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The End of the “Neutral Pelvis” – Part 1

“There is an ecology of bad ideas, just as there is an ecology of weeds, and it is characteristic of the system that basic error propagates itself. It branches out like a rooted parasite through the tissues of life, and everything gets into a rather peculiar mess.”

Gregory Bateson
Steps Toward an Ecology of Mind


Chronically pulling in the abdominal wall in the name of health, strength or aesthetics is the most deeply held tenet of Western physical culture. It was likely first displayed by the men who introduced yoga into modern society with postures that pulled navel to spine. Yoga attempted further control of intraabdominal pressure with exercises like mula banda, which contracts the pelvic diaphragm.

In the early part of the 20th century, Joseph Pilates greatly expanded the idea of focused abdominal exercise toward a goal of establishing “core strength”. Photographs of Pilates reveal a forced physical condition where a perpetually contracted abdominal wall rotated his arms forward and his legs outward. Despite such a departure from natural physiology, a contracted and rippled abdomen became the central feature of ideal male form.

Henry and Florence Kendall were a husband and wife team of physical therapists who practiced in the 1940s and 1950s. They developed the concept of “neutral pelvis” where a line drawn between the anterior superior iliac spine (ASIS) and posterior superior iliac spine (PSIS) is parallel to the horizontal plane in standing posture. The Kendalls described “pelvic tilt” as the degree to which the position of the pelvis deviates from “neutral”. They proposed that four muscle groups are responsible for supporting the pelvis in its proper alignment: the erector spinae, the hamstrings, the abdominals and the hip flexors. When these muscles are in “balance”, the pelvis was thought to be maintained in neutral alignment. Science has never been able to prove this theory.

Ida Rolf, creator of a myofascial release system called Structural Integration, asserted that the pelvis is “horizontal” when the bottom of the tailbone is level with the “top” of the pubic symphysis. Rolf’s views were based upon widespread misunderstanding of human pelvic position.

The neutral pelvis was brought further under scientific scruitiny during the 1990s when physical therapists Paul Hodges and Carolyn Richardson attempted to prove that certain muscles, particularly the transversus abdominis, provide core stability to the torso, thereby reducing back pain. Within a decade “core stability” was the mantra being repeated worldwide by exercise physiologists, yoga instructors, physical therapists, and others.

There is no such thing as the Kendall’s neutral pelvis because in standing with the lumbar curve in place the ASIS are rotated all the way forward, with the pubic bones positioned between the legs in a front-to-back direction. To stand with what is described as a neutral pelvis one must maximally tuck the tailbone under. Many Western scientific and medical disciplines, from anthropology to orthopedics, perpetuated the myth of the neutral pelvis by proclaiming that a 90 degree posterior rotation occurred when human beings became bipedal. In the conventional “bowl” orientation of the pelvis, a strong abdominal wall and fortified pelvic “floor” are the only defense against the weight of internal organs plunging down from above.

While physical therapists continue to debate which musculoskeletal alignments result in the most neutral pelvis, what about the position of the organs? For almost a century optimum posture has been described in terms of length and strength of muscles, when in fact anatomic placement of organs is primary in the analysis of human posture. The dynamics of breathing under the forces of gravity position the abdominal and pelvic organs in a specific way, which in turn defines natural human posture.

In a newborn baby girl, the urethra/bladder, vagina/uterus, and rectum/sigmoid colon form long, straight axes through her pelvis. When she begins to stand, walk and run under the forces of gravity, the movement of her respiratory diaphragm pushes her pelvic organs down and forward. By late puberty her organs have bent ninety degrees to rest atop her pubic bones and against her lower abdominal wall. The paired round ligaments of the uterus, which travel down either side of her lower abdominal wall and embed in the labia surrounding her vagina, assist this forward movement.

The bladder is tethered to the anterior abdominal wall by the median umbilical ligament, which extends from the top of the bladder to the umbilicus. Continuous with the umbilicus is a fibrous cord called the round ligament of the liver. What was once the fetal umbilical vein, the round ligament extends from the umbilicus to the inferior surface of the liver. The liver is the largest organ in the body, weighing in at 1200-1600 grams. The large falciform ligament separates right and left lobes and attaches the liver to the anterior abdominal wall.

The coronary ligament branches from the falciform ligament, extending over the superior surfaces of the right and left lobes, adhering the liver to the inferior surface of the diaphragm. The small intestine is also connected to the diaphragm by way of the Treitz ligament. The ascending colon and descending colon are fused to the posterior abdominal wall.

Anatomic motion of the respiratory diaphragm moves the liver, stomach, pancreas, spleen, intestines, bladder and uterus down and forward with every inspiration. Diaphragmatic breathing is not only “natural” and “correct”, it is the way the body is designed, or has evolved, to function.

Natural human anatomy is self-evident. All young children develop the same puffed out abdominal wall, which elongates as the child grows. By adulthood diaphragmatic-liver-abdominal wall support to the chest and shoulder girdle is evidenced by a “proud holding” of the upper abdominal wall.

