Correct Anatomical Position of the pelvis

Hi Liminalpool,

(edited 2/13/19)

Standing and supine x-rays of the hip do not show the pelvis in its correct “ring-on-edge” position. This is because the pelvis (ilia) covers the hip joints when looking straight on from front to back. Therefore, an “AP” radiograph must position the patient in such a way (hips internally rotated, sometimes a bolster placed under the knees so lumbar spine is flattened) so the hips are more visible. The resulting distortion appears as if there is a short wall of pubic bone at the front of the body. When in fact, the x-ray beam is actually focused as if looking up at the pubic bones from below.

When lying on your back, if you were able to see into your pelvic cavity, as is often portrayed in surgical photos or illustrations, you would see your pubic bones running from front to back. When you stand up, your lumbar spine rotates the pubic bones well underneath you. This is why when you feel your pubic bones vaginally, they are positioned at the back of the body, which is a surprise because all medical illustrations misrepresent them as a short wall of bone in front.

In any event, the x-ray beam is directed too low to capture the correct position of the standing pelvis. I know this is difficult to understand, and I struggled with it for many years. It gets even more convoluted and disorienting when you look into how "3D" CT scans of the pelvis are digitally constructed to portray the pelvis in a supposedly standing orientation. This is why I teach women to self-verify how their pelvis is really positioned, and why it matters.

This subject is very worthy of a blog post, which I will try to do in the not-too-distant future.

Christine

Hi Liminalpool,

Gynecologic MRIs are equally faulty in terms of misrepresenting normal standing anatomy of the female pelvis and pelvic organs. Software is used to rotate these images into the “anterior pelvic plane” in order to standardized the view. It is no surprise that this view reinforces the AP radiograph view.

The medical system has chosen to reinforce this view - the anatomical framework upon which all “pelvic floor” surgeries are based, rather than correct it and adopt a holistic understanding of pelvic organ support.

With the view of a hole in a “pelvic floor” at the bottom of the torso, it is easily argued that the vagina must be made smaller, tighter, stronger to keep the organs from falling out. All vaginal surgeries for prolapse are based on this erroneous concept. The organs are supported by the lower abdominal wall and away from the outlet at the back. The pelvic wall’s primary purpose is to rebound intraabdominal pressure, which it does by being broad like a trampoline when the tailbone is lifted and the sit bones wide.

As far as the “dome shaped” pelvic floor discovery with pelvic contraction in the supine position goes, in reality the pelvic wall at the back of the body is crunching slightly forward as the vaginal sphincter tightens like a draw-string purse. As it does so, the back of the bladder is being pulled toward the front vaginal wall and the lower rectum is pulled toward the back vaginal wall - in other words, in the direction of prolapse. You might find this blog post useful, although here I am talking about transabdominal ultrasound:

https://wholewoman.com/blog/?p=1750

I feel the back of my horizontal pubic bones underneath me at the back of my body, as do all women to whom I point this out. The muscle wall is connected from the back of the pubic bones to coccyx, all clearly at the back of the body.

If nature made the pubic bones slope downward from front to back, and the soft muscle wall slope upward from pubic bones to coccyx (which of course it does), what would happen at the point where they both meet at the back of the pubic bones? It would become very susceptible to the bladder being forced into that V-shape space, which is actually what happens when the pelvis is habitually tucked under. Thus the enormous rates of cystocele.

Humans have a choice of holding their body in such a way that the pubic bones are horizontal, or even angled slightly up toward the coccyx from front to back. Or, they can angle ever so slightly down, which creates a gravity-dependent spot that pulls the pelvic organs into it.

In no way can anyone - even the most nimble contortionist - stand with her pubic bones in the bowl position. Standing with the pelvis in the “anterior pelvic plane” of standard imaging views would require the most severe slouch you could possibly muster.

Hope this helps.

Christine

You are welcome, Liminalpool. It makes a huge difference whether women believe their vagina is like a tree trunk that must be made stronger, tighter, smaller, or understand the reality that the pelvic organs are supported by the lower abdominal wall and not an imaginary "pelvic floor".