- Best thought of as the Ischiococcygeus
- Origin: Tip of the Ischial Spine
- Insertion: Side of Coccyx and lowest piece of Sacrum
- Lies edge to edge with the lower border of Piriformis
- Overlapped anteriorly by Iliococcygeus
- Gluteal surface is fibrous tissue – is indeed the Sacrospinous Ligament
- Nerve supply:
- Branches of S3 and S4
