There is an intimate relationship between breathing, posture, and gait.

All three work together and influence each other. Due to the muscular connections involved, any change in one system will impact the other two.

If you change someone’s gait mechanics, the way they breathe will have to change. If someone can’t stand normally due to an injury, their posture will change and so will their breathing.

In reality, breathing, posture, and gait are not different things. Breathing, posture, and gait are three parts of the same system; it’s called being a living, walking, breathing, human. All three systems rely on overlapping musculature that change their function depending on the demands placed upon the body.

Remove normal function of either breathing, posture, or gait, and the entire system becomes something different because muscle function changes.


Breathing involves the exchange of gas within our lungs. Oxygen comes in from the outside, through the nose, down the airway into the lungs, and then gets distributed to our cells.

This oxygen is utilized during normal cellular function to create energy. The leftover waste is used or disposed of by our body in different ways, the most obvious being the exhalation of excess carbon dioxide.

The Body as a Pump

This perfectly normal state of affairs is helped along by a pumping mechanism that occurs completely beneath our awareness.

The human body can be seen as a big pump. All our bodily functions require pumping: breathing, circulation, lymph drainage, digestion, pooping.

Humans have to pump.

About 23,000 and 28,000 times per day our entire body is being moved by the respiratory pumping mechanism.

Upon inhalation–regardless of whether you are resting or moving– the bones of our body have an external rotation movement as the cavities of our body expand to allow air in.

These primary cavities, the pelvis and ribcage, jointly referred to as the thorax, or thoracic cavity, both externally rotate and expand as we inhale. The thorax expands due to the muscular action of the right and left diaphragm and the intercostal muscles.

Expansion of the ribcage decreases inter-thoracic pressure (pressure decreases as a space in a container gets larger) and allows air to move into the lungs.

Upon exhalation, the same bones internally rotate, thereby decreasing the volume of the thoracic cavity. This action expels excess carbon dioxide.

At the end of exhalation, the respiratory mechanism briefly pauses prior to the next inhalation.

This settled internal rotation position is where we should be starting from. It’s the state our body should return to after each breath.

It shows a body that can truly rest.

However, in the left AIC right BC pattern, muscular overactivity prevents this normal breathing process from occurring because it doesn’t allow for normal expansion of the thorax.

Two areas of the thorax stay “closed”, and thus don’t expand, while two areas of the thorax remain “open” and thus never return to that internal resting state.

Humans as Movement

Posture is the position our body assumes in relationship to our surrounding environment.

Posture is a dynamic process. Even if we are standing still, we aren’t actually still, nor completely at rest.

Our muscles still have tension in them as they act against gravity, otherwise we would fall down. These anti-gravity muscles are generally known as our extensor muscles that are located on the posterior aspects of our body, mostly our back.

In addition, our muscles are still moving because breathing never stops. As we already know, normal breathing requires muscular action of the diaphragms and intercostal muscles.

Here’s a different way of thinking about life: Humans aren’t creatures that have the capability to move; humans literally are movement.

Even if we aren’t consciously moving, our bodies are still in a constant state of movement.

Fluids are being pumped, blood is being circulated, cells are dying, being created, and moving around.

All this movement requires muscular action (although not necessarily skeletal muscle contraction).

Posture as Orientation

Posture can be assumed in different positions. Standing is what we classically associate with posture, but we also have seated posture, kneeling posture, lying down posture.

These are all postures and all will require muscular action at some level.

Even the least amount of muscular action– lying down– still requires breathing, and breathing requires muscles.

Posture also demands “orientation” of the human body.

Humans ‘orient” themselves towards something.

The human body has a direction it wants to face. Generally that direction is forward.

But the body, and in particular the head and neck, will orient itself due to sensory perception of the external world.

What you feel, see, smell, and hear will unconsciously cause your body to orient in different directions, all in the desire to answer the question: “what is it?”

What did you hear? What did you see? Where is that smell of Cinnabons coming from?

We orient ourselves, via posture, towards where ever our attention is drawn.

Posture is not simply “stand up straight and shoulders back”.

