Integrating Japanese Eastern medicine with Western medicine.

Core Stability = Diaphragmatic Breathing

For many people, chronic back pain, neck pain, headache, and a host of other ailments can be linked back to a common cause: losing the habit of diaphragmatic breathing.

Diaphragmatic breathing is an even expansion of the ribcage, produced by the diaphragm muscle in coordination with a group of muscles commonly associated with our “core”.

Many of us breathe primarily by using our neck and chest muscles to lift our ribs and collar bones up in the front – toward the front of our necks – and also with our back muscles – to pull our ribcage down in back. But overuse of these muscles not only produces shallow and ineffective breathing, it also creates postural distortions  – such as forward head posture and lumbar hyper-lordosis – that can cause or perpetuate chronic pain, physical impairment and disability.

If we overuse the muscles of our necks and backs with every breath we take – and we breathe more than 20,000 times each day – there is little hope that these muscles will be able to relax. Eliminating these muscle tensions permanently requires re-learning diaphragmatic breathing.

When the diaphragm fills our lungs with air as it’s meant to, we relax in body and mind. Diaphragmatic breathing activates the parasympathetic (rest and relaxation) part of our nervous system. And when the neck, chest and back muscles are freed from overworking with each breath, they return to normal resting tone, ready to move our bodies, the job they are really meant for.

Diaphragmatic breathing = core stability. Core stability = diaphragmatic breathing.

For the diaphragm to fill our lungs the way nature intended, the way it did when we were children, we need our abdominal muscles to play a larger role. Specifically, our outer abdominal muscles, the obliques, as well as the deepest layer of the abs, the transverse abdominis, need to work together to keep our ribcage from rising up in the front. When the ribs above and to the sides of our bellies are held down by our abs, the diaphragm regains the shape and leverage required to expand the chest and lungs in all directions, thereby relieving the back, chest and neck muscles of their burden of overwork.

But the “core” is really more than the abs. Little known muscles on the side and back of the ribcage – known as the serratus anterior and trapezius muscles – coordinate with the abdominal muscles to support and enable healthy posture and diaphragmatic function.

When this happens, the diaphragm assumes a special dual role: it pulls air into our lungs and also provides stability to our posture and our spine through harmonious cooperation with all the muscles of our core. To breathe diaphragmatically is to engage the core muscles, not only in the abdomen, but throughout our thorax as well. This wholistic muscle engagement produces intra-abdominal pressure, or pressure within our abdomens.

Above the abdomen, the diaphragm, now positioned correctly by the muscles of the core, presses down on our abdominal contents; below, the muscles of the pelvic floor resist by increasing tone and lifting slightly up. And all around, the abdominal and back muscles work together to create a cylinder that contains and regulates intra-abdominal pressure.

Intra-abdominal pressure is a key to spinal stability. It’s like having a ball inside our belly that presses backward against the spine, supporting it. This relieves the back muscles of working too hard, which further improves the balance of muscular activity through our core. The abdominal muscles work harder, and the overworked back muscles, which had been pulling us into hyper-lordosis, can relax and stretch out.

With breathing now performed by the diaphragm and the concerted action of our core, the muscles of our neck and chest, known also as “accessory breathing muscles,” can stop working so hard, and get back to their real jobs – to move our head, neck and arms.

Diaphragmatic Breathing requires that our core muscles are active and engaged. Active and engaged core muscles, in concert with the diaphragm, produce intra-abdominal pressure that stabilizes our spine and integrates our posture. Breathing diaphragmatically requires, and produces, core stability. If we breathe diaphragmatically, we have core stability. If we have core stability, we can breathe diaphragmatically. Diaphragmatic Breathing = Core Stability.

