Premium
Neuromuscular partitioning in the extensor carpi radialis longus and brevis based on intramuscular nerve distribution patterns: A three‐dimensional modeling study
Author(s) -
Ravichandiran Mayoorendra,
Ravichandiran Nisanthini,
Ravichandiran Kajeandra,
Mckee Nancy H.,
Richardson Denyse,
Oliver Michele,
Agur Anne M.
Publication year - 2012
Publication title -
clinical anatomy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 71
eISSN - 1098-2353
pISSN - 0897-3806
DOI - 10.1002/ca.21246
Subject(s) - medicine , anatomy , muscle belly , tendon
Differential activation of specific regions within a skeletal muscle has been linked to the presence of neuromuscular compartments. However, few studies have investigated the extra‐ or intramuscular innervation throughout the muscle volume of extensor carpi radialis longus (ECRL) and brevis (ECRB). The aim of this study was to determine the presence of neuromuscular partitions in ECRL and ECRB based on the extra‐ and intramuscular innervation using three‐dimensional modeling. The extra‐ and intramuscular nerve distribution was digitized and reconstructed in 3D in all the muscle volumes using Autodesk Maya in seven formalin embalmed cadaveric specimens (mean age, 75.7 ± 15.2 years). The intramuscular nerve distribution was modeled in all the muscle volumes. ECRL was found to have two neuromuscular compartments, superficial and deep. One branch from the radial nerve proper was found to innervate ECRL. This branch was divided into anterior and posterior branches to the superficial and deep compartments, respectively. Five innervation patterns were identified in ECRB with partitioning of the muscle belly into two, three, or four compartments, in a proximal to distal direction depending on the number of nerve branches entering the muscle belly. The ECRL and ECRB both demonstrated neuromuscular compartmentalization based on intramuscular innervation. According to the partitioning hypothesis, a muscle may be differentially activated depending on the required function of the muscle, thus allowing multifunctional muscles to contribute to a variety of movements. Therefore, the increased number of neuromuscular partitions in ECRB when compared with ECRL could be due to the need for more differential recruitment in the ECRB depending on force requirements. Clin. Anat. 25:366–372, 2012. © 2011Wiley Periodicals, Inc.