The Body as Nested Bags —
A Model for Thinking About Back Pain

I attended a two-day seminar on visceral manipulation run by a French osteopath — Paul Prevot — and came away with something I had not expected. Not a new technique, although the techniques were extraordinary. Something more fundamental: the realisation that everything I had studied separately in three years of undergraduate anatomy, physiology, and biochemistry was, in the hands of a skilled osteopath, the same subject.

The anatomy I learned at Glasgow — the serous membranes, the peritoneum, the pericardium, the nine abdominal cavities — had lived in my mind as structural knowledge. The physiology had lived separately. The biochemistry separately again. Paul Prevot spent two days demonstrating that these were never separate to begin with. That the physical position of an organ may affect how it works, and that how it works shows up in the biochemistry. That's the idea this post explores. It's a teaching model from manual therapy, and the rest of this page says where it is anatomy and where it is untested.

The Shopping Bags Within Shopping Bags

Your internal organs do not float freely inside an empty cavity. They are contained within a series of nested structural envelopes — serous membranes, fascial sheaths, and peritoneal folds — each with its own integrity, its own tension, its own relationship to the structures adjacent to it.

Think of it this way: your internal organs are the shopping. The peritoneal bags, fascial compartments, and serous membrane envelopes are the shopping bags containing them. And the suspensory ligaments — the coronary ligament of the liver, the broad ligament of the uterus, the mesenteric attachments of the intestines — are the handles by which those bags are suspended from their anchor points.

Those anchor points are your diaphragm and your abdominal wall.

This means that anything that changes the contents of a bag — enlargement, congestion, inflammation, displacement — changes the tension on the handles. Changes the tension on the handles and you change the load on the diaphragm. Change the load on the diaphragm and you change breathing. Change breathing and you change posture. Change posture and you change the load on the spine. That's the model: a chain in which back pain could start away from the back. Each link is plausible; the chain as a whole hasn't been tested.

The Liver — Reed Davis's Hoover Bag

Reed Davis — the founder of Functional Diagnostic Nutrition, under whom I trained — described liver congestion with one of the most useful clinical analogies I have encountered. The liver, he said, is like a hoover. It sucks up the dust and debris — the toxins, the metabolic waste, the hormones due for elimination — and processes them, making them safe for excretion. But as a hoover bag fills, it gets bigger. And when it gets too full, it starts to leak — dust back through the bag, polluting the inside of the machine, just as a congested liver recirculates toxins into the bloodstream it was supposed to be cleaning.

"Liver congestion" in this sense is a functional-medicine idea, not a medical diagnosis: a liver working hard, imagined as getting fuller. It's an analogy, not a measured state. Grade: mechanistic and untested. An enlarged liver is a real medical finding, but its common causes are fatty liver disease, alcohol, heart failure, infection and others. Those need a doctor to find, not a toxin explanation.

And here is where the anatomy Paul Prevot taught becomes directly relevant. Because a physically enlarged liver does not sit quietly in the right upper quadrant while the rest of the body gets on with things. It sits inside its bag. The bag has handles. The handles attach to the diaphragm and the abdominal wall. And a larger bag exerts more tension on its handles than a smaller one.

A note on liver blood tests. Raised ALT or AST has many causes: fatty liver disease, alcohol, medicines, viral hepatitis, muscle injury, coeliac disease, thyroid disease and more. A raised result needs your GP to work out the cause. It isn't something a fascia model explains or a manual technique treats. What the model adds is a question I ask alongside the medical work-up, not instead of it.

The Extracellular Matrix — The Environment the Cell Cannot Live Without

Named influence, not evidence. Alfred Pischinger was an Austrian histologist who spent his career studying what he called the ground regulation system — the extracellular matrix (ECM) that surrounds every cell in the body. His work was largely ignored by mainstream medicine for decades, partly because it was ahead of the available technology to investigate it and partly because it challenged the cell-centric model that had dominated biology since the nineteenth century.

The ECM is composed of collagen, elastin, proteoglycans, and glycoproteins embedded in a gel-like ground substance. It is continuous throughout the body — not a collection of separate local environments but a single interconnected medium that links every tissue and organ. In this sense the ECM is the biological equivalent of the fascial network: structurally continuous, functionally integrated, and capable of transmitting mechanical, chemical, and electrical signals across distances that direct cell-to-cell communication cannot bridge.

The functions of the ECM that Pischinger documented include:

• Providing the structural scaffolding for cells and organs
• Modulating cell-to-cell communication — including the biophoton emissions I wrote about in the previous post in this series
• Regulating the life cycle of cells — including programmed cell death
• Creating the balance between cell survival and cell death
• Modulating growth factor and cytokine function
• Maintaining the fluid balance and pressure gradients between tissue compartments

When the ECM is compromised — by chronic inflammation, by toxin load, by dehydration, by the mechanical stress of sustained postural compression — none of these functions occurs optimally. The cells within a compromised ECM are receiving degraded signals, eliminating waste into an already-loaded medium, and making growth and death decisions based on distorted environmental information.