To regain the ability to breathe diaphragmatically, most people need to re-learn how to fully exhale. If we are breathing with our neck and chest muscles, those muscles invariably pull our heads forward, out in front of our bodies, and our chests up, towards our necks. This lifts up the front of our ribcage, expanding it, and increases the diameter of the bottom of the ribcage. In turn, this posture stretches out the abdominal muscles, effectively turning them off. The diaphragm flattens and loses its ability to pump air and to produce spine-stabilizing intra-abdominal pressure. The back muscles tighten to protect the unstable spine and help us breathe, pulling our lumber spines into tight arches of hyper-lordosis. In this posture, our lungs are over-filled with air, or hyper-inflated. We are stuck in an exaggerated posture of inhalation:

Suboptimal AIC

Notice in the image above how the head is jutting forward, the chest is lifted and expanded, and the diaphragm (represented by the curved top portion of the red line) is flattened. This is a postural pattern dominated by hyper-inflation, and reflects an inability to breathe diaphragmatically. 


Many of us haven’t exhaled fully in years, and so remain stuck in the posture above. For more on the importance of a full exhalation, and on breathing in general, see here. 

Once we’ve learned again to exhale fully, which involves dropping and shrinking the ribcage through activation of the core muscles while relaxing the neck, chest and back muscles, we can remember how to inhale without lifting up the chest. At the end of a full exhale, the abdominal muscles contract to help squeeze air out of the lungs. If we keep those muscles active as we start to inhale, they will anchor the bottom of the ribcage, restoring the curved shape of the diaphragm, which can then pump air into our chests without the help of the neck, chest and back muscles. Breathing diaphragmatically restores muscle balance throughout the trunk, but it also restores posture:

Optimal AIC

The image above shows the posture of a diaphragmatic breather. Note that the head is balanced atop the spine, rather than jutting forward; the chest is dropped and relatively compressed, especially at the bottom of the ribcage, where the diaphragm is. This restores the abdominal muscles to proper length, and they can resume their powerful and necessary activity. The arched top of the red line – representing the diaphragm – is now in a tight curve. That curved shape restores the proper relationship between the diaphragm and the interior of the ribcage. That close relationship is known as a zone of apposition, because the diaphragm is now apposed to the chest wall, rather than being flattened out and pulled away from it, as in the first image, above.

Some people have hyper-inflated chests and inactive core muscles on both sides of their body, others only on one side. Restoring zones of apposition, and thus diaphragmatic breathing, is the speciality of the Postural Restoration method of physical therapy.

Those of us who are hyper-inflated on both sides of our bodies are referred to as having hypertonic, or tight, muscles of the Posterior Exterior Chain (PEC). This chain of muscles includes the low back muscles mentioned previously, as well as the powerful latissimus dorsi muscles (“lats”). Learning to relax these muscles by exhaling fully in various special positions is the crucial first step for people with this postural pattern. For more on the PEC pattern, and the physical problems associated with it, see this page. 

Other people are hyper-inflated on only one side of their bodies, nearly always the left side, and their postural pattern is dominated by hypertonic muscles of the (Left) Anterior Interior Chain (L AIC) of the leg, hip and lower back, as well as the Brachial Chain (BC) of the chest, neck and arm. The Left AIC and Right BC patterns can sometimes exist independently of each other, but usually co-exist and perpetuate each other. For more information on the L AIC pattern, see here, and on the R BC pattern, here

Postural Restoration, as taught by the Postural Restoration Institute (PRI), and practiced at FuncPhysio, is unique in the world of physical therapy, in that breathing is central to everything a patient is taught to do. Sophisticated and ingenious exercises and activities are tailored to each individual patient, each designed to teach them to facilitate muscles that need to be more active (e.g. the abdominal obliques) while simultaneously inhibiting (relaxing) the muscles of the PEC, L AIC or R BC that are stuck in chronic overwork..

In each therapeutic activity prescribed by your therapist, complete exhalation and deep inhalation is practiced to restore diaphragmatic breathing. For just as dysfunctional posture is perpetuated by dysfunctional breathing, good posture, core stability and ease and efficiency of movement is restored and continually renewed by diaphragmatic breathing. In this way, Postural Restoration treatment transforms a downward spiral into a virtuous circle. And this transformation can resolve and heal a host of physical and neurological impairments.