Message:   Pinbone Seperation

From: zappaz1     Sent: 07 Sep. 2000     Message 1 of 2

I ran across a photo that makes it easy to see the pinbones we have discussed before, and thought it might be of interest to those who are curious about what limits vaginal stretching distance. These bones we sit on are called the ischial tuberosities, or in more common language just "pinbones". Several have asked me what they have to do with vaginal stretching. Because these bones form the sides of the opening in the pelvis, the distance between them is the largest (side-to-side) distance the vagina can stretch open. During birth, the distance across the infants head can be this same size if the pelvis is not large, or the infant's head if quite large. In other words, this pinbone separation or distance is a limiting distance to vaginal stretching. How to measure this distance easily and the size variations of this distance, have been discussed before on Cindy and Joe. The picture shows two shiny areas of skin that represent the location of these bones just under the skin on each side of the anus. In this picture these bones appear to have a separation over five inches. The lady in the picture appears to stretch fairly easily and might be able to take something 5 inches across (the distance across a 3 liter pop bottle)

pinbones.jpg