The sacrococcygeal membrane is a tough fibrous
membrane
A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. ...
about 10mm long which extends from the inferior tip of the
sacrum to the body of the
coccyx
The coccyx ( : coccyges or coccyxes), commonly referred to as the tailbone, is the final segment of the vertebral column in all apes, and analogous structures in certain other mammals such as horses. In tailless primates (e.g. humans and othe ...
in humans. It covers the inferior limit of the
epidural space
In anatomy, the epidural space is the potential space between the dura mater and vertebrae (spine).
The anatomy term "epidural space" has its origin in the Ancient Greek language; , "on, upon" + dura mater also known as "epidural cavity", "e ...
and is analogous to the
ligamentum flavum found at other levels in the
spine.
It can be found at the apex of an
equilateral triangle
In geometry, an equilateral triangle is a triangle in which all three sides have the same length. In the familiar Euclidean geometry, an equilateral triangle is also equiangular; that is, all three internal angles are also congruent to each oth ...
whose base is formed by the dimples overlying the
sacro-iliac joints. The ''cornua'' of the sacrum may be palpated with a finger; the sacrococcygeal membrane lies between and inferior to these.
References
Thorax (human anatomy)
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