Extensor Pollicis Brevis     


- Anatomy:
   - extensor tunnel I
   - origin:
        - posterior side at the distal end of the body of both the ulna and radius near their middle;
   - insertion:
        - posterior surface of the base of the proximal phalanx of thumb;
   - action:
        - extends proximal phalanx of the thumb; continued action extends and assists abduction of the 1st metacarpal;
   - synergists:  APL, EPL;
   - nerve:: PIN branch of deep radial nerve, C6, C7;

- Discussion:
    - annular ligament that restrains abductor pollicis longus & EPB over
          radius is directly over radial tubercle;
    - this area may be involved in DeQuervain's tenosynovitis



  A simplified technique to correct hyperextension deformity of the metacarpophalangeal joint of the thumb.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, May 17, 2012 8:48 am