superficial forearm extensors

• Extensor Carpi Radialis Longus:

  O: Lower 1/3 lateral supracondylar ridge

  Adjacent intermuscular septum

  R: Distally

  I: Posterior aspect of base of 2nd MC

  A: Wrist extension and radial deviation

  NS: Radial nerve (C5,6,7,8, T1)
• Extensor Carpi Radialis Brevis:

  O: Common Extensor Origin (CEO) (lateral epicondyle of humerus)

  R: Distally (together with ECRL)

  I: Posterior aspect of base of 3rd MC

  A: Wrist extension and radial deviation

  NS: Posterior interosseous branch of radial nerve (C5,6,7,8,T1)
• Extensor Digitorum:

  O: CEO

  R: Four tendons run distally and pass deep to extensor retinaculum

  I: Extensor hood (DDE) on dorsum of medial four fingers

  A: Extension of MCP and wrist joints.

  May contribute to extension of IP joints

  NS: Posterior interosseous branch of radial nerve (C5,6,7,8,T1)
• Extensor Digiti Minimi:

  O: CEO

  R: Distally and medially

  I: Medial side of extensor hood of 5th finger

  A: Extension of 5th finger (all joints)

  Weak extension of the wrist

  NS: Posterior interosseous branch of radial nerve (C5,6,7,8,T1)
• Extensor Carpi Ulnaris:

  O: CEO and posterior border of ulna

  R: Distally and then tendon runs in a groove between head of ulna and its styloid process

  I: Tubercle on medial side of base of 5th MC

  A: Extension and ulnar deviation of wrist

  NS: Posterior interosseous branch of radial nerve (C5,6,7,8,T1)