Posterior superior iliac spine lliac crest Anterior superior iliac spine s Posterior superior iliac spine Median sacral crest Superior gluteal nerve spine s (Suprapiriform foramen) Greater Posterior inferior iliac spine sciatic (Infrapiriform foramen) Greater sciatic foramen Sciatic nerve nferior gluteal nerve Piriformis Pudendal nerve一 Sacrospinous ligament Greater trochanter Lesser sciatic foramen Posterior cutaneous nerve of thigh Ischial tuberosity [posterior femoral cutaneous nerve Sacrotuberous ligament schaal tuberosity Fig. 1337 Projection of skeleton and sciatic nerve onto the surface of the gluteal region posterior aspect. 梨状肌上、下孔 Suprapiriform and Infrapiriform Foramen梨状肌上、下孔 Suprapiriform and Infrapiriform Foramen 梨状肌 Piriformis 梨状肌上孔 梨状肌下孔