Motor Branch of Median Nerve



- Discussion:
    - most common pattern of motor branch of median nerve is extraligamentous take off from main branch of median nerve (distal to TCL in 50% pts)
    - in 30% of pts motor branch exits proximal to TLC;
    - in 20% of pts motor branch exits distal to TLC;
    - motor branch of median nerve in hand arises under or just distal to flexor retinaculum, & winds around distal border of retinaculum to reach thenar muscles and the lateral 2 lumbricals;
    - numerous variations in the branching have been described;
    - sensory branches innervate lateral three & 1/2 digits & palm of hand;
    - found at Kaplan's line which is intersection of line extending vertically from first web space and line formed from the radial origin of first web space connecting to hook of hamate



Transligamentous motor branch of the median nerve discovered during endoscopically assisted carpal tunnel release.

Anatomy of the thenar branch of the median nerve.

Correlation Between Muscle Morphology of the Transverse Carpal Ligament and Branching Pattern of the Motor Branch of Median Nerve

The thenar motor branch during carpal tunnel decompression: “the expert opinion” 

Variations in the course of the thenar motor branch of the median nerve and their relationship to the hypertrophic muscle overlying the transverse carpal ligament.

The Middle Finger Flexion Test to Locate the Thenar Motor Branch of the Median Nerve



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Monday, August 19, 2013 9:19 am