Musculus obturator externus
The obturator externus originates from the external surface of the obturator foramen and surrounding bone and inserts into the trochanteric fossa of the femur. Its actions are to laterally rotate the femur and stabilize the hip joint. It is innervated by the obturator nerve (roughly L4-L6). It is part of the deep hip rotator group.
Origin: External surface of the obturator foramen and surrounding bone
Insertion: Trochanteric fossa of the femur
Action: Laterally rotates the femur; stabilizes the hip
Innervation: Obturator nerve (L4-L6)
Isolated injury is uncommon. Relevant in evaluations of hip stability or after pelvic trauma. The obturator nerve can be affected in pelvic fractures or prolonged recumbency.
## Overview Deep hip pathology encompasses disease or injury affecting the coxofemoral joint or surrounding deep structures that is not readily apparent on routine examination. It may include osteoar
Hind-limb weakness or abnormal hip posture after trauma or anesthesia should be evaluated.
## Overview Deep hip pathology encompasses disease or injury affecting the coxofemoral joint or surrounding deep structures that is not readily apparent on routine examination. It may include osteoarthritis, ligament injury, or fracture-related damage and typically produces deep-seated hind-limb lameness. ## Causes Trauma, developmental disease, or degenerative change. Often part of a larger pelvic injury complex. ## Diagnosis Lameness examination, manipulation, radiographs, and advanced imaging (ultrasound, scintigraphy, or computed tomography). Intra-articular analgesia can help localize pain. ## Treatment Depends on the specific lesion: rest and anti-inflammatories for mild osteoarthritis; surgical options are limited for most deep hip injuries in adult horses. ## Recovery and Prognosis Guarded for significant pathology. Many horses are managed for comfort rather than return to high-level work. ## Prevention Trauma avoidance. Signs include: deep-seated hind-limb lameness; abnormal limb rotation; pain on deep hip manipulation; imaging abnormalities
Isolated injury is uncommon. Relevant in evaluations of hip stability or after pelvic trauma. The obturator nerve can be affected in pelvic fractures or prolonged recumbency.
Hind-limb weakness or abnormal hip posture after trauma or anesthesia should be evaluated.
See the Obturator Externus on our interactive 3D horse model. Open 3D Model