Opponens Pollicis

Joe Muscolino

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The opponens pollicis intrinsic muscle of the hand. The transverse carpal ligament (flexor retinaculum) has been drawn in.

The Opponens Pollicis is a member of the Thenar Eminence Group of intrinsic muscles of the hand, composed of the:

 

ATTACHMENTS:

  • The opponens pollicis attaches from the transverse carpal ligament and the trapezium to the metacarpal of the thumb.
    • The transverse carpal ligament is also known as the flexor retinaculum.

 

ACTIONS:

  • Opposes the thumb at the carpometacarpal joint.
  • Abducts the thumb at the carpometacarpal joint.
  • Flexes the thumb at the carpometacarpal joint.
  • Medially rotates the thumb at the carpometacarpal joint.

 

NOTES:

  1. The opponens pollicis is the deepest of the thenar eminence muscles.
  2. Opposition of the thumb is an oblique-plane motion pattern that comprises three cardinal-plane joints actions: abduction, flexion, and medial rotation of the metacarpal of the thumb at the carpometacarpal (saddle) joint of the thumb.