The curvilinear abdominal wall provides direct support to the liver and bladder by way of central ligamentous attachments. Chronically pulling in the wall collapses fascial support and shifts intraabdominal pressure toward the pelvic outlet.

The concept of the neutral pelvis is based upon deep and age-old anatomical misunderstanding. Habitually pulling in the belly is foreign to natural sensibilities and has the potential of causing serious disorders, from hiatal hernia and gastritis to incontinence and prolapse.

Join us next month for The End of the “Neutral Pelvis” – Part 2 where we will discuss the thoracic cavity and the inherent danger of a postural model based in mechanical, reductionistic science.

{ 11 comments… add one }
  • Matt Whitehead January 10, 2014, 4:30 pm

    Hi Christine, I just happened upon this article and your site. It’s good to see someone explaining to women (and men) that a so-called “neutral” pelvis is usually a posteriorly tilted pelvis and not normal or functional. I am amazed how many clients come in with chronic hip and lower back pain and are working on pulling their stomach in more because they were told they are too anterior in their pelvis by a PT or pilates instructor and when I take photos of their posture they are actually posterior and need more anterior tilt of their pelvis. Keep up the good work. – Matt

  • Petr May 29, 2013, 2:03 am

    I am really sorry, but author of this article did not understand the term “Neutral pelvis”. It needs holistic approach. All joints can be in neutral position. If you speak about neutral pelvis, you must also put it together with neutral chest position. Otherwise, it does not make a sense to assess the neutral pelvis position. Our body is one unit.

  • Curious April 17, 2013, 12:29 pm

    Does this apply to males also? or only females?

  • admin August 20, 2012, 12:05 pm

    Hi Susan,

    The human pelvis is rotated all the way forward when a healthy lumbar lordosis is in place – into the quadrupedal position with the ASIS low in the groin, the PSIS at the top of the posterior aspect of the ilia and the pubic bones underneath and in between the legs, like straps of a saddle. The ASIS are at the bottom, anterior aspect of the ilia and the PSIS are at the top, posterior aspect. They are diagonal to one another. This is all self-evident, although the PSIS are difficult to palpate. Sit down with full lumbar curvature to best feel your ASIS – it will be resting on your thigh. Place a hand on your tailbone and stand up. Witness that the pelvis does not rotate, but stays exactly in this horizontal, quadrupedal position. The pelvic organs rest against the lower belly and not on top of a muscular pelvic “floor”. The pubic bones are the true bony pelvic floor and the outlet is at the back, away from the organs at the front. All modern exercise and therapeutics are geared toward a non-existent, 45-degree posterior rotation of the pelvis into a “bowl”. The only time the pelvis becomes anything near a bowl is when the spine is in total flexion with the tailbone flexed as far under as possible, which is the position of instability for both spine and pelvic organs. Amazing, but true.

    Christine

  • Susan August 20, 2012, 10:06 am

    Hi Christine,
    Interesting. I’m curious now as to how you might best describe a neutral pelvis. Are the ASIS slightly anterior to the PSIS when standing in neutral according to what you are saying? That is how I see it to be but not sure how you would say it. I see what you are saying about the Kendall theory but as a Pilates instructor, how might I understand neutral from your point of view.

  • Dianne April 12, 2012, 4:07 pm

    Brilliant.

  • Ruth April 8, 2012, 5:44 pm

    Christine,

    Excellent!!!! I am looking forward to reading part 2.
    Thank you for the time and energy you put into this necessary education.

  • Louise March 18, 2012, 11:19 pm

    Hmmm, I have never before considered what is happening on the other side of the proverbial six pack, viewed from the inside of the body. It now looks to me like a floppy hang glider wing, or surf kite that has lost its wind, and so has lost its ability to perform its function, and support anything (or anyone) on the concave side. All that spare soft tissue flopping around inside the abdomen is not going to support anything, just like floppy parachute strings, which only keep the parachute open when they are stretched tight!

    Say your prayers, six packers!

  • Carol Bilek March 7, 2012, 4:27 pm

    Thank you,Christine. This is a wonderful, organized and very informative article. It makes a lot of sense!
    Carol

  • Lindy Roy March 3, 2012, 5:02 am

    Hi Christine,
    Thank you for this very thorough analysis of the female pelvic structure, pelvic organ support and natural female posture. It is also a fascinating example of how sometimes mistaken theories can become accepted as facts and then these facts can develop into a large body of material. Thank you Christine for explaining the reality of how women’s bodies are actually structured and supported. I am looking forward to further health care systems developing which suit this revised understanding.
    Best wishes, Lindy Roy

  • Betsy March 2, 2012, 9:32 am

    Christine, this is a terrific article, and the pictures add so much. That cute little babe in the perfect WW posture is an image that’s burned into my brain now! Looking forward to part 2.

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