The ischiocavernosus muscle (erectores penis or erector clitoridis in older texts) is a muscle just below the surface of the perineum, present in both men and women.

[1] It arises by tendinous and fleshy fibers from the inner surface of the tuberosity of the ischium, behind the crus penis; and from the inferior pubic rami and ischium on either side of the crus.

From these points fleshy fibers succeed, and end in an aponeurosis which is inserted into the sides and under surface of the crus penis.

In females, the ischiocavernosus muscle assists with clitoral erection.

This article incorporates text in the public domain from page 428 of the 20th edition of Gray's Anatomy (1918)