Similar to a tinel sign digital palpitation of the ischial spine may produce pain.

The ischial spine, an easily identifiable structure on CT, is used as the level of injection.

Station refers to the relationship of the fetal presenting part to the level of the ischial spines.

This is the relationship between the presenting part, whether that is the head, shoulder, buttocks or feet, and the ischial spines.

When the presenting part is at the ischial spines the station is 0 (synonymous with engagement).

If the presenting part is below the ischial spines, the distance is stated as plus stations (+1cm to +4cm).

A further examination found the cervix still at 8cms dilatation and the head at the ischial spines.

The anesthesia is produced by blocking the pudendal nerves near the ischial spine of the pelvis.

It lies between the posterior inferior iliac spine (above), and the ischial spine (below).

Android: triangular inlet, and prominent ischial spines, more angulated pubic arch.

The ischial spine separates the greater and lesser sciatic foramina at the exit of the bony pelvis.

Midpelvis: The line between the narrowest bone points connects the ischial spines; it typically exceeds 12 cm.

The ischial spines and tuberosities are heavier and project farther into the pelvic cavity in males.

A spinal needle is advanced via the gluteal muscles and advanced within several millimeters of the ischial spine.

No head should be palpable abdominally and the vertex should have reached the level of the ischial spines on vaginal examination.

In contrast, patients may report temporary relief with a diagnostic pudendal nerve block (see Injections), typically infiltrated near the ischial spine.

From its posterior border there extends backward a thin and pointed triangular eminence, the ischial spine, more or less elongated in different subjects.

If the presenting part lies above the ischial spines, the station is reported as a negative number from 0 to -5, where each number represents a centimetre.

The pudendal vessels and nerve pass behind the sacrospinous ligament directly medially and inferiorly to the ischial spine.

Separate centers are frequently found for the pubic tubercle and the ischial spine, and for the crest and angle of the pubis.

It then crosses the ischial spine, reenters the pelvis through the lesser sciatic foramen, and pierces the pelvic surface of the obturator internus.

The coccygeus, situated behind the levator ani and frequently tendinous as much as muscular, extends from the ischial spine to the lateral margin of the sacrum and coccyx.

Vaginal examination confirms a cephalic presentation, the cervix is anterior, thin, partially effaced, 3cm dilated and poorly applied to the fetal head which is at a station 2cm above the ischial spines.

These arise between the symphysis and the ischial spine and converge on the coccyx and the anococcygeal ligament which spans between the tip of the coccyx and the anal hiatus.

Ms F assessed Mrs B on admission and found her cervix to be 8-9cms dilated and the baby's head to be 1cm above the ischial spines (bony outcrops in the maternal pelvis).