1 — Levator ani; 2 — Ischial tuberosity; 3 — Ischial spine; 4 — Sacrotuberous ligament; 5 — Coccyx [coccygeal vertebrae CoI-CoIV]; 6 — Sacrospinous ligament; 7 — Ischiococcygeus; Coccygeus; 8 — Piriformis; 9 — Sacrum [sacral vertebrae SI-SV]; 10 — Posterior superior iliac spine; 11 — Iliac crest; 12 — Anterior superior iliac spine; 13 — Anterior inferior iliac spine; 14 — Acetabulum; 15 — Pubic tubercle;
16 — Obturator foramen; 17 — Ramus