How The CORE Really Works

The Effects of Buoyancy on Posture, Structure and the CORE via Internal Water (Hydrostatic) Pressure:

When we describe proper posture and structure and how the CORE works, and how to improve your posture, we’ll be emphasizing a process for maintaining length through the whole torso, especially in the abdominal and lumbar region.

Relaxed & Lengthened Muscles
& Water Pressure More
Important Than “Strength”
for Good Posture

A Primary Key is to discover how to improve your posture is that movement of your upper torso (rib cage, chest & spine) upward away from your pelvis is not so much from your muscles (such as the back muscles) pulling or lifting you upward, but more from the relaxation & lengthening of your muscles on front, sides and back of your abdomen and lumbar spine, allowing water pressure within your belly to buoy you upward into better posture and a more upright structure.

Contrast between Over-Shortened muscles of The CORE here, versus Relaxed & Lengthened Abdominal Wall Muscles (refer back to the illustration above):

In the illustration above, the person has over-contracted and therefore over-shortened abdominal muscles (see illustration of those muscles below). The abdominal cavity contains a large percentage of water. Think of your belly as a large water balloon reacting directly to whichever direction your muscles are pulling, squeezing and therefore directing the water pressure.

In the above illustration, the abdominal muscles of The CORE pull down on the ribcage, producing slumped forward posture, and compressing the overall structure.

It’s important to remember that water is NOT compressible. You cannot “squeeze” water into a smaller space. Whatever volume of water you have in an area is preserved, unless the amount or quantity of water is reduced. Otherwise, water can be redirected, but not compressed.

However, if there is enough pressure on the water within various compartments of the body, the body will, via the process of osmosis, move the water out of the area.

Osmosis moves fluids from areas of higher pressure to areas of lower pressure.

Muscles of The CORE Structure

The most well known abdominal wall muscles of The CORE are the Rectus Abdominus — AKA lumbar flexors — and Internal & External Obliques — AKA lumbar flexors & rotators — running more-or- less vertically, as in the illustration below:

These are most of the muscles most directly exercised and chronically shortened in most so-called “AB strengthening” exercises — unless they are using sufficient TSRS (Tension & Stress Reduction Strategies).

This shortening of the abdominal wall is accomplished by exercises such as sit ups, crunches, pelvic tucks and the like (see next illustration, below). These muscles are pulling down on his ribcage and chest, compressing the contents of his abdomen, which contains a high percentage volume of water.

Once Again:

The downward pressure squeezes the belly and the internal water pressure moves out of the way, downward and outward, causing the belly to pouf outward, as in love handles & pot belly. That’s one reason why some people with no fat on them, even though doing endless sit ups and crunches, still get love- handles & pot-belly.

This downward pulling action of the abdominals also causes forward neck & head posture, visible in the person illustrated above. Notice also the loss of lumbar curve (flattening of the lumbar spine), which also contributes to forward neck & head, and puts excess pressure on the lumbar spinal discs.*

* This action — flattening of the lumbar spine, or loss of the natural spinal curve — produces the majority of forward neck & head posture we often hear and read about. Many therapists, therapy trainings and books teach the exact opposite of that statement, saying that too much forward lumbar curve and a forward (anterior) tilted pelvis creates forward neck & head posture.

Transversus Abdominus Muscle of The CORE Buoys Ribcage UP-ward

The opposite is to discover how the ribcage is buoyed UP. The primary muscle for that, and less well known muscle of The CORE, is the Transversus Abdominus (TA):

The Transversus Abdominus (TA) muscle fibers run horizontally, around the belly area. The TA squeezes inward on the abdominal cavity, compressing the contents, which includes a high volume of water. This increases the internal, hydrostatic (water) pressure within the abdominal cavity, which then pushes the ribcage upward:

This is the primary musculoskeletal relationship controlling overall posture and structure of the torso, spine, neck & head.

THE TRICK then is to keep the rectus abdominus and oblique muscles (and the latissimus dorsi which I’ve not mentioned here) relaxed & lengthened so they do not interfere with the upward action of the transversus abdominus.

The best exercises to improve posture then are those that STRETCH the senior muscle of the abdominal region.

Therefore, when it comes to basic stand-in or sitting posture, poor posture is NOT the result of “weak back muscles.” It’s the result of over-shortened abdominal muscles. Keeping the abdominal muscles relaxed & lengthened allows the internal water pressure within the abdominal cavity to keep the ribcage buoyed up with minimal muscular effort.

I hope this has helped you better understand the elements of improving your posture, structure and The CORE.

Thanks for Reading,
David Scott Lynn (DSL*)
* DSL: Your Hi-Touch Up-Link to the Inner-Net
Inner-Net: Your Psycho-Neuro-Musculo-Fascial System