That idea is based on ignorance of the dynamic nature of bodily positions, positions that are regulated by a brain that is integrating sensory perception of the outside world along with the immediate interests of the human organism of which it is mediating.

Where to go, what to do, and how to do it most effectively. All these variables contribute to posture.

Why Do We Move?

Gait is walking. Walking is movement. To move forward we need muscles and desire. We need a reason to walk.

The ability to move makes food easier to obtain. Food equals energy.

An organism that can move to obtain food has a better chance of survival than an organism that can not, provided that the energy expended in order to obtain the food doesn’t exceed the energy being consumed and energy that can be stored for later use.

This situation will result in impaired function, starvation, and death.

So movement forward doesn’t automatically result in superior energy gathering. It’s based upon the conditions. Sea squirts have done quite well just sitting on the ocean floor waiting for food to pass by.

Humans have to move. We waste away with a lack of movement. Food is no longer difficult to obtain for most of humanity, in the sense that famine is quite rare. Most starvation occurs due to war or governmental policy, not because there isn’t enough food available (see famine: Irish).

Nonetheless, humans move, we must move for optimal health, and that movement requires forward ambulatory upright movement.

Two Bodies, Two Patterns

Let me make it perfectly clear that the right and left sides of the body are not and never will be perfectly balanced, just like the right and left hemisphere’s of the brain aren’t the exact same in structure nor function.

This is not a bad thing. Asymmetry is built into our body. In other words, you are born as a left AIC right BC pattern.

You are built to be right-dominant, regardless of handedness.

To start moving, you have to pick a side. If both sides of the body were completely balanced, how would you pick a side?

There has to be a leader and there has to be a follower.

In humans, the dominant side is the right side. There is more muscle on the right side.

The right diaphragm is considerably bigger and stronger than the left diaphragm.

When We Lose the Left Side

When our perfectly normal left AIC right BC pattern (weight on our right leg) becomes too dominant, that is when problems arise.

It becomes so dominant that we stop using the opposite pattern: our right AIC and left BC pattern (weight on our left leg).

Our left side pattern drops off and we can only use our left side with compensatory muscle activity. We can’t use our left hip and abdominal musculature to stabilize our left side, so we rely on the left hip flexors and lower back muscles.

Difficulties arise when attempting to stand on our left leg during upright activity without using compensatory muscle.

That is when this interplay of breathing, posture, and gait are all affected.

They all depend on one another. So you can’t change your gait mechanics without also changing your posture and breathing. They are all the same “thing” since they are all commanded by the same brain, involve the same muscles, and respond to the same external stimuli.

Once you become compensatory in walking, you have to become compensatory in posture and breathing, too.

It’s all the same musculature.

The degree of compensation is the variable.

That’s what prevents someone doing from what I’m doing in the picture below.

I’m standing on my left leg and touching my right foot while relaxed and breathing.

Gait as Organized Fall and Catch

From a neurological perspective, walking is the rhythmic “falling forward” and subsequent “catch and stabilizing” of the body. One leg at a time.

It’s feed forward, meaning your brain expects to do it again and again, based on prior experience of organized falling.

Fall and catch. Fall and catch.

When those expectations aren’t met, due to stumbling on a rock, or not realizing you have reached the last step in a flight of stairs, your body is in for a rude awakening.

Something unexpected happened and your central nervous system wasn’t prepared for it. You have to stabilize somehow, otherwise you will fall and possibly be harmed. This results in tripping or stumbling, or any type of non-planned, non-gait movement in response to an unexpected stimulus.

Gait is organized and happens unconsciously. We don’t have to think about how to walk. In fact, as someone to think about how to walk and they often start walking incorrectly. They advance the same-side (ipsilateral) leg and arm forward at the same time instead of contra-lateral arm and leg that produces rotation.

Muscular Opposition

During gait, our bones move in opposite directions on top of each other via muscular action. This twisting movement provides muscular opposition. Muscular forces need to be opposed by a counter-balancing force in order to maintain equilibrium and rhythmic gait.

That means that the left side and the right side of the body must oppose each other just enough that a human can walk straight without compensatory muscle activity.

The left and right side need to work opposite of one another.

This opposition is what creates harmony and keeps muscular forces around the midline of our body in balance.

