The coccygeus is the most posterior component of the pelvic diaphragm, overlying the sacrospinous ligament from the ischial spine to the coccyx and lower sacrum. It completes the posterior pelvic floor alongside the iliococcygeus. Its overlap with the sacrospinous ligament makes the two structures inseparable surgically, and sacrospinous fixation for vault prolapse is performed through the coccygeus-sacrospinous complex. Coccygeus spasm contributes to levator ani syndrome and coccydynia.
| Origin | Ischial spine and sacrospinous ligament |
|---|---|
| Insertion | Lateral border of the coccyx and the adjacent sacrum |
| Nerve Supply | Branches from S4 and S5 |
| Blood Supply | Internal pudendal artery |
| Actions | Supports the pelvic floor posteriorly; Flexes the coccyx after defaecation; Assists in closing the pelvic outlet |
|---|
By flexing the coccyx back to its neutral position after it is deflected during defaecation and parturition, the coccygeus restores the structural integrity of the posterior pelvic outlet.
Coccygeus tenderness on rectal examination is a consistent finding in levator ani syndrome and is more specifically assessed by pressing on the muscle belly between the ischial spine and coccyx. Transvaginal or transrectal trigger point injection and physiotherapy to the coccygeus provide relief in refractory pelvic floor pain syndromes. Sacrospinous ligament fixation for apical vaginal prolapse requires transecting the coccygeus to reach the ligament.
Assessed by rectal or vaginal examination between the ischial spine and coccyx, identifying tenderness and spasm that reproduces pelvic floor pain.
Pelvic floor muscle spasm producing coccydynia and levator ani syndrome managed with physiotherapy, trigger point injection, and TENS therapy.
