BY: Azmat Ali Khan
Ulnar nerve is one of the major 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 thorasic nerve, so the root
value of ulnar nerve is C8 and T1.These
(C8,T1) coordinate to form the lower trunk of
Course From Cord to Axilla.
The Ulnar nerve runs between the Axillary
artery and vein in the axilla.
Course from Axilla to Arm
From the axilla it enters in the arm and stays
between the brachial artery and vein.
The nerve runs inferior and posterior medial
portion of humerus bone till it enters the
As the ulnar nerve exists the cubital tunnel, it
courses between the two head of the flexor
Carpi ulnaris and enters the anterior
compartment of the forearm.
Shortly after exiting the cubital tunnel, the
ulnar nerve gives off motor branches to the
flexor Carpi ulnaris.
It then lies on the anterior surface of the
flexor digitorum profundus.
In the middle of the forearm at approximately
12 cm distal to the medial epicondyle, the
ulnar nerve becomes the superficial and
meets with the ulnar artery as it travels
toward the wirst.
The nerve then descends through the medial
forearm, giving off no further muscular
branches untill after the wrist.
Five to eight centimeters proximal to the
wrist, the dorsal ulnar sensory branch exits to
supply sensation to the dorsal medial hand
and dorsal fifth and medial fourth digits.
At the level of the ulnar styloid, the palmar
cutaneous sensory branch originates to
supply sensation to the proximal medial
Near the wrist the ulnar nerve rises superficial
to the flexor carpi retinaculum and lies under
the tendon of the flexor carpi ulnaris before
its attachment to the pisiform.
The ulnar nerve the turns radial to the
pisiform to lies in a tunnel known as Guyon’s
canal within the canal, the ulnar nerve divides
into motor and sensory branches.
Ulnar motor response: ulnar motor study
recording abductor digiti minimi
(ADQ)stimulating wrist, below elbow and
above elbow in the flexed elbow position.
Ulnar F response
Ulnar sensory response: recording medial half
of ring finger, ulnar F5, dorsal cutaneous
Motor normative data:
Sensory normative data:
Latency ms Amplitude
3.5 2 35-40
C v ms F latency ms
3.3 5 53.6 32.0
Contra lateral difference
1.4> 0.7 >
Peak lat difference (ms)
Ulnar palmer (ms)
2.2> 0.4 >
The best thing about the future is that it
comes one day at a time.
By Abraham Lincoln.