The Case for the 3-D Diaphragm

There is no question that teaching people the efficient use of the
diaphragm is very important.  Problems arise, however, when the action
of the diaphragm is viewed in the limited context of its effect on
movements in only the abdominal region of the body. This action, often
referred to as “belly breathing” represents only one dimension of the
increase in volume that the diaphragm creates in the thoracic cavity;
the vertical. I will explain how the diaphragm is capable of increasing
all three dimensions of the thoracic cavity, namely: the vertical
(top-to-bottom), the transverse (side-to-side) and the sagittal
(front-to-back).

What are the problems that arise from this limited perspective?

Many people who teach and learn abdominal breathing determine the
quality of their breathing only by its location in the torso, i.e.:
abdominal movement is good, thoracic movement is bad.  This ignores the
critical issue of effort.  It is possible (indeed, quite common) to do
tense belly breathing, just as it is possible to do relaxed chest
breathing.  In addition, this top/bottom distinction is only
one-dimensional, as it ignores important lateral and sagittal breath
movements .

By equating abdominal shape change with diaphragmatic breathing and
thoracic shape change with accessory (non-diaphragmatic action), a
false distinction is perpetuated between diaphragmatic and
non-diaphragmatic breathing. ALL breathing is diaphragmatic (except in
cases of paralysis, such as quadriplegia).  It is untrue and damaging
to suggest to someone who predominantly exhibits thoracic shape change
that they are not using their diaphragm.  They are using it
inefficiently, and perhaps in combination with many other unnecessary
muscles, but they are certainly using the diaphragm.

By accepting abdominal breathing as “correct,” learning and
automatizing the habit, the breathing mechanism becomes less adaptable.
Being stuck in any pattern will create problems, regardless of how
useful that pattern may be in a given context.

Please keep in mind that it is not my intention to negate or disparage
the enormous benefits that derive from leaning the conscious use of the
diaphragm thru abdominal breathing.  It is my intention to literally
bring a more three-dimensional approach to the field of breath
training .

Breathing as Shape-Change

To clarify this perspective on the breath, it will be useful to clearly
define what I mean by breathing.  In the context of this argument, the
term breathing is being limited to the mechanical act of increasing and
decreasing thoracic volume; in other words, inhaling and exhaling.

A useful definition for breathing is: “The shape change of the thoracic
and abdominal cavities.”   Both cavities – by definition – must change
shape in the act of breathing; the diaphragm is the floor of one and
the roof of the other.  There is, however, a significant difference in
how the two cavities change shape in the act of breathing. The thoracic
cavity – like a bellows – changes its shape and volume, while the
abdominal cavity – like a water balloon – changes its shape, but not
its volume.  This is why it is misleading to describe an abdominal
breath as an “expansion” of the belly; it is actually a bulging of the
abdomen, who’s contents are non-compressible or expandable. This is in
the context of breathing only; in the context of other life-processes,
the abdominal contents will of course fill and empty, thus changing
their volume. It should be noted though, that any increase in abdominal
volume will require a decrease in overall thoracic volume.  This is why
it is temporarily harder to breathe “on a full stomach” and chronically
harder to breathe if you are obese or pregnant.

The muscles that control the shape change of breathing are usually
categorized as “muscles of inspiration” and “muscles of expiration.”
This can be confusing, since some “exhaling” muscles can be quite
active during an inhale, and vice versa.  I prefer to categorize the
muscles by their effect on thoracic volume; there are muscles that act
to increase thoracic volume (principally the diaphragm), and there are
muscles that act to decrease thoracic volume (primarily the abdominals
and internal intercostals).

Accessory Muscle Action

Muscles other than the diaphragm that can increase thoracic volume are
commonly referred to as accesory muscles of inspiration, and these
include the external intercostals, the scalenes, the
strenocleidomastoids, the pectoralis minor, the serratus anterior, and
others that must work to stabilize them.

There are no accessory muscles of thoracic volume reduction due to the
fact that they are ALL accessory to the passive elastic recoil that
produces exhalation in a relaxed state.

Of the accessory muscles, the external intercostals are most important
to understand.  Although the diaphragm is capable of expanding the
ribcage without their help (see below), they are frequently involved in
thoracic breath movements.  It has been argued that ANY intercostal
muscle – because of its location between the ribs – is incapable of
expanding the ribcage by virtue of the fact that muscles can only
shorten; therefore it would be obvious that a shortening muscle lying
between the ribs could only draw those ribs closer to each other in an
exhalation.

