Anatomy Ventral rami from T12-S3 Found on the anterior surface of the quadratus lumborum and lies posterior to the psoas muscle Sciatic nerve composed of L4-S3 peroneal division more lateral than the tibial division NAVAL: within the triangle, from a lateral to medial direction, are the femoral Nerve, Artery, and Vein, and the Lymphatic vessels POP'S IQ: nerves exiting below piriformis are : Pudendal, Obturator internus, Postfemoral cutaneous, Sciatic, Inferior gluteal, Quadratus femoris L5 nerve root endangered during percutaneous iliosacral screw placement Name Nerves Muscles Supplied Superior gluteal L4-S1 Gluteus medius and minimus/tensor fascia lata Quadratus femoris L4-S1 Quadratus femoris/inferior gemellus Peroneal L4-S2 Biceps (short head)/tibialis anterior/extensor digitorum longus/peroneus tertius/extensor hallucis longus; peroneus longus and brevis/extensor hallucis brevis/extensor digitorum brevis Tibial L4-S3 Semimembranosus/semitendinosus/biceps (long head)/adductor magnus/gastrocnemius/soleus/plantaris/popliteus/tibialis posterior/flexor digitorum longus/flexor hallucis longus Obturator internus L5-S2 Obturatorius internus/superior gemellus Inferior gluteal L5-S2 Gluteus maximus Posterior femoral cutaneous S1-S3 Sensory: posterior thigh