Posture — What ItReallyIs (Part 1)
The uncomfortable truth about posture
Let’s get this out of the way early: posture is not a position.
Not “shoulders back.”
Not “chin tucked.”
Not “pretend there’s a string pulling you to the ceiling like a human puppet.”
After 20+ years working in health—helping people crawl out of pain caves and into something resembling normal life—I can tell you this:
Posture is a reflection, not a command.
It reflects what your body:
can feel
can move
can tolerate
And more importantly… what it can’t.
So what is posture, really?
Here’s the version you won’t find on a laminated clinic poster:
Posture is your nervous system’s best guess of where to place you, based on what it understands about your body.
If your brain doesn’t trust a joint…
If it can’t “feel” a region properly…
If movement in an area is about as familiar as a tax return in ancient Latin…
It will avoid it.
It will work around it.
It will reorganise you.
That reorganisation?
That’s what we call posture.
The nervous system: the ultimate control freak
Your nervous system isn’t interested in aesthetics.
It doesn’t care if you “look good” in a mirror.
It cares about:
safety
efficiency
predictability
Research backs this up. Postural control is largely driven by sensory input—proprioception (your body’s sense of position), visual input, and vestibular information (balance) (Shumway-Cook & Woollacott, 2017).
If those inputs are unclear or incomplete, the system does what any slightly anxious manager would do:
It simplifies things.
It reduces movement options.
It locks down variability.
Which is great for short-term survival…
…but not so great for long-term movement or pain.
Movement = information (not just exercise)
Here’s where most people get it wrong.
They think movement is about:
stretching
strengthening
“activating your glutes” (because apparently they’ve all gone on holiday)
But movement is actually:
information for your nervous system
Every time you move:
joints send signals
muscles provide feedback
tissues load and unload
your brain updates its internal “map” of you
This internal map—your body schema—is what allows you to move without thinking (Proske & Gandevia, 2012).
If a part of you doesn’t move?
It slowly gets removed from the map.
Like that friend who stopped replying in 2016.
The less you move, the less you exist (to your brain)
Dramatic? Slightly.
True? Very.
If a joint or region:
doesn’t move through its ranges
isn’t loaded
isn’t explored
Your nervous system loses clarity around it.
And when that happens:
It doesn’t integrate it into your overall movement strategy.
Which means other areas pick up the slack.
Which means…
Hello compensation patterns.
The spine: your body’s shape-shifting centrepiece
Now let’s zoom in on the star of the show—the spine.
You’ve got three main regions:
Lumbar spine → influenced by the pelvis
Thoracic spine → influenced by the ribcage
Cervical spine → influenced by the skull
Each one is layered into the system like a stack of moving parts.
And despite what Instagram might suggest, the spine doesn’t just “stay neutral.”
It moves. Constantly.
In three main ways:
1. Flexion & Extension
Forward and backward tilting.
2. Side Flexion
Left and right bending.
3. Rotation
Left and right twisting.
Simple enough on paper.
But here’s where it gets interesting…
The magic is in the combinations
The spine rarely moves in isolation.
Real movement is messy (in a good way).
It combines:
a - flexion + left rotation + side bending right
b - flexion + right rotation + side bending left
c -extension + side flexion right + rotation right
d -extension + side flexion left + rotation left
These combinations are what allow you to:
walk
run
reach
rotate
exist without falling over
And when these combinations are missing?
The system gets… creative.
(Not always in a way you’d enjoy.)
Walking: the ultimate posture test
You can lie on a table and look “perfect.”
But the moment you start walking?
Game over.
Walking is where posture reveals itself.
It’s the one thing you do:
thousands of times a day
without thinking
under load
through constantly changing conditions
Which makes it the perfect assessment tool.
What your spine should be doing when you walk
Let’s break this down without turning it into a biomechanics PhD.
When your right heel hits the ground (initial contact):
Your spine should:
flex slightly (tilt forward)
side bend left
rotate right
This creates a shape that prepares your body for the next phase.
As your foot moves toward the big toe (loading phase):
Your spine transitions to:
extension (tilting backward)
side bend toward the front foot
maintain rotation
So your body literally reshapes itself as your foot reshapes.
Foot changes → spine changes
Spine changes → whole-body changes
It’s a full-body choreography.
Not a static pose.
Then… reset
As you move through mid-stance:
The spine returns toward neutral
The system reorganises
Ready for the next step
And this cycle repeats… about 6,000–10,000 times a day.
No pressure.
Why this matters (beyond sounding clever at dinner parties)
Your spine isn’t just moving for fun.
It’s doing jobs:
absorbing force from the ground
transferring energy through the body
facilitating fluid movement (blood, lymph, cerebrospinal fluid)
coordinating with breathing and organ motion
Research supports this idea of the spine as a dynamic system involved in load transfer and energy distribution during gait (Bogduk, 2005; Schache et al., 2002).
When movement is limited:
force gets stuck
load is redirected
something eventually complains
(Usually loudly.)
So… what is posture again?
Let’s bring it home.
Posture is your body’s current strategy for dealing with gravity, movement, and load.
It’s shaped by:
what you can move
what you can’t
what your nervous system trusts
what it avoids
It’s not fixed.
It’s not permanent.
It’s not something you “hold.”
It’s something you express.
The real goal
When I look at posture, I’m not asking:
“Are you straight?”
I’m asking:
Can each part move?
Can it adapt?
Can it respond to load?
Does the system integrate it?
Because here’s the kicker:
Change one part, and the whole system has to reorganise.
There’s no isolation in the body.
It’s all one big, slightly chaotic, beautifully adaptive system.
What’s next (Part 2)
In Part 2, we’ll dig into:
Why “bad posture” isn’t the villain it’s made out to be
How pain and posture actually relate (and sometimes don’t)
What you should actually do about it
Spoiler: it won’t involve sitting like a robot.
References
Bogduk, N. (2005) Clinical Anatomy of the Lumbar Spine and Sacrum. 4th edn. Elsevier Churchill Livingstone.
Proske, U. and Gandevia, S.C. (2012) ‘The proprioceptive senses: their roles in signaling body shape, body position and movement, and muscle force’, Physiological Reviews, 92(4), pp. 1651–1697.
Schache, A.G., Blanch, P.D., Rath, D.A., Wrigley, T.V. and Bennell, K.L. (2002) ‘Three-dimensional angular kinematics of the lumbar spine and pelvis during running’, Human Movement Science, 21(2), pp. 273–293.
Shumway-Cook, A. and Woollacott, M.H. (2017) Motor Control: Translating Research into Clinical Practice. 5th edn. Lippincott Williams & Wilkins.