Musculus pronator teres
A vestigial muscle in horses since they cannot pronate or supinate the forearm (the radius and ulna are fused). Small and functionally insignificant compared to other species.
Origin: Medial epicondyle of the humerus
Insertion: Medial border of the radius
Action: Vestigial; minimal functional significance in horses (cannot pronate the fused radius/ulna)
Innervation: Median nerve (C8-T1)
The origin region can be involved in medial elbow pain syndromes, though this muscle rarely causes clinical issues on its own.
The origin region can be involved in medial elbow pain syndromes, though this muscle rarely causes clinical issues on its own. Signs include: Deep medial elbow pain; lameness on palpation of the medial epicondyle; usually part of a broader elbow pathology.
See the Pronator Teres on our interactive 3D horse model. Open 3D Model