— “Alignment” Is a Description, Not a Cause —

Today I want to talk about posture—
more precisely, about asymmetry.

In daily practice I often hear the same concerns:

  • “My spine is tilted.”

  • “One leg is longer than the other.”

  • “My pelvis is out of place.”

  • “One shoulder is higher.”

Many people have carried these thoughts for years,
believing that asymmetry itself is the reason for their pain.

A Perfectly Straight Spine Does Not Exist

I review spinal X-rays almost every day.
I have never seen a perfectly straight spine.

Not in professional ballet dancers.
Not in Olympic athletes.
Not even in myself—despite growing up in a family that has practiced Seitai for generations.

Human bodies are not built like rulers.

Nature Is Not Symmetrical

Look outside the clinic:

  • Trees do not grow perfectly straight.

  • Animals are not mirror images.

  • Humans are right-handed or left-handed.

Daily life always creates bias.
Asymmetry is normal biology, not a defect.

Athletes Are the Best Example

Fencing athletes show this clearly:

  • The lunge leg is visibly larger.

  • The weapon arm is stronger.

  • Hip mobility differs side to side.

Baseball players are the same—
throwing shoulders move differently from the other side.

In sports medicine this is not considered abnormal.
It is an expected adaptation to how the body is used.

The Real Issue Is Not Asymmetry

Asymmetry is a phenomenon, not a diagnosis.

What matters is:

  • knowing your baseline

  • noticing whether it is changing

  • understanding whether function is declining

Living under gravity, it is true that excessive leaning or imbalance can increase stress on tissues.
Research also shows that large and rapidly increasing asymmetries may raise injury risk.

But chasing perfect symmetry is unrealistic—
and often unnecessary.

The Problem Is Progressive Deviation

Asymmetry becomes meaningful only when it keeps getting worse:

  • posture drifts further over time

  • shoe wear suddenly changes

  • balance becomes harder than before

These are signs that functional movement capacity is declining.

On the other hand:

  • balance feels easier

  • asymmetry stops worsening

  • movement becomes smoother

These are positive signals.

We Do Not “Return” to Symmetry

The goal is not to make both sides identical.

In most adults that will never happen—
and forcing it often creates frustration.

I emphasize this because the word “alignment” has been heavily used for marketing:

  • “Your pelvis is out, that’s why you hurt.”

  • “Your shoulder height must be fixed.”

Thirty or forty years ago these explanations were common.
Even my family clinic, Nakano Seitai, once spoke this way.
Medicine evolves, and honest clinicians must evolve with it.

What Truly Matters

Not whether the body looks symmetrical—
but whether it functions safely and consistently.

The priority is:

  • knowing your personal baseline

  • observing deviations without clear cause

  • guiding the body back toward usable movement

Asymmetry is information, not an enemy.

And most importantly:

The goal is to raise functional movement capacity,
so you can continue to move on your own—
not to erase every visible difference between left and right.