If appropriate muscular opposition is lost, the right and left side no longer act complimentary to each other and we end up with a pattern of one side being more dominant than the other. We call that the left AIC right BC pattern. Prolonged patterned activity leads to compensatory muscle action.

This compensatory muscle action effects muscles that contribute to breathing, posture, and gait. So change one and you automatically change the others.

For better or for worse.

The Muscles


  • Non-compensatory breathing requires muscular action from the diaphragms.
  • Non-compensatory upright postural stability requires resisting gravity, muscular opposition from the other side, and sense of the ground.
  • Non-compensatory walking requires alternating (side-to-side) shifting in the frontal plane.

If we become patterned into the left AIC right BC pattern, we

  • lose the left diaphragm as the pelvis orients right and the left ribs externally rotate. We lose the left ZOA.
  • lose muscular opposition from the left abdominals.
  • lose our left frontal plane as our ability to “sense” the ground on the left is reduced because our bodyweight is stuck to the right.

At this point we become human beings who breathe, stand, and walk with compensatory muscle function.

All muscles on this list change their function depending on position of the pelvis (left AIC pattern) ribcage (right BC pattern) and neck (right TMCC pattern) as they are forced to compensate for our rightward orientated/postured body. 

The Left and Right Diaphragm

The diaphragm is not one muscle. It’s two. That’s shocking to most people, just as it was to me. Every text I’d read referred to it as the diaphragm as if it were one muscle.

Further, left and right diaphragm are different.

The right diaphragm is bigger, stronger, thicker, and has a lower attachment on the spine, which gives it superior mechanical leverage.

The left diaphragm is the opposite. Smaller, weaker, thinner, a higher attachment and thus less mechanical advantage.

Importantly, both diaphragms attach to the lumbar spine, so every time the diaphragm descends (moves down) with inhalation, the pull on the spine is unequal. Over time the pull of the larger right diaphragm orients our lumbar spine to the right.

Where the lumbar spine orients, the pelvis must follow. So we end up, quite naturally, with a pelvis and lumbar spine that “prefer” rightward orientation.

In PRI we call this the left AIC pattern.

As you will now see, this orientation of the lumbar spine and pelvis to the right due to the influence of the right diaphragm will cause some very consistent and predictable compensatory muscular activity that results in altered breathing, posture, and gait.

The impact of the pattern upon the diaphragmatic function is the following:

  • The left diaphragm decreases its role as primary muscle of breathing and increases its role as a postural stabilizer.
  • The right diaphragm continues to work as a primary breathing muscle.

The Hip Flexors

The hip flexors on the left become overactive. The psoas is hypertonic, as is the left diaphragm, due to the anteriorly tilted left hemi-pelvis.

This is only natural considering these two muscles are essentially the same muscle. They are contiguous. You can’t separate them out during dissection.

In addtion, the left TFL is overactive as a femoral internal rotator and the left rectus femoris is hypertonic due to the anteriorly rotated pelvis.

This anteriorly tilted position of the pelvis, and resultant left psoas hypertonicity can result in:

  • anterior weight shift on the left side of the body
  • internal rotation of the left tibia and resultant “fake” pronation of the left foot
  • left knee pain due to twisting: the femur orients in one direction and the tibia orients in the other.
  • a left femur that externally rotates in order to orient straight, so you can walk straight.
  • a lax anterior hip capsule and stretched out ligaments due to prolonged left leg external rotation
  • left SI joint pain due to left hip weakness.

Coincidentally, this is why the psoas does not cause an anterior pelvic tilt or lateral pelvic tilt. The psoas is the victim of the silent perpetrator, the bigger right diaphragm.

On the right side the hip flexors can be tight but for a different reason. They are overused to hold you up in right stance for the loss of right glute strength.

Right glute maximus and medius weaken in left AIC pattern because they are never able to fully push your center of mass to the left. If you don’t use it, you lose it.

The glute weakens in abduction and external rotation, and as a compensatory measure, the right hip flexors will pick up the slack and you may have a right piriformis that tries to be the primary external rotator– a job at which it fails miserably. It’s called right piriformis syndrome.