In the model, the matrix is how a struggling organ could affect tissues elsewhere. Grade: mechanistic and untested. Pischinger's "ground regulation system" is a historical theory that hasn't been tested in clinical trials, and I've labelled it as an influence rather than evidence.

Thomas Myers and the Anatomy Trains

Named influence. Thomas Myers' Anatomy Trains framework — built on the fascia dissection work that followed from the tradition of Ida Rolf — provides the structural map for understanding how tension transmits through the body along predictable myofascial continuity lines.

The superficial back line runs continuously from the plantar fascia of the foot, up the calf, through the hamstrings, across the sacrotuberous ligament, up the erector spinae, over the cranium, and down to the supraorbital ridge above the eyes. Dissection studies support continuity along parts of these lines; how much force actually passes along them in a living person, and whether treating "the line" helps pain, is less clear. Grade: anatomy partly supported; clinical use untested.

The deep front line — Myers' most clinically important myofascial track — runs from the inner arch of the foot, up through the inner leg, through the psoas and iliacus, through the anterior spine, through the pericardium, and into the floor of the mouth and the cranial base. This is the line that connects the hip flexors to the diaphragm to the pericardium to the cervical spine in a single continuous fascial structure. In the model, this is the route by which an enlarged liver pulling on the diaphragm could load the psoas and the lower back. That's the hypothesis; it hasn't been tested.

"Fascia is more than packaging: it is continuous and under tension, and it can carry force from one region to another. How far that matters for pain is still being worked out."

The piezoelectric properties of collagen — its ability to generate electrical signals in response to mechanical deformation — add a further layer. Collagen is piezoelectric in the laboratory. Whether that signalling shapes cell behaviour in living tissue to a degree that matters clinically is unproven. The physical environment of the cell — which Pischinger said could not be separated from the cell itself — is electrically active. It is not passive scaffolding.

The Ileocaecal Valve — Where Biochemistry Meets Anatomy

The ileocaecal valve is the sphincter between the small and large intestine. Its job is directional: to allow the contents of the small intestine to pass into the colon, and to prevent the bacterial-rich contents of the colon from refluxing back into the small intestine. When this valve is dysfunctional — either failing to close adequately or stuck in a closed position — the downstream consequences are both structural and biochemical.

A valve that fails to close allows colonic bacteria and their metabolic byproducts to enter the small intestine and, through a permeable gut lining, into the portal circulation. The portal vein carries blood directly from the intestinal tract to the liver. Every toxin that crosses through a dysfunctional ileocaecal valve arrives at the liver first. The portal route from gut to liver is real anatomy. How much ileocaecal valve function contributes to liver load in people is not established. Grade: mechanistic.

Visceral manipulation practitioners work on the area of the valve by hand. I previously wrote that this "can restore normal valve tone". I haven't found a study that shows it, so I've removed the claim. Grade for manual treatment of the ileocaecal valve: none.

Visceroptosis — When the Bags Descend

Visceroptosis is the downward displacement of abdominal organs from their correct anatomical position. It was a common diagnosis a century ago and has largely fallen out of use. I don't know of good data on how common it is, or on whether it causes the symptoms sometimes attributed to it (lower abdominal distension, poor core function, pelvic floor weakness, altered bowel habit). Grade: mechanistic and untested.

The person with visceroptosis who presents to a personal trainer or physiotherapist for their poor core function is frequently prescribed abdominal exercises. In my coaching practice I prefer exercises that train the deep abdominal wall and breathing before repeated sit-ups or crunches. That's my practice, not a trial-tested rule.

Named influences. Paul Chek's inner unit / outer unit framework — itself building on the work of Professor Vladimir Janda on phasic and postural muscle patterns — distinguishes between the deep stabilising system (transversus abdominis, multifidus, pelvic floor, diaphragm working together as a pressure canister) and the superficial global system (the visible muscles that produce movement). In the model, a sagging abdominal wall and displaced organs would disrupt that canister from the inside. It's a useful way to think about core training. Grade: mechanistic and untested.

From First Principles to Clinical Application — Why the Journey Matters

I studied anatomy, physiology, and biochemistry as an undergraduate and spent the early years of my clinical career thinking about them in sequence: physical first, then physiological, then biochemical. The visceral manipulation seminar was the moment I understood that this sequence was an educational convenience, not a clinical reality. The body does not organise itself by academic department.

The model asks you to see an enlarged liver as a biochemical, physiological and structural event at once. As a way of asking questions, I find that useful. As an explanation of any one person's back pain, it is untested.

This is why understanding that travels from first principles — from anatomy and physiology and biochemistry at their foundations, through to their clinical integration — produces something qualitatively different from understanding that begins at the clinical application and works backwards. The practitioner who understands how the liver is suspended, why the diaphragm shares fascial continuity with the psoas, and how the gut connects to the liver through the portal circulation asks different questions. Whether a client's back pain, constipation and liver enzymes are one problem or three is something to find out, not assume.

The body you are living in is one connected structure. The most useful thing any practitioner can do is learn to see it that way.