Median Sensory Nerve - Recording the ring finger (antidromic)

Last updated on Tuesday, October 6 2009 by blondarb

Origin: C7 roots, middle trunk and lateral cord of the brachial plexus.

Recording Site: Ring Finger

Reference Site: Ring Finger

Ground: Palm or top of hand

Stimulation Site: Wrist

Procedure: The recording electrode is placed on the proximal phalanx of the ring finger. The reference electrode is placed on the middle phalanx of the ring finger. A distance of 13 cm is measured from G1 to the distal wrist crease over the median nerve. The nerve is stimulated at the wrist, proximal to the wrist crease and between the flexor carpi radialis and palmaris longus tendons. The nerve can also be stimulated at the elbow, above the elbow crease, medial to the pulse or biceps tendon. The nerve can also be stimulated at the elbow (above the elbow crease, medial to the brachial artery pulse or biceps tendon).

The same distance should be used when using the median ring finger study as a comparison study to the ulnar ring finger study. This study can also be performed orthodromically.

Related images:

Median Sensory Nerve - Ring Finger (antidromic)
This cartoon shows the placement for the recording and stimulating electrodes for this study.

Superfical nerves of the hand.
This image shows the superficial nerve anatomy of the hand

Deep anatomy of the right hand
This image shows the deep median and ulnar nerve anatomy of the hand

Median Sensory Nerve - Recording the ring finger (antidromic)
This photograph illustrates the technique for the median sensory study, recording from digit 4 (ring finger). Sensation to digit 4, in most people, is split between the median and ulnar nerves, making this useful in a comparison study looking for a median or ulnar mononeuropathy at the wrist.