- Anatomy:
- 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.
