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Deep Layer of Anterior Forearm - Details

Notes

Deep Layer of Anterior Forearm - Details

Pronator quadratus

  • Originates on the distal ulna (specifically, the anteromedial aspect)
  • Inserts on the distal radius (on the anterolateral aspect)
  • Pronates the forearm (turns the palms face down).

Flexor digitorum profundus

  • Originates on the ulna and the interosseous membrane
  • Inserts on distal phalanges of digits 2-5.
  • Flexes digits 2-5 at the distal phalanges and metacarpophalangeal joints and also the wrist (which the tendons cross).

Flexor pollicis longus

  • Originates on the radius and the interosseous membrane.
  • Inserts on the distal phalanx of digit 1.
  • Flexes digit 1 at the distal phalanges and metacarpophalangeal joints and also the wrist (which the tendons cross).

Flexor digitorum superficialis

  • Originates on the medial epicondyle of the humerus, the coronoid process of the ulna, and the radius (specifically, from the oblique line)
  • Inserts, via split tendons, to the middle phalanges of digits 2-5.
  • Flexes middle phalanges and metacarpophalangeal joints of digits 2-5 and the carpals.

Additional Information:

  • The flexor retinaculum is a band of connective tissue that forms the "carpal tunnel"; it holds the muscles and neurovascular structures in place.
  • The median nerve which supplies several muscles in the anterior forearm and hand, runs between flexor digitorum superficialis and flexor digitorum profundus.