Radial nerve

Dr Henry Knipe et al.

The radial nerve is one of five main branches of the brachial plexus. It provides motor and sensory innervation to the arm and forearm and sensory innervation to the hand. 

Origin

The radial nerve is one of two terminal branches of the posterior cord of the brachial plexus. It receives contributions from C5-T1 nerve roots.

Course

The radial nerve lies posterior to the axillary artery in the axilla and enters the posterior compartment of the arm under teres major muscle

In the posterior compartment of the arm, it winds it way around the spiral groove of the humerus, accompanying profunda brachii artery. It pierces the lateral intermuscular septum to enter the anterior compartment of the arm, then passes to the forearm by coursing anterior to the lateral epicondyle at the level of the elbow joint. It enters the cubital fossa, where it divides into superficial and deep branches. 

The superficial branch courses towards the wrist lateral to the radial artery and enters the hand, dividing into the dorsal digital cutaneous branches. 

The deep branch gives off the posterior interosseous nerve, which passes between the heads of the supinator muscle to enter the posterior compartment of the forearm and terminates at the level of the wrist joint. 

Branches and supply
  • muscular twigs in the arm: triceps brachii and anconeus muscles
  • superficial branch of the radial nerve: supplies cutaneous sensation to the dorsal aspect of the hand, dorsal aspect of the first to third digits and the dorsal lateral aspect of the fourth finger
  • deep branch of the radial nerve
    • posterior interosseous nerve: extensor muscles in the forearm as well as brachioradialis
  • articular twigs to the elbow and wrist joints

Radial nerve pathology is complex and can occur at any level (axillary, spiral groove, radial tunnel, posterior interosseous, superficial radial):


Upper limb anatomy
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Article Information

rID: 24691
Section: Anatomy
Tags: refs, cases
Synonyms or Alternate Spellings:

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Cases and Figures

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    Figure 1: radial nerve
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    Figure 2: brachial plexus
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    Figure 3: at the axilla
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    The radial nerve ...
    Figure 4: in the spiral groove
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    The lateral inter...
    Figure 5: lateral intermuscular septum
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