Anatomy of breathing
By Rachel de Simone, PT, DPT
Breathing is typically an automatic process that happens without thought or conscious control. However, the breath is the only autonomic process you can choose to control through voluntary action. By changing the way you breathe, you can influence your heart rate, nervous system, posture, and the flow of energy in your body.
The diaphragm is the main muscle of inspiration. It rests like a dome at the bottom of the rib cage. When you inhale, the diaphragm pulls down and expands the volume of the lungs and ribs. When you exhale, the diaphragm relaxes back to its resting state. A relaxed exhale requires very little effort, as it is the result of the passive recoil of the diaphragm. However, the abdominal muscles can assist with facilitating a deeper exhalation by narrowing and depressing the rib cage. 
The efficiency of the diaphragm is deeply connected to the alignment of the rib cage. When the ribs are stacked above the pelvis, the diaphragm rests in its natural state, and has room to move. When the ribs are in a flared or displaced position, the diaphragm gets stretched out and no longer has the full excursion available to enable deep inhalation. As a result, the neck muscles attempt to assist with breathing in by elevating the upper ribs. This leads to neck and shoulder tension, and can limit shoulder mobility by changing the way the shoulder blade sits on the rib cage. 
This also results in inhibition of the automatic engagement of the core, leading to postural instability. Think of the game Jenga. When all of the blocks are aligned, the tower is pretty stable. However, if any of the blocks are pulled out of alignment with the tower, it is no longer as stable. The same is true for the body. When the rib cage is out of alignment with the pelvis, the posture is not as stable, the diaphragm begins to be used for postural stability, and breathing becomes shallow and strained.
Breathing is the most important function in your body as all of your cells and organs need oxygen in order to survive. The consequence to inefficient respiration is a negative feedback cycle in which we begin to over-breath, and rarely fully exhale. Most importantly, it creates stress on the nervous system and puts the body into fight or flight mode. Inefficient breathing can lead to headaches, anxiety, pelvic floor dysfunction, vocal cord dysfunction, neck and back pain, shoulder pain, and other physical issues. To counter this, breathe through your nose and lengthen your exhalations relative to your inhalations. You can work up to a 2:1 ratio in which you exhale for twice as long as you inhale. Lengthening your exhalations will help calm your nervous system, and engage your core muscles to help you feel more centered. 
This is one of my favorite subjects, and I’m excited to be teaching an “Anatomy of the Breath” workshop at Evolution on Saturday, February 22nd from 1 – 3 pm. I’ll be teaching about the connections between posture, alignment, breathing, and core stability, and the importance of exhaling. For more information and to register, visit:
Additional resources: 
Soothe Your Nervous System with 2:1 Breathing, by John Clarke, MD
The Oxygen Advantage, by Patrick McKeown:
Dr. Rosalba Courtney’s research:

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