Coccygeus Muscle

Description

Arising from the ischial spine on the lateral pelvic wall, the coccygeus muscle (ischiococcygeus) courses medially and posteriorly in a triangular sheet toward the inferior sacrum and coccyx. Its superior surface faces the pelvic cavity, lying posterior to the levator ani and forming part of the pelvic diaphragm’s posterolateral margin. Along its posterior border, the coccygeus blends with the sacrospinous ligament, creating a fibromuscular plane between the ischioanal region inferiorly and the presacral fascia posteriorly. Orientation is clear. You can follow the muscle from its lateral bony origin to its medial insertion. This internal pelvic view matters because coccygeus and levator ani define the route of several key neurovascular structures at the ischial spine, including the pudendal nerve and internal pudendal vessels as they turn around the sacrospinous ligament to enter the perineum. That relationship becomes concrete during pudendal nerve blocks and in posterior pelvic floor repairs, where needle placement and dissection near the ischial spine can injure the nerve or adjacent vessels. Pain syndromes also live here, coccygodynia and pelvic floor myalgia may involve hypertonicity or tenderness at the coccygeus insertion on the coccyx. Use this illustration in pelvic anatomy and pelvic floor modules for medical and PA curricula, and as a figure in colorectal, urology, or gynecology texts that address the pelvic diaphragm and ischial spine landmarks from an intrapelvic perspective. It also supports operative teaching for transvaginal sacrospinous fixation and for anesthesia references covering pudendal nerve block anatomy in male patients. Anatomical accuracy verified by SciePro's Medical Advisory Board.