The Hip - book
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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.