Extensor Pollicis Longus

The tendon of Extensor Pollicis Longus can be seen on the radial side of the wrist, at the base of the thumb where it forms the lower border of the 'anatomical snuffbox' a triangular shape between two tendons.

Origin

• Upper posterior surface of the ulna

Insertion

• Base of the distal phalanx of the thumb

Actions

• Extension of the wrist
  
  
• Extension of the thumb

Innervation

• Posterior interosseous nerve

Daily uses

• Releasing your grip on an object

Example Strengthening Exercises

• Wrist extension using a resistance band

Example Stretches

• Wrist extensor stretch

Related muscles

• Extensor carpi radialis brevis
  
  
• Extensor carpi radialis longus
  
  
• Extensor digitorum communis
  
  
• Extensor carpi ulnaris