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Breathe Well and Breathe Often Part 3: The Importance of Big “D”

Breathe Well and Breathe Often Part 3: The Importance of Big “D”

Robert “Skip” George, D.C., CCSP, CSCS

As a personal trainer, you have a unique opportunity to positively affect the lives of your clients by bridging the gap between rehabilitation and fitness.  In fact, every session with your clients needs to have a combination of both if you want to excel in what is becoming one of the fastest growing professions in the world.

In part two of “Breathe Well and Breathe Often”, I mentioned that the diaphragm, or “Big D”, was the most important muscle used in respiration while being intimately connected to the lumbar spine , gait and every neuromuscular function of the body.  As an exercise professional, being able to spot and correct breathing dysfunction may be one of the most important gifts you can provide to your clients.

To be human is to be asymmetrical.  All of us are born asymmetrical yet we are also born with neuromuscular and anatomical features that balance those asymmetries and provide structural homeostasis.  It is when those asymmetries become excessive that they cause dysfunction and pain.

Think about it.  We come standard issue with a liver residing on the right side of our abdomen.  In our thoracic cavity on the right side, we have three lobes of the lung.  On the left side we have two lobes where the heart and aorta reside.  The diaphragm has leaflets on the right and left side  composed of muscular “crura” and is prone to be more domed shaped on the right in part because of the liver below.  In addition, the right side has stronger, deeper and lower crural attachments to the anterior lumbar bodies by 1 to 1 ½ levels than the left.  The leaflet of the left side is much smaller and as a result the abdominal musculature on the left tends to be weaker.  (1)

This asymmetry of lower lumbar attachment of the right leaflet is partially balanced on the left by a muscle behind the lower third of the sternum, back of the xiphoid and costal cartilage of ribs 2-6 reaching up one rib level higher on the left known as the “transversus thoracis”.   Human beings, regardless of dominant hand, have an orientation of the thoraco-abdominal region to the right because the thicker and bigger crura of the right leaflet pulls our spine and torso in that direction.  One of the ways we offset this orientation is with neuromuscular activation of the anterolateral abdominal wall during all phases of respiration. (1,2)

As Ron Hruska states, “The diaphragm’s mechanical action and respiratory advantage depends on its relationship and anatomic arrangement with the rib cage.”   This begins to describe the functional domed shape of the diaphragm called the “zone of apposition” or (ZOA).  Imagine if viewed from the side the thoracic cavity with a big “question mark” that portrays the diaphragm.   The front end is attached inside the sternum and anterior ribs, arching up and back to create the top or dome of the question mark before angling back down to connect to the lumbar spine. (2)

This healthy domed shaped diaphragm is needed not only for breathing but proper function of all the polyarticular muscle chains of the body.  A balanced ZOA on both sides of the diaphragm provides optimum exhalation and inspiration on left and right sides of the thorax with nearly equal contraction and expansion of the rib cage.  This occurs with coordinated activation of the diaphragm and anterolateral abdominal wall working in a balanced and harmonious manner.  If there is weakness or decreased activity of the abdominal muscles, respiration and stabilization will be compromised. (1) And as McGill has eloquently stated, if there is a choice between respiration and stabilization, the NMS will always prioritize breathing.

Dysfunction occurs over time when either side of the diaphragm loses its ZOA and stays more flat or contracted allowing the lower anterior rib cage to “flair”.   This flair causes more convexity of the left lateral chest wall and rib cage and in part closes down the right side of the chest wall inhibiting full inhalation on the right as a result of partial exhalation on the left side.

In chiropractic, we often talk about the issue of “tone”.   A dysfunctional  flat diaphragm, especially on the left side, is a good example of too much tone or chronic contraction.  This excess in tone inhibits full exhalation on the left because the diaphragm is not relaxing into a domed shape and not fully deflating the lungs.  In addition, the anterolateral abdominal wall lacks the ability to hold the anterior ribs in a more functional inferior position thereby maintaining the ZOA of the diaphragm.  The absence of abdominal wall function allows rib “flairing” with excessive external rotation of the ribcage on the left side with internal rotation on the right.  Airflow in general moves more easily into the left chest wall because of the rotational influence of the ribs caused by anatomical asymmetries that become more pronounced over time. (2)

Remember Janda’s “lower crossed syndrome”?  This rib flairing combined with lumbar hyperlordosis is in large part a consequence of weak abdominal muscles especially on the left side.  Add too much tone in the diaphragm on the left with too much tightness or tone of the lumbar extensors and you then have a potential garden of chronic dysfunction and pain.   Hello headaches and neck pain if this dysfunction persists when muscles like the SCM and scalenes are used inappropriately to raise the thorax and shoulders just to get enough air into the lungs.  If you have athletes that you rehab or train this combination of dysfunction will bleed power and performance while leaving them more susceptible to injury!

