Educational resource developed at the Veterinary Anatomy Section, ICAR-Indian Veterinary Research Institute (ICAR-IVRI), Bareilly.
📝 STANDARD DESCRIPTION:
Type: Intrinsic, Forearm (Accessory Extensor)
Origin: Lateral surface of radius
Insertion: Head of medial splint bone (Mc II) or proximal medial aspect of Mc III
Function: Extends carpus; stabilizes medial aspect.
📚 DETAILED DESCRIPTION:
THE MEDIAL CARPAL STABILIZER
Also known as Abductor Digiti I Longus (though digit I is absent), this smaller muscle runs obliquely across the dorsal carpus.
OBLIQUE COURSE: Originates from the lateral radius but courses mediodistally to insert on the medial splint bone (Mc II) or medial aspect of the cannon bone. This oblique line of pull provides medial stabilization to the carpus during extension.
FUNCTION: Assists in carpal extension but with medial vector component, preventing lateral drift of the carpus during loading. Also referenced as the 'medial collateral extensor.'
SURGICAL NOTE: Often encountered during dorsal approaches to the carpal joints; smaller than main ECR but distinct.
// COMPARATIVE ANALYSIS
| HORSE |
Similar; often called Abductor Digiti I Longus. |
| DOG |
True abductor of digit II when present. |
CLINICAL RELEVANCE
Carpal Sheath Tenosynovitis: Tendon lies within the same synovial sheath as ECR; disease processes involve both.
