Inner Pelvic Muscles - Horse Anatomy

The inner pelvic muscles are small and lie close to the coxofemoral (hip) joint. They run between the pelvis and trochanteric fossa of the femur.

Internal Obturator

In the horse this muscle has two heads, a small and tendinous pubic head and a larger pelvic head.

Innervation: Sciatic n.

Origin:

Pubic head - Cranial and medial borders of the obturator foramen

Pelvic head - Pelvic symphysis and pelvic aspect of the body of the ilium

Insertion: Trochanteric fossa together with the gemellus muscle, having passed over the lesser sciatic notch

Action: Rotates the femur laterally, aids hip extension

External Obturator

Innervation: Obturator n.

Origin: Vental surface of pelvis, close to the obturator foramen

Insertion: Trochanteric fossa

Action: Supinates the femur and adducts the limb

Gemellus

In the horse, these two small muscle bundles are fused and unite partly with the internal obturator muscle

Innervation: Sciatic n.

Origin: Ischium

Insertion: Trochanteric fossa

Action: Aids lateral rotation of the limb