L5.5.6.1.2: Posterior Forearm

• POSTERIOR FOREARM

  [a] Brachioradialis

  [b] Extensor Carpi Radialis Longus

  [c] Abductor Pollicis Longus

  [d] Extensor Pollicis Brevis

  [e] Extensor Digitorum

  [f] Extensor Carpi Ulnaris

  
• Extensor Carpi Radialis Longus

  ○ Partly overlapped by brachioradialis and these muscles often blend together

  ○ A wrist extensor

  ○ Can be palpated infero-posteriorly to the elbow
• Abductor Pollicis Longus

  ○ One of a deep extensor of the forearm

  ○ Responsible for facilitating movement and stabilization of the thumb

  ○ Tendon is present in the first extensor compartment of the wrist

  ○ Lies immediately below the supinator and sometimes unites with it

  ○ Muscle belly consists fundamentally of 3 parts which results in 2 divisions of tendons
• Extensor Pollicis Brevis

  ○ Short and slender muscle

  ○ Extends from the posterior surface of radius to the proximal phalanx of thumb
• Extensor Digitorum

  ○ Extends the medial 4 digits of the hand

  ○ Innervated by the posterior interosseous nerve, which is a branch of the radial nerve
• Extensor Carpi Ulnaris

  ○ Elongated fusiform muscle

  ○ Primarily functions to extend and adduct the wrist

  ○ Spans between the elbow and the base of the little finger