The above argument would hold up if it were not for the fact that the
space between the ribs actually remains constant during all phases of
breathing, and the changes in volume of the ribcage are brought about
by the SLIDING of the ribs in relation to each other during
respiration.  The intercostals, being arranged in perpendicular layers
oblique to the direction of this rib sliding are, in fact, ideally
suited to assist in respiratory movements.

How the Diaphragm Expands the Ribcage in 3-D

A closer look at how the thoracic cavity changes its shape reveals
several facts:

The best-known fact is that the contracting muscular fibers of the
diaphragm pull the central tendon downward, lowering the floor of the
cavity, thus increasing its vertical dimension.  This is a description
of the famous “abdominal breath.”

A lesser-known fact is that the contracting fibers of the diaphragm
pull the base of the ribcage upwards, causing the ribs to hinge at
their costovertebral articulations, thus increasing the transverse and
sagittal dimensions of the thoracic cavity.  This is why it is correct
to say that the diaphragm creates three-dimensional expansion of
thoracic volume.

Like many muscles, the diaphragm can move its insertion towards it
origin (central tendon towards base of ribcage), or its origin towards
its insertion (base of ribcage towards central tendon).  It’s all a
question of which end of the muscle is mobile, and which is stable.
From this perspective, a belly breath is the result of stabilizing the
diaphragm’s origin and mobilizing its insertion, while a chest breath
is the result of stabilizing the diaphragm’s insertion and mobilizing
its origin.

The Unobstructed Breath

Of course, it’s possible to release all of the diaphragm’s stabilizing
muscles, and allow its origin and insertion to freely move towards each
other. This is the definition of an “unobstructed breath.”  This rarely
occurs, as the need to stabilize the body’s mass in gravity will cause
many of the respiratory stabilizing muscles to remain active through
all phases of breathing.  The goal of breath training (on a planet with
gravity anyway) is create the most efficient (least obstructed)
postural/breath patterns possible in an ongoing context of body
position/movement and effort/intention.

Since the diaphragm, in an unobstructed state, will create 3-D shape
change in the thorax, intentionally isolating that shape change in the
abdominal region requires one to block the other dimensions of
movement.  In other words, abdominal breathing requires the contraction
of the muscles that restrict rib movement.  Furthermore, it also
requires the relaxation of the abdominal wall. By persistently
breathing in this pattern, one will develop a chronic tightness in the
thoracic structures that support the shoulder girdle and head, as well
as a chronic weakness in the abdominal wall, which provides support for
the lower spine.  In short, habitual abdominal breathing interferes
with effective postural support. It is precisely this action of
disengaging postural support that can make abdominal breathing useful
for supine relaxation (if it’s done in a non-tense manner).
Significant problems will arise if that pattern persists upon standing
up, for the breath will be prevented from adapting to the demands of
vertical support.

The Emotional Connection

It should be noted that the pattern described above also limits
emotional flexibility, as it habitually reduces the sensory perception
of space and movement within one’s chest and abdomen – the metaphorical
“heart and gut centers” we all seem to need more connection with.  In
short, although belly breathing may reudce some stress symptoms in its
practitioners, getting stuck in that pattern presents the very real
possibility of reinforcing one’s emotional defense mechanisms.

Think of what you do in your belly to protect yourself from a punch;
now picture doing that more or less all the time on a subtle,
subconscious level.  Now picture moving that tension forward and back
as you breathe, and you’ll understand how many people do their
abdominal breathing without ever really releasing the underlying
tension.

Yoga

In a fundamental way, this relationship of breathing patterns to the
critical issues of support and release forms the methodological basis
of yoga practice.  Breath and posture are different ways of viewing the
same thing.

Breath is how we move space through ourselves, and posture is how we
move ourselves through space.  Or, breathing is about changing the
shape of our body cavities, and posture is about maintaining the shape
of our body cavities.

This perspective is clearly expressed by Patanjali in the second
chapter of the Yogasutra when he defines asana practice as
Sthirasukhamasanam:  Sthira (stability) and Sukha (ease) are the dual
qualities of Asana (yoga posture).

Another take on Sthira and Sukha relates those terms to the exploration
- on all levels – of the healthy relationship between boundaries and
space. This includes our sensory, emotional, intellectual and spiritual
spaces – but it all starts with getting the physical spaces to
cooperate in a harmonious way.