Starting to get a picture of what occurs with excessive asymmetry?  Sure, the diaphragm is used for breathing but with one side being more muscular and bigger on the right side it now begins to provide an excessive force to one side of the spine affecting the entire torso and gait as well communicating dysfunction through all of the polyarticular chains.  Just because it is bigger and more muscular on the right side doesn’t mean it is working at its full potential.  It can’t until the left side of the diaphragm and abdominal wall is activated starting with full exhalation then restoring a balanced and functional breathing pattern to both sides through retraining the diaphragm and abdominal muscles. (1,3)

The point is that we need to restore a balanced zone of apposition (ZOA) on both sides of the diaphragm especially on the left which tends to get lazy with shallow exhalation and has inadequate abdominal activation during all phases of respiration.  To do this we need to activate the abdominal wall starting with full exhalation thereby maintaining position of the ribcage that is not flared while breathing in (especially on the left side) and expand the lungs and chest wall on the right side while providing for more internal rotation of the ribs on the left side with more external rotation on the right side providing a more balanced skeletal  orientation and do it with one exercise!  Right!

This is where the value of blowing up a balloon comes in handy as described by Boyle, Olinick and Lewis.  One of the best therapeutic exercises for this can be described as a 90/90 bridge with a ball and balloon.  The following are a list of instructions developed by the Postural Restoration Institute.(3)

1. Lie on your back with your feet flat on a wall and knees and hips bent at a 90/90-degree angle.

2. Place a 4-6 inch ball between your knees.

3. Place your right arm above your head and a balloon in your left hand.

4. Inhale through your nose and as you exhale through your mouth, perform a pelvic tilt so that your tailbone is raised slightly off the mat.  Keep lower back flat on the mat.  Do not press your feet into the wall, instead pull down with your heels.

5. You should feel the back of your thighs and inner thighs engage, keeping pressure on the ball.  Maintain this position for the remainder of the exercise.

6. Now inhale through your nose and slowly blow out into the balloon.

7. Pause three seconds with your tongue positioned on the roof of your mouth to prevent airflow out of the balloon.

8. Without pinching the neck of the balloon and keeping your tongue on the roof of your mouth, inhale again through your nose.

9. Slowly blow out as you stabilize the balloon with your left hand.

10. Do not strain your neck or cheeks as you blow.

11. After the fourth breath in, pinch the balloon neck and remove it from your mouth.  Let the air out of the balloon.

12. Relax and repeat the sequence 4 more times.(3)

This is one of many effective exercises that can be utilized to restore the ZOA and functional breathing patterns.  Since breathing patterns are closely linked to musculoskeletal pain and spinal alignment problems, chiropractic adjustments are a natural for this combination of treatment modality along with soft tissue work on trigger points associated with breathing dysfunction. 

If during any of part of this exercise your client experiences pain, light headedness or any other symptom you determine as suspicious, simply discontinue its use.  As always, use your best judgment when applying any corrective strategy.


1. Postural Respiration: An Integrated Approach to Treatment of Patterned Thoraco-Abdominal Pathomechanics, Course Notebook

2. Zone of Apposition (ZOA), ZOA Position and Mechanical Function,    Ron Hruska, MPA,PT

3. The Value Of Blowing Up A Balloon, North American Journal of Sports Physical Therapy, Volume 5, Number 3, September 2010, Boyle, Olinick, Lewis

Robert “Skip” George, D.C., CCSP, CSCS owns La Jolla Sport and Spine in California where he integrates chiropractic, rehabilitation and sport performance training.  He is a certified Functional Movement Screen Instructor and lectures on sports and chiropractic related topics. He can be reached at