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Abductor pollicis longus




Abductor pollicis longus - posterior view
Abductor pollicis longus - lateral view
Abductor pollicis longus - posterior zoom

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


  • Deep


  • Middle 1/3 of radius (posteriorly)
  • Middle 1/3 of ulna (posteriorly)
  • Middle 1/3 of membrana interossues


  • Base of 1.metacarpal (radial side)

Main function

  • Thumb - CMC
    • Abduction

Secondary function

  • RU-joint
    • Supination
  • Wrist
    • Radial deviation
    • Flexion
  • Thumb - CMC
    • Extension
    • Lateral rotation

Nerve innervation

  • Segmental
    • C6-C8
  • Peripheral
    •  Nervus radialis

Arterial supply

  • Posterior interosseus artery
  • Anterior interosseus artery


  • Pasient position: Sitting
  • Ask the patient to hold the radioulnar joint in a neutral position between pronation and supination
  • Place your hand on the lateral aspect of the wrist of the patient
  • Ask the patient to abduct and extend the thumb while you feel for the tendon of abductor pollicis longus and extensor pollicis brevis
  • Palpate along the muscle in a distal direction until you find the insertion of the 1.metacarpal.
  • At this position you can seperate the two tendons with a finger nail, the most anterolateral part of these is the abductor pollicis longus

Strength test

  • Patient position: Sitting or supine
  • Stabilize the patient's wrist
  • Ask the patient to hold the thumb in an abducted and extended position
  • Give resistance towards the lateral and distal side of the 1.metacarpal in the direction of adduction and flexion, so that the patient is giving force towards abduction and extension