The ischiocavernosus muscle covers the crus of the erectile tissue and compresses it during erection, preventing venous outflow from the corpus cavernosum and maintaining penile or clitoral rigidity. It is the muscle responsible for the rigid phase of erection, and its failure allows venous escape and erection loss. The ischiocavernosus is tested clinically as part of the bulbocavernosus reflex assessment.
| Origin | Inner surface of the ischial tuberosity and ischial ramus |
|---|---|
| Insertion | Crus of the penis or clitoris |
| Nerve Supply | Perineal branch of the pudendal nerve (S2, S3, S4) |
| Blood Supply | Perineal artery |
| Actions | Compresses the crus of the penis or clitoris to maintain erection; Assists in ejaculation in males |
|---|
By compressing the crus against the ischiopubic ramus it raises intracavernous pressure above systolic blood pressure, producing the fully rigid phase of erection that cannot be achieved by vascular filling alone.
Perineal nerve injury from prolonged bicycle saddle pressure can produce ischiocavernosus and bulbospongiosus weakness contributing to erectile dysfunction and perineal numbness — cyclists' syndrome. Strengthening pelvic floor muscles including the ischiocavernosus through pelvic floor physiotherapy improves erectile function in men with mild to moderate erectile dysfunction from venous leak.
Not accessible to external palpation due to perineal position.
Perineal nerve and ischiocavernosus compression from bicycle saddle producing erectile dysfunction and perineal numbness, managed with perineal pad modification and nerve recovery time.
