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  • Deep


  • The origin of the tendons of flexor digitorum profundus at the level of the metacarapal bones
    • Passes the flexor sides of MCP-joints and at the base of the fingers radial sides they pass over to the dorsal aponeurosis


  • The muscle attaches to the tendons of extensor digitorum at the level of the proximal phalanx, at the radial side of 2-5 finger

Main function

  • 2.-5. finger IP
    • Extension
  • 2.-5. finger MCP
    • Flexion

Nerve innervation

  • Segmental
    • C8-Th1
  • Peripheral
    • Median nerve
    • Ulnar nerve

Arterial supply

  • Radial artery
  • Ulnar artery


  • Patient position
    • Sitting or supine
  • Place the fingers on the lateral side and the anterior aspect of the little finger's metacarpal
  • Ask the patient to flex the little finger at the MCP while the IP-joints are extended
  • Feel for the contraction while the patient performs the movement
  • Do the same for the 2-4 fingers

Strength test

  • Patient position
    • Sitting or supine
  • Fixate the hand in some degree of extension
  • Ask the patient to hold the fingers extended for the IP-joints while the MCP-joints are flexed
  • Give resistance towards the dorsal aspect of the middle and distal phalanx in the direction of flexion, so that the patient is giving force twards extension
  • Then perform resistance towards the palmar surface of the proximal phalanges towards extension, so that the patient is giving force towards flexion
  • It is important to note that these two steps are done seperately, and not in the same movement