Plantar Fasciitis: What It Is, Why It Happens, and How Orthotics Actually Help

A Stride Soles weekly discussion with Dr. Zac Cartun (CMO), Greg Gerla (CEO), and Dominik (Head of Design)

Quick Introductions

Greg Gerla:
Hello everybody, welcome to another edition of our Stride Soles weekly discussion. How about we all introduce ourselves? I'm Greg Gerla, co-founder and CEO of Stride Soles.

Zac (Dr. Zach Cartun):
I'm Zach Cartun, physician and Chief Medical Officer of Stride Soles.

Dominik Walter:
And I'm Dominik — head of design at Stride Soles.

Greg:
Awesome. Today we're going to do a deep dive into plantar fasciitis, which is actually our most common use case for people purchasing orthotics.

So let’s start simple: What is the plantar fascia, and what is plantar fasciitis?

What Is the Plantar Fascia? What Is Plantar Fasciitis?

Zac:
Alright — the plantar fascia is a band of tissue that goes from the heel bone (the calcaneus) through the arch and into the toes. It supports the muscles and ligaments of the foot.

Plantar fasciitis happens when the insertion of that structure into the heel gets damaged and inflamed. It can start as irritation but can extend into small tears.

Typically, people experience really severe heel pain in the morning, but it can also cause discomfort elsewhere depending on the person.

Greg:
Anything to add, Dominik?

Dominik:
No — that’s it. Very good.

How Do You Know If You Have Plantar Fasciitis?

Greg:
What are the symptoms you’re going to feel?

Zac:
The classic symptom is heel pain, especially with the first steps out of bed. It might calm down as you walk a little.

But then the sneaky part: it often comes back later in the day — sometimes even worse. Not everyone feels it in the heel only. Some people feel it in the arch or midfoot.

So honestly: any kind of persistent foot discomfort could be plantar fasciitis.

Dominik:
And in many cases you can trigger it manually. If you press with your thumb on the inner/medial part of the heel and it causes a sharp pain — like there’s a nail inside your heel — that’s a classic sign.

Why Is Plantar Fasciitis So Common Now?

Greg:
This question comes up a lot: why is it so prevalent? Is it sedentary lifestyle? Not stretching? Why does everyone seem to have it?

Dominik:
In my opinion it’s clear: we don’t move naturally anymore.

We wear shoes all the time — and many of them are too soft. The softness removes information from the ground, so we walk without muscle reaction. The softer the shoe, the more the foot collapses into misalignment, and that puts unhealthy tension on the plantar fascia.

Also: artificial flat floors.

Zac:
Totally. It also tends to worsen with age.

And for some people it happens idiopathically — meaning we can’t point to one specific cause — but usually it’s environmental: improper footwear, surfaces, movement patterns.

Dominik:
And also load matters. If there’s too much weight or load, it’s also a reason.

Greg (laughing):
We don’t use the word “fat” in America anymore.

Dominik:
Really? Man…

What Shoes Are Best for Plantar Fasciitis?

Greg:
Before orthotics — let’s talk shoes. Any recommendations for what to look for at a shoe store?

Dominik:
Stability is important. Very soft shoes are usually not good. You want torsional stability — meaning the shoe shouldn’t twist too easily.

Ideally: a wide toe box, so the big toe can spread inward to support the foot.

Greg:
What shoe type is that?

Dominik:
A running shoe brand — an American one: Altra.

Greg:
Interesting. We should make a video just on shoes.

Why Do Orthotics Help Plantar Fasciitis?

Greg:
Alright. Orthotics. Why are orthotics generally helpful for plantar fasciitis?

Dominik:
The main reason is weak foot muscle and lack of support. Orthotics help build muscle by innervating them — you get an active treatment.

It supports the foot in a way that unhealthy movement becomes less possible.

Zac:
I agree — but I want to add something important: not all insoles are created equally.

There’s design and choice involved: shape, rigidity, softness, where the arch support is, how it fits your foot. Those choices determine whether it actually treats plantar fasciitis — or just “feels soft.”

The 5 Design Elements That Matter Most (and Why)

Greg pulled up a list of Stride Soles plantar fasciitis design features — and Dominik walked through each one using a printed orthotic model.

1) The Groove Shape Over the Plantar Fascia

Greg:
I have “groove-shaped recess over the plantar fascia.” Explain what that is?

