The FrontalCortex question bank can help you study for the Residency Inservice Training Exam (RITE exam).

Extensor Pollicis Longus

Last updated on Monday, April 27 2009 by blondarb

peer review status unavailable
rating unavailable

Muscle Name: extensor pollicis longus

AKA:  musculus extensor pollicis longus

Abbreviation:  EPL

Spinal Nerve Roots:

Brachial Plexus Trunks:
    middle trunk
    lower trunk

Brachial Plexus Cords:
    posterior cord

Named Nerves:
    radial nerve

Proximal Attachment:  ulna  

Distal Attachment:  thumb, distal phalanx

Action:  extension of the thumb (metacarpophalangeal and interphalangeal)

Needle Insertion:  In the pronated forearm, midway between the styloid process and the lateral epicondyle, just lateral to the ulna bone and deep to the extensor indicis communis.

Activation for EMG:  Extend the thumb.

Pitfalls:  If the needle is placed to distal or close to the radial bone, the extensor pollicis brevis will be sampled.