The Influence of Breath on the Thoracolumbar Spine

Breath. We take it for granted. We breathe in, we breathe out. We don't have to think about it, it just happens. And yet, breath is the one thing that ties into everything we do. Breath supports posture and acts as the bedrock for the function of every single system in the body. It unites the sympathetic and parasympathetic nervous systems. It connects spirit to form. Outside of ourselves, we can tune into others through breath - without a word being spoken. Perhaps breath deserves a little time and attention after all...

To understand breath, let's start with a some basic anatomy. The diaphragm is the primary respiratory muscle. It is a dome-shaped muscle which attaches to the inner surfaces of the sternum (breastbone), mid-spine and lower ribs (all the way around). These muscle fibres insert on their own central tendon. There is an important and often overlooked "crural" portion of this muscle which arises from the front and sides of the first, second and third lumbar vertebrae, and attaches on the central tendon as well. If the main body of the diaphragm is shaped like a parachute, the crural portion is the ripcord. (When you pull the ripcord on a parachute, the parachute opens. The same action is true for the crura and the main body of the diaphragm.)

It is also important to note that through the crura, the diaphragm has fascial continuity with the psoas major (a deep hip flexor) and the quadratus lumborum (an extensor of the spine). By the nature of its insertion point on the 12th ribs, the quadratus lumborum acts as an accessory in breathing by anchoring the last ribs and consequently, the posterior fibres of the diaphragm. The fascial continuity with the psoas continues on into the pelvic floor and beyond. 

What creates breath? On a purely biomechanical level, the brain registers elevated levels of carbon dioxide in the blood, triggering the reflex to breathe. The muscular fibres of the crura draw the dome of the diaphragm downward on inhalation. As the dome descends, the lungs are filled, and pressure is placed upon the abdominal organs, causing a puffing forward of the abdominal wall. When the deep abdominal wall is toned and resists this puffing, the lower ribs expand and radiate laterally, creating what is often called "breathing into the back" or "bucket-handling" of the ribs. 

Often, in teaching breath, much emphasis is placed on this bucket-handling of the ribs. This articulation of the ribs on the spine is crucial for decompression of the vertebrae. What is often neglected, however, is the movement of the crura along the the front of the spine - the active descent of the diaphragm prior to the laterocostal movement. This descent creates a grounding for the breath. If too much emphasis is placed on the lateral movement of the breath before the diaphragm has made its fullest vertical excursion, then the upper accessory muscles come into play too early, creating inefficiencies and, in my opinion, hypertonicity in the diaphragm itself. 

When good vertical movement of the diaphragm occurs, the fascial continuations into the psoas and the quadratus lumborum, (as well as the multifidus), take on a more important role. When the deep abdominal wall is strong, and the breath can travel down along the front of the spine, an integrating and stabilizing effect is created through the thoracolumbar junction and upper lumbar region. 

Try this simple exercise:

Lying supine, with knees bent and feet flat on the floor, imprint the spine into the floor in a neutral position.

Inhale: Draw the breath into the body along the front of the spine. Visualize the long fibres of the crura insinuating themselves into the upper fibres of the psoas major. Initiate the bucket-handling of the ribs.

Exhale: Feel the lower crural fibres of the diaphragm drawing the top fibres of the psoas major up the front of the spine as the diaphragm relaxes. Relax the ribs, engaging the transversus abdominus (deep abdominal wall) to gently assist the expulsion of air from the lungs. 

Try the same thing in a sitting position. What do you notice? Many people will experience a feeling of length and opening through the thoracolumbar spine, and a widening through the low back. As well, people notice enough decompression in the vertebrae to significantly increase range of motion in rotational movement. In movements requiring spinal flexion or extension, the diaphragm/psoas/quadratus lumborum connection provides stability and facilitates clear segmental movement through the thoracolumbar portion of the spine.

Consider the implications of the connections in support of standing positions, and particularly in gait. The psoas and quadratus lumborum are critical in support of the trunk on the pelvis, and in the transfer of weight through the spine to the legs. In my experience, breath with a strong crural component allows for a clearer connection to the upper attachments of the psoas and the quadratus lumborum, as well as a sense of width to the multifidus. The legs can "hang" more easily from the hips, and the quadratus lumborum can maintain length in walking and running. 

The thoracolumbar junction is the point at which the top and bottom halves of the body are integrated. The sympathetic (fight or flight) and parasympathetic (rest and digest) nervous systems are linked here. Breath connects to gait, spirit connects to form. Through clear intention into the breath, one can release bracing of ribs, spine and pelvis - facilitating a flow of energy to sustain vertical with little effort. The body and mind become better able to respond rather than react. 

So - take a few minutes, explore your breath. Feel its depth, its width, its length. It is a three dimensional movement in the body which can help you do everything else you do with greater ease. Relax your skeleton.. and BREATHE!