Khairul Nizam bin Abdul Rahman
◦ Ulnar Nerve is one of the terminal branches of brachial plexus.
◦ It is the continuation of medial cord of brachial plexus which arises from the anterior
division of the lower trunk.
◦ The fibers of ulnar nerve arise from the eight cervical and first thoracic nerve, so the
root value of ulnar nerve is C8 and T1. These (C8,T1) coordinate to form the lower trunk
of brachial plexus.
Origin of the Ulnar Nerve
◦ The ulnar nerve originates from the C8-T1 nerve roots (and occasionally carries C7
fibres) which form part of the medial cord of the brachial plexus.
In the Axilla
◦ It descends on the medial side of the 3rd part of axillary artery between it and axillary
In the Arm
◦ It descends on the medial side of brachial
artery down to the insertion of
coracobrachialis muscle, Pierces the
medial intermuscular septum at the arcade
of Struthers ~ 8cm from medial epicondyle
and lies with triceps. Travels on back of
At the Elbow
◦ It reaches the back of med.epicondyle
to enter the forearm between 2 heads
of flexor carpi ulnaris(and here it is
accompanied by sup.ulnar collateral
a. and post. branch of inferior ulnar
In the Forearm
◦ After passing between 2 heads of
flexor carpi ulnaris, it descends
vertically infront of med. side of flexor
digitorm profunds covered by the
flexor carpi ulnaris.
In the Hand
◦ It enters the palm of the hand by passing in front of med. part of flexor retinaculum
between pisiform(medially) and the ulnar artery(laterally)& finally ends by dividing into
superficial and deep branches.
◦ The ulnar nerve is responsible for the pain, or 'funny bone', sensation that occurs if the
elbow bone is suddenly struck.
◦ Continual pressure on the elbow or inner forearm may cause damage. Injury can also
occur from elbow fractures or dislocations.
◦ Damage to the ulnar nerve causes problems with sensation and mobility in the wrist
and the hand.
◦ In a patient with ulnar nerve damage, some of the fingers may become locked into a
flexed position. This is sometimes nicknamed "claw hand.
◦ " Wrist movement is also often observed to be weaker with damaged ulnar nerves.
Ulnar Nerve Entrapment
◦ The Ulnar Nerve can become pinched in
different locations .
◦ 1- Thoracic outlet syndrome .
◦ 2-cubital tunnel syndrome .
◦ 3-Ulnar Tunnel syndrome .
Classification of nerve injuries
Mainly the type of nerve trauma depends on the mechanism of injury:
Common sites of ulnar nerve injury
The ulnar nerve is most commonly injured
◦ At the elbow, where it lies behind the medial epicondyle. The injuries at the elbow are
usually associated with fractures of the medial epicondyle.
◦ At the wrist, where it lies with the ulnar artery in front of the flexor retinaculum. The
superficial position of the nerve at the wrist makes it vulnerable to damage from cuts
and stab wounds.
Ulnar Nerve injuries at elbow
Cubital Tunnel Syndrome
◦ Causes of Ulnar Nerve entrapment around the cubital tunnel :
1.Cubitus Valgus :
Deformity in which the elbow is turned outward
A spur on the Medial Epicondyle
◦ The flexor carpi ulnaris and the medial half of the flexor digitorum profundus muscles
◦ The paralysis of the flexor carpi ulnaris can be observed by asking the patient to make
a tightly clenched fist.
◦ Normally, the synergistic action of the flexor carpi ulnaris tendon can be observed as it
passes to the pisiform bone; the tightening of the tendon will be absent if the muscle is
◦ The profundus tendons to the ring and little fingers will be functionless,
◦ The terminal phalanges of these fingers are therefore not capable of being markedly
◦ Flexion of the wrist joint will result in abduction, owing to paralysis of the flexor carpi
◦ The medial border of the front of the forearm will show flattening owing to the wasting
of the underlying ulnaris and profundus muscles.
◦ The small muscles of the hand will be paralyzed, except the muscles of the thenar
eminence and the first two lumbricals, which are supplied by the median nerve.
◦ The patient is unable to adduct and abduct the fingers and consequently is unable to
grip a piece of paper placed between the fingers.
◦ It is impossible to adduct the thumb because the adductor pollicis muscle is paralyzed.
◦ If the patient is asked to grip a piece of paper between the thumb and the index
finger, he or she does so by strongly contracting the flexor pollicis longus and flexing the
terminal phalanx (Froment's sign).
◦ The metacarpophalangeal joints become hyperextended because of the paralysis of
the lumbrical and interosseous muscles, which normally flex these joints.
◦ The interphalangeal joints are flexed, owing again to the paralysis of the lumbrical and
interosseous muscles, which normally extend these joints through the extensor
◦ The flexion deformity at the interphalangeal joints of the fourth and fifth fingers is
obvious because the first and second lumbrical muscles of the index and middle
fingers are not paralyzed.
◦ In long-standing cases the hand assumes the characteristic claw deformity (main en
◦ Wasting of the paralyzed muscles results in flattening of the hypothenar eminence and
loss of the convex curve to the medial border of the hand.
◦ Examination of the dorsum of the hand will show hollowing between the metacarpal
bones caused by wasting of the dorsal interosseous muscles.
◦ Loss of skin sensation will be observed over the anterior and posterior surfaces of the
medial third of the hand and the medial one and a half fingers.
◦ The skin areas involved in sensory loss are warmer and drier than normal because of the
arteriolar dilatation and absence of sweating resulting from loss of sympathetic control
Ulnar Nerve injuries at wrist
Guyon’s Canal Syndrome
◦ Sometimes called Guyon's tunnel syndrome
◦ Is a common nerve compression affecting the
ulnar nerve as it passes through a tunnel in the
wrist called Guyon's canal.
◦ The small muscles of the hand will be paralyzed and show wasting, except for the
muscles of the thenar eminence and the first two lumbricals.
◦ The clawhand is much more obvious in wrist lesions because the flexor digitorum
profundus muscle is not paralyzed, and marked flexion of the terminal phalanges
◦ The main ulnar nerve and its palmar cutaneous branch are usually severed
◦ The sensory loss will therefore be confined to the palmar surface of the medial third of
the hand and the medial one and a half fingers and to the dorsal aspects of the
middle and distal phalanges of the same fingers.
Vasomotor and trophic changes:
◦ These are the same as those described for injuries at the elbow. It is important to
remember that with ulnar nerve injuries, the higher the lesion, the less obvious the
clawing deformity of the hand.
Non-steroidal anti-inflammatory medicines
◦ Such as ibuprofen to help reduce swelling around the nerve.
◦ Like cortisone are very effective anti-inflammatory medicines.
Cubital tunnel release
◦ In this operation, the ligament ‘roof’ of cubital tunnels is cut and divided. This increases
the size of the tunnel and decrease pressure on nerve.
Ulnar nerve anterior transposition
◦ Moving the nerve to the front of medial epicondyle to prevents it from getting caught
on bony ridge and stretching when bends the elbow.
◦ Another options to release the nerve is to remove part of medial epicondyle.
Bracing or splinting
◦ To keep the elbow straight in position at night.
Nerve gliding exercises
◦ Helps the ulnar nerve slide through the cubital tunnel at the elbow and the Guyon’s
canal at the wrist.
◦ Also helps the arm and wrist from getting stiff.