The 5 Hidden Truths of Your Diaphragm: Beyond Breathing to Core Stability

By Nisarga Eryk Dobosz · 9 February 2026

As a MER® and BBTRS® therapist, I spend my days listening to the body’s language. It speaks through tension, breath and the intricate relationships within the fascial web. And in this dialogue, one structure emerges again and again as the quiet, central orchestrator: the diaphragm.

Most people think of it simply as the “breathing muscle”. But in the world of fascia, biomechanics and holistic function, that is like calling the conductor of an orchestra just the person who waves a stick. The diaphragm is your body’s intelligent core architect. It plays a part not just in breathing, but in stability, spinal health and emotional regulation.

Let’s explore five things you might not know about this humble dome of muscle and fascia.

1. It’s your primary internal stabiliser

The anatomy: the diaphragm is a parachute-shaped muscle with a central tendon, anchored to the inner surface of the lower six ribs, the sternum and, crucially, the lumbar spine via two fibrous “crura”.

The science: with every inhale the diaphragm contracts and descends. This does more than draw air into the lungs. It pressurises the abdominal cavity, creating intra-abdominal pressure (IAP). Think of your torso as a sealed, fluid-filled cylinder with the diaphragm as the piston at the top. Its downward movement increases pressure inside, creating a firm yet dynamic support column that stabilises the spine from the inside out.

Why it matters: this makes the diaphragm a key player in true core stability, working together with the deep abdominals and the pelvic floor. When it moves freely, it gives 360-degree support that allows powerful, graceful movement. When it is held or under-used, the outer “core” muscles tend to over-grip, which can contribute to stiffness, back discomfort and inefficient breathing.

2. It works in synchrony with the pelvic floor

The anatomy: at the base of that pressurised cylinder sits the pelvic floor, a muscular sling often called the “second diaphragm”.

The science: for good core function, the two diaphragms move in a coordinated piston-and-cylinder rhythm. On a healthy inhale the respiratory diaphragm descends and the pelvic floor yields, descending and widening slightly to receive the pressure.

The MER® perspective: in our tensegrity-based model the body is one continuous fascial net. The thoracolumbar fascia acts as the “back wall” connecting the two diaphragms. When they lose their coordination, often after trauma, surgery or long-term stress, the whole system falters. The psoas and quadratus lumborum, key postural muscles embedded in this web, then become overburdened, trying to make up for missing central support.

3. A full exhale gently lengthens your lower back

The anatomy: the diaphragmatic crura anchor firmly to the upper lumbar vertebrae (L1–L3).

The science: during a complete, relaxed exhale the diaphragm domes upwards into the chest. As it rises it creates a gentle upward pull through these fascial anchors, which can give the lumbar spine a little more space and allow freer glide of the tissues around it.

Why it matters: with a lot of sitting and stress, which favour shallow upper-chest breathing, many of us live in a state of incomplete exhalation. The diaphragm stays partly descended and this natural, rhythmic lengthening is lost, which can add to a stiff, compressed feeling in the lower back. Teaching clients to exhale fully is one of the foundational tools in MER®.

4. It is intimately connected to the psoas

The anatomy: the diaphragm and the psoas major are fascial neighbours. The medial arcuate ligament of the diaphragm literally bridges over the psoas as it emerges from the lumbar spine.

The science: through this shared fascial bed, tension communicates directly. When one tightens, the other is affected. In an anterior pelvic tilt, for example, the psoas can become chronically shortened, and this tension can draw the crura downwards, holding the diaphragm low and contracted, even at rest. That compromises both breathing and stability.

The MER® principle: this is why we never work in isolation. You can’t truly release a tight psoas without addressing a restricted diaphragm, and vice versa. They are two players in the same myofascial continuity. My work is to unwind these shared patterns and invite both back to a neutral, responsive length where they support rather than strain each other.

5. It has two halves with different roles

The fact: it is more accurate to speak of two hemi-diaphragms. The right and left sides are connected by the central tendon but are distinct.

The anatomy and science: the right hemi-diaphragm domes higher, pushed up by the liver beneath it. The left sits lower and flatter, over the stomach. This asymmetry is part of the body’s design. Fascial restrictions, for example after abdominal surgery, can reduce the mobility of one side, and the rest of the body then has to adapt with compensations and uneven breathing patterns.

Breathing is the first movement

In MER® we see breath as the first and most fundamental movement pattern, and the diaphragm is the maestro of this pattern. When it is free, synchronous and balanced, it orchestrates stability, fluid movement and a calm nervous system. When it is held or restricted, the whole body sings a little out of tune.

My work is to listen to that song. By gently releasing fascial restrictions around the diaphragm, at its rib attachments, its lumbar anchors and its relationships with the organs, we don’t just “improve breathing”. We help restore the centre of the core and give the spine room to breathe. You can learn this work in our MER® training, and explore the breath side of it in our BBTRS® training.

Remember, your next full, conscious breath is not just taking in air. It is engaging your most intelligent stabiliser, gently massaging your organs, giving your spine space and setting the tone for your whole being.

Nisarga Eryk Dobosz is a bodyworker and trainer (BBTRS®, MER®, BCST, Lomi Lomi) and founder of the Body Awareness Institute. This article is for education and self-care. It is not medical advice and does not replace care from a doctor or therapist. It was first published on nisarga8.com.