Podiatrist · Specialist in Biomechanics · Founder of VOLKAN
"Every time a shoe stops moving, someone has to do it in its place."
"I want a shoe that doesn't bend"
I remember a patient who had suffered persistent discomfort in the big toe.
He had read online that a very rigid sole could help him.
He arrived convinced.
—I need a shoe that doesn't flex.
I replied that probably, for a time, that could be a good strategy.
But then I added something that surprised him.
—The important thing is not that the shoe doesn't bend. The important thing is to know who will make that movement while it doesn't.
He looked at me in silence.
He had never considered that question.
And yet, that is one of the most interesting issues in the biomechanics of footwear.
Walking is continuously bending
Every step forces the foot to change shape.
The arch adapts.
The joints move.
The toes accompany the push.
The ankle constantly modifies its position.
Nothing remains completely rigid.
Walking is a succession of perfectly coordinated small deformations.
That ability to change shape allows for load distribution, energy absorption, and preparation for the next movement.
Mobility is not a detail of the step.
It is one of its conditions.
When the sole changes, the distribution of work changes
Imagine that you try to bend a steel ruler.
Then try with a plastic one.
The force needed is not the same.
With soles, something similar happens.
A very flexible sole more easily follows the movements of the foot.
A more rigid sole offers resistance to some of those movements.
That does not mean one is better than the other.
It means that the distribution of work changes.
Some structures participate more.
Others participate less.
And the organism reorganizes its strategy to keep moving forward.
Delegating is not always a problem
There is a tendency to think that any external help is negative.
I do not agree.
There are times when reducing the movement of a joint can be extraordinarily useful.
After a injury.
In certain degenerative processes.
When a tissue needs to temporarily reduce its load.
In those circumstances, a rigid sole can act as an excellent ally.
The problem arises when we forget to ask ourselves if that strategy is still necessary months or years later.
Because helping for a time is not the same as permanently replacing a function.
The foot learns by doing
In previous chapters we talked about motor learning.
The body improves when it participates.
Not when it observes.
The foot also learns.
Learns to manage loads.
To stabilize.
To propel itself.
To adapt to different surfaces.
To develop those capabilities it needs opportunities.
It does not mean that it must always face the maximum challenge.
It means that it needs to participate in the movement.
Every time a structure stops intervening for a long time, the organism loses part of the accumulated experience.
And the body never retains indefinitely what it stops using.
What does this have to do with barefoot?
A lot.
One of the most representative characteristics of minimalist footwear is precisely its high flexibility.
Not because a flexible sole is a virtue in itself.
But because it allows the foot to participate more directly in the movements for which it is designed.
That does not automatically make barefoot the best option for all people.
There are situations where greater rigidity is more appropriate.
The important thing is to understand what function we want to facilitate and which we are deciding to limit.
The question is not whether a sole should bend a lot or a little.
The question is what that organism needs at that moment in its adaptation process.
What I see every day in consultation
There are patients who feel a great improvement when we temporarily reduce the work of a joint through a more rigid shoe.
And others who discover a new sense of freedom when the foot starts to move more naturally thanks to a more flexible sole.
What’s truly interesting is not the shoe.
It’s observing how the behavior of the organism changes.
Because we never treat a sole.
We treat the way a person uses their body to interact with the ground.
What can you do starting today
Take two different pairs of shoes.
Try to bend them with your hands.
Observe how much they flex and where they do.
Then walk for a few minutes with each one.
Don’t just think about which one feels more comfortable.
Ask yourself something different.
Which one do I feel works my foot more?
There is no universal answer.
But learning to ask that question already changes the way we understand footwear.
🔬 In a sentence
The flexibility of a sole does not determine whether a shoe is better or worse. It determines how much of the movement will be done by the foot itself and how much will be taken on by the shoe.
The most important idea
Every step is the result of a continuous distribution of functions between the organism and the environment.
Footwear is part of that distribution.
A flexible sole allows the foot to participate more actively in certain movements.
A rigid sole can temporarily reduce the work of some structures when there is a reason to do so.
Neither option is correct by definition.
The important thing is to understand what function we are facilitating, which we are limiting, and whether that decision responds to a real need or simply to a habit.
Biomechanics does not consist of always choosing the same type of shoe.
It consists of understanding what tool the body needs to continue developing its ability to adapt.
A question to reflect on
Think about the footwear you use most frequently.
If your sole did a little less work… would your foot be ready to take on that part of the movement?
In the next article…
We have already covered the main characteristics of footwear: cushioning, stability, drop, fit, and flexibility.
The time has come to bring all those pieces together in a question that generates passionate opinions.
What is barefoot footwear really?
Is it a trend?
A philosophy?
A therapeutic tool?
A way to train?
A type of shoe?
In the next chapter, we will set aside myths and labels to answer a simple but fundamental question from biomechanics:
What does it really mean for a shoe to be barefoot?