The internal pelvic examination is performed with the patient in the supine position, the vulva is sterilized, the examiner wears gloves and applies lubricant and moves gently to measure the diagonal diameter, the interosseous diameter and the width of the sciatic notch. The finger enters the vagina and measures the midpoint of the superior sacral capsule and the inferior border of the pubic symphysis to determine the length of the diagonal diameter, with a normal range of 12.5-13 cm, followed by the bilateral sciatic interspinous diameter, with a normal range of about 10 cm. Then after that is the measurement of the width of the sacrospinous ligament by placing the intravaginal index finger on the ligament and moving it, usually 5.5-6cm is normal.