Dominik:
Zac — do you have another insole you can show? Like a competitor? For comparison?

Zac:
Yeah — here’s the Upstep.

Dominik:
Perfect. Compare them.

Upstep’s arch support is shaped more like a convex hump, which adds pressure into the plantar fascia area. That can increase tension.

Ours is shaped more like a ramp — a groove in an anatomical way. We leave space here so we’re not pressing directly into the plantar fascia.

So: we support the arch without poking the inflamed structure.

Greg:
So it’s not a harsh “hole” or recess?

Dominik:
Right — we don’t want sharp edges. If it’s misaligned during walking, it becomes painful again. The groove has to be smooth.

2) The Extended Heel Tail (Outside Heel Activation)

Greg:
Next: the extended heel tail that activates ankle stabilizing muscles.

Dominik:
This is a bit of a German translation — “heel tail” basically means the outside of the heel, here.

There’s a small bump that stimulates the peroneus muscles, which stabilize the ankle. Studies show increased functionality.

Greg:
Is that unique to plantar fasciitis orthotics?

Dominik:
We include it in all models somewhat, but it’s increased for plantar fasciitis. More activation.

But it has to be positioned carefully — too high and it becomes torture.

3) The Toe Bench (A Gentle Stretch at Push-Off)

Greg:
Toe bench — elevates toes to gently reduce tension?

Dominik:
This might sound counterintuitive because earlier we said we don’t want stretch.

But here’s the difference: during early stance we reduce tension — rearfoot support + heel wedge.

During toe-off, a slight toe elevation (2–5mm) gives a gentle stretch that mimics a home therapy: toes on a step, lowering the heel.

Zac:
And this is a big comparison point: Upstep’s plantar fasciitis orthotic doesn’t have toe modifications — it’s basically foam.

Even Dr. Scholl’s doesn’t have it either.

That means it’s missing a whole corrective benefit during gait.

4) Semi-Rigid Arch Support (The Goldilocks Zone)

Greg:
Semi-rigid arch support — why semi-rigid?

Dominik:
Rigid is not good. The foot needs flexibility. During load, muscles swell, you need space.

But we don’t want flimsy foam either.

We solved this with a closed outline: supportive structure around the edges, but flexible enough inside that the foot can swell and move without losing the shape entirely.

We provide support from the sides — not just pushing up from the bottom.

Zac:
It’s a Goldilocks zone: too rigid and the foot can’t expand; too soft and it does nothing.

And our 3D printing strategy is what allows that.

5) Increased Heel Height (Reduced Mid-Stance Tension)

Greg:
Lastly — increased heel height. Why?

Dominik:
By elevating the heel slightly, you take tension off the plantar fascia during mid-stance.

Think of high heels: after years the heel struggles to drop fully because tissues adapt. We don’t want that — we only want a small reduction to help healing.

Also: calf tension connects into plantar fascia.

“Symptom Relief” vs “Cause Treatment” (The Big Difference)

Greg:
These five features seem to make Stride Soles unique. How did we even come to this final design?

Dominik:
We start by asking: why does this happen?

Other manufacturers treat the symptom — make it soft, it feels good.

We treat the cause. We tested thousands of insoles, followed up in clinics, brought patients back after 10 weeks, measured and adjusted.

And we learned: humans aren’t machines.

That was hard for me as an engineer. It’s not always “if, then.” Sometimes people react counterintuitively.

So we learned through trial and error — thousands and thousands of orthotics.

What About Over-the-Counter Insoles?

Zac:
This part amused me.

I tried Dr. Scholl’s plantar fasciitis orthotics — I was disappointed. It has basically no real arch support. You can flatten it with your fingers, so imagine body weight.

The “plastic support” inside is super thin.

Weirdly, I was more pleasantly surprised by the CVS store brand — slightly more rigid support.

People ask us all the time: “Should I try OTC first?” We’re open to that.

But what happens is: people try one, doesn’t work, try another, doesn’t work… and lose months in pain.

They could have been treating it properly with something designed for their foot.

Dominik:
And you should never save money with your health. In Germany we say: buy cheap, buy twice.

Zac:
It’s not worth being in pain.

Final Thoughts

Greg:
That’s all I have for today. Thanks for joining us.

Zac:
Awesome. See you next week.

Dominik:
See ya.