Muscle
Coccygeus (ischiococcygeus)
The small muscular component behind levator ani
High-yield
Find coccygeus on the pelvic side of the sacrospinous ligament. Its attachment runs from the ischial spine to the lower sacrum and coccyx.
Overview
Coccygeus spans the region between the ischial spine and lower sacrococcygeal skeleton. It lies against the pelvic surface of the sacrospinous ligament and may contain substantial fibrous tissue. Together with levator ani it completes the pelvic diaphragm, while remaining a distinct muscle.
Reference facts
- Origin
- From the ischial spine and adjoining sacrospinous ligament.
- Insertion
- To the lateral coccyx and inferior sacrum.
- Innervation
- Direct lower sacral nerve branches, commonly described as S4–S5; segmental descriptions vary among sources.
- Action
- Supports the posterior pelvic floor and assists control of coccygeal position.
- Blood supply
- Small branches from the internal iliac arterial network, including inferior gluteal and internal pudendal contributions.
Clinical correlation
The coccygeal plexus lies within or closely associated with this muscle. The nearby pudendal neurovascular bundle and sacral nerves make this a clinically important region in pelvic support surgery and assessment of coccygeal pain.
Frequently asked questions
What does the coccygeus (ischiococcygeus) do?
The coccygeus (ischiococcygeus) supports the posterior pelvic floor and assists control of coccygeal position.
What nerve innervates the coccygeus (ischiococcygeus)?
Direct lower sacral nerve branches, commonly described as S4–S5; segmental descriptions vary among sources.
Where does the coccygeus (ischiococcygeus) attach?
Origin: From the ischial spine and adjoining sacrospinous ligament. Insertion: To the lateral coccyx and inferior sacrum.
What is the blood supply of the coccygeus (ischiococcygeus)?
The coccygeus (ischiococcygeus) is supplied by the small branches from the internal iliac arterial network, including inferior gluteal and internal pudendal contributions.