One of the biggest misconceptions about posture is that "poor posture" is caused by stiff and weak muscles.

There is far more to the story than that.

In fact, I believe that the muscle's influence on posture is a reaction to other factors; both external and internal.

In this article, we're going to discuss:

• What really causes swayback posture
• Common assessment measurements
• Exercises to improve swayback posture

Before moving on, if you'd rather watch the full video you can watch it below: 

 Factors That Impact Muscles

As I mentioned above, there are many things that will impact posture.

Some of which include:

• Gravity
• Centre-of-mass
• Ground reaction forces
• Repetitive motions
• Internal pressure (breathing)
• Previous injury
• Limited mobility at a specific joint
• Visual and vestibular
• Cardiovascular flow 

And many others.

Notice how I didn't include muscles?

Muscles will react to the factors on that list.

Pretend I put a bar on your back as if you were to do a back squat. 

Your centre-of-mass would shift forward towards your toes. Your body is reacting to the bar pushing you forward which then would cause certain muscles to contract.

Now instead of a bar, we have gravity. Gravity is a force that constantly trying to push us into the ground (just like the bar) so we need to push up against it.

If we don't have certain mobility at the foot, knee, hips, ribcage, shoulder etc, then we will shift our centre-of-mass towards our toes because its easier to put force into the ground.

This is when you start seeing arched lower back, flared ribs, hyperextended knees, collapsed feet and squeeze shoulder blades.

Swayback Posture

In my EVOLVE Biomechanics Mentorship, I discuss how posture is a reflection of our body moving in order to resist gravity, ground reaction forces (forces from the ground otherwise we would fall through it) and internal pressure (breathing, organ movement). 

As I mentioned, if we don't have the movement in our lower body, specifically internal rotation, then our centre-of-mass (COM) will shift forward to put our joints in an easier position to push off the ground and extend the hip.

Now let's say your body has used the above strategy of tilt the pelvis forward and flaring your ribs (if you try it on yourself you can feel your body shift forward) and still, it needs to put more force into the ground, it isn't able to push anymore forward otherwise you'd fall on your face.

Now what happens is you will round your shoulder forward, and push your head forward.

The rounding of the shoulders happens because the scapula (shoulder blades) come up and over your ribcage and push the shoulder down and forward.

It would be similar to someone taking their hands, putting them on your shoulders and pushing down.

Now because you would fall on your face if you go anymore forward, you collapse your chest to keep yourself back and round the shoulders and push the head forward again to put force into the ground.

It starts by me standing behind you and pushing you forward (flared ribs). You then need to stop yourself, so I run super fast in front of you and push you back from your chest. Then I run behind you, jump on a chair push your shoulders down and push your head forward.

Voila, you now have a swayback posture.

Seems complicated doesn't it?

It is and it isn't. The COM game makes it easier to fixing the root cause of the issue rather than stretching a bunch of muscles that are hanging on for the ride.

Impact on Assessment Measurements

With the COM so shifted forwarded on the toes with a swayback posture, tissues are going to be maximally stiff because the joints are hanging out at their end range of motion.

This is why you're going to see an exaggerated limitation in almost every measurement:

• Straight Leg Raise you're going to see below 45 degrees.

Hip flexion below 90 degrees

It's also not uncommon to see a pooch in their belly because their pelvis is pushed so far forward that their guts are "falling out of the bucket (pelvis")

Essentially you'd expect almost every movement to be very limited.

How Do We Improve It?

Understanding it is one aspect, knowing how to address it is another. 

To address it, we have to reverse engineer how the body got there in the first place.

As I mentioned, we have a ribcage and a pelvis that is being compressed from the front and the back.

I like to use a water balloon analogy to illustrate this:

You may be able to see that in this photo, if I squeeze the water balloon (i.e., pelvis/ribcage) front and back, the balloon will expand side-to-side.

This means that there isn't a lot of room to perform shoulder/hip flexion and extension, but I do have room to move laterally.

To address this we need to expand front-to-back, shift the centre-of-gravity back while reducing the tension of the rectus that is pulling the ribcage and pelvis together at the front.

Exercise #1: Modified Oblique Sit

 This is one of my favourite movements to start with as it accomplishes everything we just discussed. (Of course, I use many different exercises as it depends on the person but this is one I have definitely used many times).

We are lying on our side, and beginning to use muscles like our external obliques to close the ribcage down and reducing tension on the 6-pack. 

 Exercise #2: Modified Crawling

 Now that we have decompressed the ribcage side-to-side, its time to teach the body how to shift the centre-of-gravity back. 

The leg out towards the side is going to be used if there is some sort of rotation of the pelvis.

Exercise #3: Sidelying Cable Traction

This is another sidelying exercise but slightly different than the modified oblique sit.

By using the cable, we are able to now create some space in the shoulder joint while reinforcing the above.

Swayback posture isn't caused by tight muscles but a dynamic interplay between many systems and a centre-of-mass game.

If you want to learn more about how to address compensations like this, then join my EVOLVE Biomechanics Mentorship !