch

87. 87
Superficial branch
– descends along radial
border of forearm.
– Crosses anatomical
snuff box
– Reach back of hand
– Sensory to
• dorsum of hand (lat.
2/3rd)
• small area over palm.
• Lateral 3 1/2 fingers
short of nail beds
Flexor aspect

88. Anatomical snuff box
88

89. 89
Deep branch
– Pierces Supinator
– enters extensor Compt of
forearm.
Flexor aspect

90. 90
Deep branch
Supplies extensors of
forearm.
Supinator
ECRB, (BR, ECRL??)
ED,
EDM,
ECU,
AbPL, EPB, EPL,
EI

91. 91

92. 92
RADIAL NERVE: REGION WISE BRANCHES
IN AXILLA ( 2 muscular & 1 cut)
1. Post Cutaneous N of arm
2. A br to long head of triceps
3. A br to medial head of triceps

93. IN SPIRAL GROOVE (muscular,
cut & articular)
1. Lower lat cut N of arm
2. Post cut N of forearm
3. Lateral & medial head of
triceps ANCONEUS,
articular twigs to the
elbow jt.
93

94. 94
Branches to triceps
Triceps supplied by 4
branches from radial N.
• Medial head : 2 br,
• long head : 1 br,
• lateral head : 1 br

95. 95
BEYOND RADIAL GROOVE ( in the
lower part of arm)
(Above lateral Epicondyle)
– Brachialis Lateral part
– Brachioradialis
– Extensor Carpi Radialis
Longus (ECRL)
– Elbow joint
– Then it divides into two
branches

96. 96
RADIAL NERVE: REGION WISE BRANCHES
IN CUBITAL FOSSA
1. Posterior interosseous
nerve (Deep branch)
2. Branch to Supinator
3. Superficial br-
• supply
• skin of lat side of dorsum of
hand and
• dorsum of lat 3 ½ fingers
proximal to nail beds.

97. 97
RADIAL NERVE: BRANCHES
Branches
1. Muscular
2. Cutaneous
3. Articular
1. Muscular
• Long, medial and lateral head of triceps
• Anconeus
• Extensor muscles
2. Cutaneous branch
• Posterior cut N of arm
• Lower lateral cut N of arm
• Posterior cut N of forearm
• Superficial br of radial (terminal)
3. Articular br
• Elbow jt
• Wrist and intercarpal

98. 98
RADIAL NERVE : APPLIED
studied under
1. Injury to N in axilla
2. Injury of N in spiral groove
3. Injury of Deep branch – Post interosseous N
4. Injury to superficial br

99. 99
RADIAL NERVE : APPLIED
1. Injury at axilla
• Causes
1. Extra long crutches (CRUTCH PALSY)
2. Fracture dislocation of upper humerus
3. During reduction of shoulder dislocation
• Symptoms
a) Motor:
– All extensors of wrist, elbow, finger paralyzed. Unopposed
action of flexors
– WRIST DROP
– Fingers can be extended (extension of IP jts) –
• done by lumbricals and interosseous (supplied by median/ulnar N)
– Inability to grip objects firmly.
• (flexors working with decreased mechanical advantage, b’coz extension at wrist
is essential for stretching prior to flexion of digits)

100. 100
WRIST DROP
unopposed
action of flexors
at wrist and
elbow.

101. 101
WRIST DROP
unopposed
action of
flexors at
wrist and
elbow.

102. 102
RADIAL NERVE : APPLIED
b) Sensory
– Loss of sensation over
• posterior surface of arm, forearm and
• lower lateral surface of arm
– Hand – dorsum lateral part
– Digits – lateral 31/2 digits upto nail beds, dorsal
surface

103. 103
Sensory loss in radial nerve injury

104. 104
RADIAL NERVE : APPLIED
2. Injury of N in Spiral groove
• Causes
– Fracture of middle shaft of humerus
– Pressure on Nerve – Saturday Night palsy
– Operating table edge
– Prolonged use of tourniquet
a) Motor
– Triceps not affected, WHY ???
• Extension of elbow not impaired
– WRIST DROP
b) Sensory
– Back of forearm,
– dorsum of hand- lateral part
– Digits – lateral 31/2 upto nailbed

105. 105
RADIAL NERVE : APPLIED
3. Injury to Deep br – Posterior interosseous N
• Causes
– Fracture of upper radius
– Dislocation of head of radius
– Penetrating wound of upper forearm
• Motor
– Brachioradialis, ECRL escapes injury.
– Other extensors paralyzed
– Effect at wrist :
• Extension possible but with radial deviation
• ( be’coz ECRL escapes injury, ECU, ECRB paralyzed)
• No sensory loss
– (Deep br purely motor)

106. 106
RADIAL NERVE : APPLIED
4. Injury at Superficial br
• Superficial br superficially present on wrist
• Causes
– Compression by
• Tight bracelets, watch straps, plaster casts, hand cuffs etc
a) No motor loss
b) Sensory loss
– Hand – dorsum lateral ½
– Digits – dorsum lateral 31/2 up to nail beds
– Sensory loss may be minimal and may present only on dorsum of knuckle
of index finger
Summary
– If triceps paralyzed – injury at axilla
– BR paralyzed with normal triceps – injury at radial groove
– If BR and triceps both normal – injury beyond lateral epicondyle

107. THANK YOU