Considering we’ll likely take 20,000 breaths today, the understated muscle the diaphragm deserves attention.
“When the diaphragm stops flexing, air stops moving. After four minutes of that, pieces of the brain start to die. Folks who bravely survive muscular dystrophy — a genetic disease in which muscle fibers are unusually susceptible to damage and become progressively weaker — eventually pass away because of the failure of the diaphragm. When snake venom paralyzes all the muscles of the victim, suffocation is the cause of death because the diaphragm, too, is paralyzed.”
Louis Jackson, Yoga Tune Up® Instructor
The diaphragm is attached to lumbar vertebrae 3 and 4, the internal surface of the lower 6 ribs and shares its fascial sheath with the psoas and the quadratus lumborum. The posterior fascia of the diaphragm is contiguous with the lungs and its anterior surface with the ribcage lining and that of the peritoneum. These connections and the action of relaxation after contraction assist in the movement of blood to and from the heart. In fact, being a border crossing for the aorta, inferior vena cava and esophagus, the diaphragm is intricately involved in the delivery of blood to all organs and back to the lungs for reoxygenation. Knowing all this, wouldn’t you prefer to make it 20,000 nourishing daily breaths (instead of 20,000 lousy ones)?
The mechanics of breathing are summarized in the pictorial to the right: inhalation requires the contraction of the diaphragm, however the scalenes, sternocleidomastoid, pectoralis minor, serratus anterior and external intercostals also contract to elevate the ribs and sternum, which enhances diaphragm contraction and lung expansion. Exhalation requires contraction of transversus thoracis, internal intercostals, rectus abdominus, obliques and tranversus abdominus, effectively changing thoracic cavity volume and forcing air out.
The diaphragm is under both conscious and autonomic control – it is necessary for the diaphragm to contract in life and death scenarios (so blood is driven from digestive and reproductive organs to supply the muscles enabling the body to take flight or fight). Our modern lifestyles stimulate frequent (sometimes constant) facilitation of the diaphragm, which is one of the effects of stress on the body. Busy work schedules, less than healthy interpersonal relationships, PTSD, holding our core “in” on the inhale, mindless breath, skipping meals, sleep and schedule irregularities, ignoring emotional stresses and the list goes on… ARE all realised by the body as threats, facilitating the diaphragm and unconsciously stimulating the autonomic nervous system.
When the diaphragm is facilitated, it sets off the cortisol release response. Most of us can recall a surprising or stressful event, a phone call, door slamming loudly where we have literally subconsciously gasped. This stressed diaphragm contraction sets off a chain reaction that effectively shuts down digestion and causes a cascade of hormone reactions that, over time (if diaphragm is often contracted), can be associated with excess estrogen, testosterone and a depletion of progesterone. This hormonal imbalance can lead to menstrual, fertility, and implications on potential to sustain the womb for pregnancy (infertility/miscarriage).
When the diaphragm is facilitated, it also pulls on the fascia of the lungs, which can lead to shallow breathing, impeding the full function of the breath in delivering blood to the heart. Contraction of the diaphragm also pulls on the fascia of the peritoneum (gut area lining), which can impact digestion, bowel function and hormone balance. The myofascia’s of the diaphragm will also be taut from constant contraction. This can negatively influence the psoas and quadratus lumborum QL, who share its fascia and attachment points.
Apart from the stresses of modern life triggering its facilitation, the diaphragm cannot fully relax if there is constant tension in the iliopsoas, psoas, iliacus, quadratus lumborum, esophagus, and lungs which cross through it/share its fascia. In addition, peritoneal cavity organ disorders or adhesions (rampant due to high number of appendectomy, GB removals, hysterectomies, c-sections, bowel surgeries, estrogen dominance and endometrial growth etc) can pull on fascia causing diaphragm contraction and/or impeding relaxation.
In my 15 years of naturopathic practice, I have seen a big rise in cases of all the above, meaning most of my new clientele walk in mostly unaware of their overstimulated autonomic nervous systems and less than optimal diaphragmatic function.
The great news is that the diaphragm is under both conscious and autonomic control, which is where Yoga Tune Up® shines with tools to relax this incredible muscle. Relaxation of the diaphragm helps to increase the dominance of parasympathetic nervous system due to its close relation to the phrenic nerve (and minimising the risks outlined previously outlined).
Stay tuned for my favourite YTU tools (with videos of exercises) to down regulate your nervous system and relax your diaphragm in my next article!