This document summarizes the clinical examination of median nerve compressive neuropathies, including carpal tunnel syndrome, pronator syndrome, anterior interosseous nerve syndrome, and the ligament of Struthers. Key examination findings for each condition are described such as locations of pain, weakness, sensory deficits and positive provocation tests. Electrodiagnostic testing is recommended if surgery is being considered for carpal tunnel syndrome diagnosis.

1. Clinical Examination
in Compressive
Neuropathies of the
Median Nerve
Prepared by Dr MADAN MOHAN,
Consultant, Orthopaedics, KIMS Trivandrum

2. Origin and Course
• The medial and lateral cords of the brachial plexus with contributions
from C6,7,8 and T1
• In the upper arm, the course of the median nerve is in close proximity
to the brachial artery, both of which pass along the anterior aspect of
the intermuscular septum on the medial side of the arm
• The median nerve and brachial artery enter the antecubital fossa
medial to the biceps brachii and superficial to the brachialis muscle,
then course through three successive arches as they enter the
forearm.

3. The Three Arches……
• The first arch is formed by the bicipital aponeurosis (lacertus fibrosis)
as it connects the biceps brachii to the flexor-pronator mass and the
ulna. The median nerve is superficial to the brachialis tendon, but
deep to the bicipital aponeurosis.
• The two heads of the pronator teres (PT) muscle form the second
arch. The median nerve lies superficial to the ulnar head and deep to
the humeral head.
• Finally, the median nerve travels between the humeroulnar and radial
heads of the flexor digitorumsuperficialis (FDS) muscle, under the
thick fibrous structure between them, known as the sublimis ridge.

4. In the Forearm …..
• In the forearm, the median nerve runs along the radial side of the
flexor digitorum profundus (FDP), deep to the FDS.
• The anterior interosseus nerve (AIN) branches from the median nerve
in the proximal half of the forearm. Terminates deep to the pronator
quadratus (PQ) muscle
• At approximately five cm proximal to the wrist crease, the median
nerve emerges superficially between the flexor carpi radialis (FCR)
tendon radially and the palmaris longus (PL) tendon ulnarly

5. In the Forearm, Wrist and Hand …..
• The palmar cutaneous branch of the median nerve arises approximately
five cm proximal to the distal wrist crease and passes outside of the carpal
tunnel
• Once in the hand, the thenar motor branch (or recurrent motor branch)
emerges radially.
• The median nerve goes on to divide into radial and ulnar divisions in the
plane between the flexor tendons (deep), and the palmar arch
(superficially).
• The radial division splits to form the common digital nerve to the thumb
and the proper digital nerve to the radial half of the index finger.
• The ulnar division splits to form the common digital nerves of the second
and third web spaces

6. Physical Examination
• The median nerve innervates muscles involved in forearm
pronation, wrist flexion, flexion of the digits, and thumb
opposition and abduction
• The median nerve carries sensory innervation from the
radial aspect of the palm via the palmar cutaneous branch,
and the volar surfaces of the thumb, index, middle fingers,
and the radial half of the ring finger.
• This sensory information is essential for fine motor tasks.

7. The Ligament of Struthers
• Approximately 1% of people have an accessory
condyle or supracondylar spur approximately five cm
proximal to the medial epicondyle of the humerus.
• The ligament of Struthers attaches this bony
prominence proximally to the medial epicondyle
distally.
• The median nerve is susceptible to compression as it
passes underneath this ligament along with the
brachial artery

8. •The patient will often complain of a deep aching pain
in the proximal forearm with an insidious onset,
hand weakness, and numbness in the median-nerve
distribution.
•On examination, this pain is often exacerbated with
testing of the PT and FCR. Worsening of symptoms
often occurs with repetitive pronation and
supination
•Frequently, weakness of muscles innervated by the
AIN is most prominent.
•A Tinel sign may be present proximal to the medial
epicondyle.

9. Pronator Syndrome
• Results from compression of the median nerve as it passes between
the 2 heads of the PT
• The patient often complains of aching discomfort in the forearm,
weakness in the hand, and numbness in the thumb and index finger
• Tenderness on palpation of the PT muscle is a common finding.
• A Tinel sign may be present in the antecubital fossa
• The PT muscle receives its innervation proximal to the site of
compression, and therefore might be the only muscle innervated by
the median nerve spared in this syndrome

10. A provocative maneuver
to test for pronator
syndrome is to apply
direct pressure in the area
of the PT with the
patient’s forearm
supinated. It is considered
positive if paresthesia is
reported in the median
nerve distribution within
one minute of
compression

11. Pronator Syndrome ……..
•Phalen’s test may be positive in 50%
patients with pronator syndrome
•Unlike CTS, a history of nocturnal
pain and/or numbness is rare

12. The Sublimus Arch
•The next possible site of compression along the
course of the median nerve is the sublimis arch
formed between the two heads of the FDS.
• Again, clinical findings are similar to those in
pronator syndrome, although pain exacerbated by
strong flexion of the proximal interphalangeal joints
of the index, long, ring, and little fingers is
suggestive of compression at the sublimis arch
rather than at the PT

13. Anterior interosseous nerve syndrome
• Vague proximal forearm pain and progressive loss in their ability to do
tasks requiring fine motor control and pinch, such as handwriting
• The patient will have weakness in the FDP to the index and middle
fingers and weakness in the PQ.
• Deficits in the flexor pollicis longus (FPL) and index-finger FDP result
in the inability to form the “OK” sign
• Sensibility is normal, as the AIN does not contain sensory fibers to the
hand

14. Symptoms of AIN
syndrome can be
provoked with
resisted elbow
flexion, resisted
forearm pronation,
and resisted finger
flexion

15. Carpal Tunnel Syndrome
• Patients predominantly complain of numbness and/or paresthesia in
the median-nerve distribution, rather than pain.
• These symptoms are typically worse at night and are improved with
shaking of the hand, known as the flick sign
• A history of dropping objects correlates with weakness of the
opponens pollicis and abductor pollicis brevis muscles.
• Atrophy of these thenar muscles represents advanced disease

16. Phalen wrist flexion
test = Maximal flexion
of wrists by opposing
dorsal surfaces of
hands = Reproduction
or exacerbation of
paresthesia or
numbness in median
nerve distribution
within 60 s

17. Durkin carpal
compression test =
Exert direct pressure at
or just proximal to the
carpal tunnel =
Reproduction or
exacerbation of
paresthesia or
numbness
in the median nerve
distribution within 60 s

18. Tinel Sign
Light tapping over the median
nerve at the wrist = Reproduction
or exacerbation of paresthesia in
the median nerve distribution

19. Static 2-point
discrimination
testing
Two points of various
distance are applied with
just enough pressure for
patient to appreciate the
stimulus = Inability to
distinguish 2 points 5 mm
apart

20. Semmes-Weinstein
monofilament
testing
Monofilaments of varying
diameters are applied to
volar aspect of distal index
or middle finger until the
filament bends = Inability
to perceive a
monofilament sized 2.83
or less

21. Ten test
A score (1–10) is reported by the patient
comparing an area of abnormal light
touch sensibility in the median nerve
distribution to an area of similar
innervation density with intact light touch
sensibility = Ratio less than one between
abnormal (scored 1–9) vs normal area
(scored 10). Allows examiner to track
changes over time

22. • The highest-level recommendation made by the AAOS group is to
obtain electrodiagnostic testing if clinical evaluation is positive and
surgical management is being considered.
• This recommendation remains controversial, as some investigators
claim electrodiagnostic tests do not change the probability of
diagnosing CTS in patients who are considered to have CTS based on
their history and physical examination alone