This is one of the first things I look for when people come to me with sciatic pain that goes down the leg.
🔈 RELATIONSHIP OF SCIATIC NERVE TO PIRIFORMIS
(A) The sciatic nerve usually emerges from the greater sciatic foramen inferior to the piriformis.
(B) In 12.2% of 640 limbs studied by Dr. J. C. B. Grant, the sciatic nerve divided before exiting the greater sciatic foramen; the common fibular division (yellow) passed through the piriformis.
(C) In 0.5% of cases, the common fibular division passed superior to the muscles where it is especially vulnerable to injury during intragluteal injections.