Root Value
C5, C6, C7, C8 AND T1
FROM
Posterior Cord
TO
Posterior Interosseous Nerve
MUSCLE INNERVATION
Posterior Compartment of Arm and Forearm
COMMON SITES AND CAUSES
Injury to Radial Nerve at different levels causes different syndromes with varying motor and sensory deficits.
AXILLA
(1) Saturday night palsy
(2) Crutch Palsy
Motor deficit
Loss of extension of forearm, weakness of supination, and loss of extension of hand and fingers.
Presence of Wrist Drop, inability to extend the hand and fingers.
Sensory deficit
Loss of sensation in lateral arm, posterior forearm, the radial half of hand, and dorsal aspect of radial three and a half digits.
ARM
(1) Mid-Shaft Humerus Fracture
(2) Holstein-Lewis Fracture
Motor deficit
Weakness of supination
Loss of extension of hand and fingers
Presence of wrist drop , inability to extend the hand and fingers.
Sensory deficit
Loss of sensation in posterior forearm, the radial half dorsum of hand, and dorsal part of radial three and half digits.
Elbow
(1) Neck of radius fracture
(2) Elbow dislocation or fracture
(3) Pressure due to tight cast
(4) Rheumatoid nodules
(5) Injections due to tennis elbow
Deep branch of the radial nerve injury piercing the radial head causing Posterior Interosseous Nerve (PIN) syndrome
Motor deficit
Weakness in extension of hand and loss of extension of fingers
Presence of finger drop, and partial wrist drop
Sensory deficit
None, as sensation is supplied by the superficial radial nerve
Distal forearm:
Wartenberg Syndrome
Motor deficit
None
Sensory deficit
Numbness and tingling in radial half of dorsum of hand, and dorsal aspect of radial three and half digits
In Wartenberg’s Syndrome , there is typical radial wrist pain, Finkelstein’s test may be positive
SPECIAL TESTS
RADIAL NERVE TEST
Upper Limb Neurodynamic Test for Radial Nerve
EMG AND NERVE CONDUCTION STUDIES
Wrist Drop Test
Patient should be seated well during the procedure.
The patient should adopt a praying position with the hands and palms together.
The patient pulls the palm apart.The patient holds hands for about 15 cm apart for a minute.
He should maintain wrist extension till one minute.
The examiner takes note of poor range of motion or the inability to hold wrist in extension.
A positive Wrist Drop Test is the presence of weakness and the inability of a patient to maintain this position of the upper limb