Compensatory right hip flexor activity will often result in right anterior hip pain and tension.

Quadratus Lumborum

Lower back pain is often felt in the right and left QL. It’s important to realize that once again, the QLs are just victims of a position they’ve been place into. It’s like when someone forces you into a situation that you don’t want to be part of, and it stresses you out.

The QLs say to the right diaphragm, “don’t do this to us, we can’t handle it anymore”.

The non-cooperating right diaphragm goes right ahead and pulls us to the right, and the QLs suffer as a result.

The right QL is placed into a position that it develops hypertonicity in the frontal plane. The right QL should be active in right stance of gait as it helps stabilize the pelvis, spine, and ribcage when our weight is on the right leg.

The right QL should “let go” once our weight is placed on the left leg. But since we are in the left AIC pattern, the pelvis never orients to the left, so the right QL never gets to turn off. It can also get overused in an attempt to “throw” the right arm backwards with shoulder extension during arm swing.

The left QL can also become painful due to the position of the pelvis. However this is more due to the extended (over-arched) position of the lumbar spine on the left as well as the lumbar spines rightward orientation.

As the lumbar spine is pulled into a rightward orientation, and the left hemi-pelvis anteriorly rotates, the left QL gets compromised.

In addition, since the pelvis is constantly be tugged over to the right, we lose left abdominal opposition. The left abs weaken, the left hip musculature–adductors, hamstrings, glute medius– weakens, and the QL likely has to pick up more of the responsibilities for spine/rib and pelvis stabilization.


Once the left ZOA is lost and our left diaphragm ceases to engage as a primary muscle of respiration, we pattern more strongly into the right BC pattern, our right lateral ribs and chest wall become compressed.

This compressed state of our right lateral chest wall interferes with the ability of the right lung to inflate, so our breathing becomes more difficult. If the chest wall can’t expand, how will we get air?

The most common way is to use the neck, in particular the right SCM, to “lift” the entire ribcage straight up towards your ears in a desperate hope to facilitate more airflow.

This is a great strategy when the demands of life increase, like when playing sports. But if you have to utilize ribcage elevation all the time, serious complications arise.

  • right shoulder impingements and right scapular instability
  • tight right intercostal and abs muscles.
  • difficulty breathing
  • Forward head/neck posture.
  • neck pain due to the constant state of neck muscle activity attempting to lift the ribcage up.
  • TMJ/TMD due to the chronic tug of the right SCM on the right mastoid process of the right temporal bone. This tug often shifts the right tempo-mandibular joint forward compared to the left.
  • malocclusion (poor tooth contact). As the right jaw shifts forward, our bite now becomes “off”.
  • headaches due to overactive neck and jaw muscles. Right trapezius, right SCM, right masseter, right temporalis all end up overactive.
  • Thoracic outlet syndrome symptoms due to compression of right chest wall, restricted 1st rib and clavicle.
  • facial asymmetries due to altered temporal bone and sphenoid relationships.
  • Balance issues due to altered position of the inner ear due to temporal bone alignment
  • Changes to the visual system.

Suffice to say, overactive SCMs can wreak havoc on the overall system, but they are not the cause. They just get put into a position that they can’t turn off.


All attempts at resolution must use PRI techniques that seek to re-establish proper position of the pelvis, ribcage, and neck to make us non-compensatory humans.

To do this properly some conditions must be met:

  • All structures must be placed into a leftward orientation
  • A particular phase of gait must be addressed
  • We must breathe appropriately.
  • The neck must stay relaxed.

If these conditions are met we can activate left-sided musculature and inhibit right side musculature.

All told, these techniques

  • Turn “off” overactive hip flexors on both sides.
  • Turn “off” overactive QLs.
  • Turn “off” overactive right SCM.


  • Turning “on” the left hamstring and bi-lateral glutes.
  • Turning “on” the left adductor, left anterior glute medius and left internal obliques to re-build left frontal plane stability.
  • giving you left ground “sense” via placing the left foot on a wall or the ground. This gives you a foundation for alternating side-to-side gait.

All of these things must happen simultaneously because breathing, posture, and gait are all one thing.