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Extensor carpi ulnaris



Extensor carpi ulnaris - posterior view
Extensor carpi ulnaris - anterior view
Extensor carpi ulnaris - medial view

General information

  • This section is strictly limited to anatomy, you might be looking for clinical relevant information which is found under the clinical chapters -- muscles section, click here to go to that page
  • Is a part of the lower arms superficial posterior muscle group


  • Superficial


  • Lateral epicondylus humerus
  • Posterior limitation of ulna


  • Basis 5. metacarpal, posterior

Main function

  • Wrist
    • Extension
    • Ulnar deviation

Secondary function

  • Elbow
    • Extension

Nerve innervation

  • Segmental
    • C7-C8
  • Peripheral
    • Radial nerve

Arterial supply

  • Posterior interosseus artery


  • Patient position
    • Sitting or supine
  • Place your hand just posteriorly on the ulna and feel for the muscle
  • Ask the patient to perform extension and ulnar deviation of the hand while you feel for the contraction

Strength test

  • Patient position
    • Sitting or supine
  • Ask the patient to hold the lower arm in full pronation
  • Give resistance towards the dorsal side of the hand at the 5.metacarpal in a flexion and radial deviation direction, so that the patient is giving force towards extension and ulnar deviation