Skip to content

Extensor carpi radialis brevis



Extensor carpi radialis brevis - posterior view
Extensor carpi radialis brevis - anterolateral view
Extensor carpi radialis brevis - lateral view


General remarks

  • 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 radial muscle group
  • Is the smallest of the lower arms three radial muscles


  • Superficial


  • Lateral epicondyle humerus
  • Fascia antebrachii


  • 3. metacarpal, posterior

Main function

  • Wrist
    • Extension
    • Radial deviation

Secondary function

  • Elbow
    • Flexion

Nerve innervation

  • Segmental
    • C6-C8
  • Peripheral
    • Radial nerve

Arterial supply

  • Brachial artery
  • Radial artery

Palpation muscle belly

  • Patient position
    • Sitting or supine
  • Identify brachioradialis, extensor carpi radialis longus and extensor carpi radialis brevis by squeezing them between your index finger and thumb
  • Squeeze these 3 muscles and pull them out somewhat away from the lower arm, the fingers are on the posterior part of the group at the extensor carpi radialis brevis
  • Ask the patient to perform an extension and radial deviation movement of the hand while you feel for the contraction in the tendon

Palpation, distal tendon

  • Patient position
    • Sitting or supine
  • Ask the patient to make a fist while he/she is holding the wrist in a neutral position
  • Feel for the tendon at it's insertion at the 3.metacarpal posteriorly at the hand

Strength test

  • Patient position
    • Sitting
  •  Ask the patient to lean forward on the chair so that he is sitting bent forward with his upper body and the elbow is in flexion while it rests on the treatment bench or table, the lower arm is held in almost full pronation
  • Give resistance towards the dorsal part of the hand approximately at the 2-3 metacarpal in the direction of flexion against the ulnar side so that the patient is giving counterforce towards extension and radial deviation
  • Ask the patient to maintain the hand's position while you give resistance