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First Dorsal Interosseous

Last updated on Monday, April 27 2009 by blondarb

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Muscle Name: first dorsal interosseous


Abbreviation:  FDI

Spinal Nerve Roots:

Brachial Plexus Trunks:
    lower trunk

Brachial Plexus Cords:
    medial cord

Named Nerves:
    ulnar nerve

Proximal Attachment:  metacarpal bone.

Distal Attachment:  proximal phalanx on the first digit.

Action:  Abduct the first digit.

Needle Insertion:  With the hand in the midpoint between supination and pronation, the needline is inserted at the midpoint between the first and second metacarpal bone.

Activation for EMG:  Abduct the finger. ("Point to the ceiling")


Notes:  One of the least painful hand muscles to study.