Which nerve provides innervation to obturator externus?

Which nerve provides innervation to obturator externus?

• A. Anterior division obturator nerve
• B. Tibial nerve
• C. Common fibular nerve
• D. Posterior division obturator nerve

Answer: (D)

Obturator externus is supplied by the obturator nerve, specifically its posterior division. As the obturator nerve traverses the pelvis and splits into anterior and posterior divisions, the posterior division gives off the muscular branch to obturator externus (and the hamstring part of adductor magnus). The anterior division supplies other thigh adductors like adductor longus, adductor brevis, gracilis, and sometimes pectineus, but not obturator externus. The tibial and common fibular nerves are branches of the sciatic nerve and do not innervate this muscle.

Obturator externus is supplied by the obturator nerve, specifically its posterior division. As the obturator nerve traverses the pelvis and splits into anterior and posterior divisions, the posterior division gives off the muscular branch to obturator externus (and the hamstring part of adductor magnus). The anterior division supplies other thigh adductors like adductor longus, adductor brevis, gracilis, and sometimes pectineus, but not obturator externus. The tibial and common fibular nerves are branches of the sciatic nerve and do not innervate this muscle.