M. obliquus externus abdominis, crus mediale
The medial crus of the superficial inguinal ring, formed by the aponeurosis of the external abdominal oblique. Together with the lateral crus, it frames the superficial inguinal ring through which the spermatic cord (in males) or round ligament (in mares) passes.
Origin: Aponeurosis of external abdominal oblique
Insertion: Prepubic tendon; symphyseal tendon
Action: Forms medial boundary of superficial inguinal ring; supports inguinal region
Innervation: Ventral branches of thoracic (T10–T18) and lumbar (L1–L3) spinal nerves
Strain or tearing of individual costal digitations of the external abdominal oblique, often from trauma (kicks) or sudden rotational movements. Common site for abdominal wall herniation in horses.
Strain or tearing of individual costal digitations of the external abdominal oblique, often from trauma (kicks) or sudden rotational movements. Common site for abdominal wall herniation in horses. Signs include: Localized swelling over the affected rib; pain on palpation; reluctance to bend laterally; may develop into a hernia if multiple digitations are disrupted.
See the External Abdominal Oblique - Pelvic Tendon (Crus Mediale) on our interactive 3D horse model. Open 3D Model