How Flat Feet (Pes Planus) Can Lead to Plantar Fasciitis: What You Need to Know

Heel Pain in the Morning? It Might Start With Your Feet.

I see it all the time—patients come in complaining of sharp heel pain, especially when they take their first few steps out of bed.

It gets a little better as the day goes on, but by evening—or after standing too long—the pain is back.

Sound familiar?

If so, flat feet could be the real reason behind your discomfort—and that pain you're feeling? It’s often the early stages of plantar fasciitis.

At Walsh Chiropractic and Physical Therapy of Hagerstown, I always stress how important it is to understand your foot structure—because your feet are the foundation for everything above them.

What Are Flat Feet (Pes Planus)?

A Simple Definition

Flat feet, also called pes planus, happen when the arches of your feet collapse or fail to develop properly.

Some people have flexible flat feet (the arch flattens only when standing), while others have rigid flat feet (the arch remains flattened even when sitting).

Either way, without that natural arch support, your body has to compensate—and that’s where the problems begin.

Common Causes of Flat Feet

In my experience, flat feet often develop because of:

• Genetics (born with low arches)

• Injury or trauma to the foot or ankle

• Wearing improper footwear (like flip-flops or unsupportive shoes)

• Weakness or underdevelopment of the foot muscles during childhood

What Is Plantar Fasciitis?

Quick Overview

Plantar fasciitis is inflammation of the plantar fascia—the thick band of tissue running along the bottom of your foot from your heel to your toes.

When that tissue gets over-stretched or micro-torn, you feel:

• Sharp, stabbing heel pain

• Stiffness, especially first thing in the morning

• Pain after long periods of standing or walking

Risk Factors for Plantar Fasciitis

Some of the biggest risk factors I see in patients include:

• Spending long hours on your feet

• Running, especially without proper form

• Wearing worn-out shoes

• Having poor foot mechanics—like flat feet

How Flat Feet Contribute to Plantar Fasciitis

Altered Weight Distribution

When your arches collapse, your body weight shifts—putting excessive pressure on the heel and midfoot instead of distributing it evenly.

Over time, that pressure irritates the plantar fascia.

Increased Stress on the Plantar Fascia

Without a healthy arch, the plantar fascia gets stretched and strained with every step you take.

That repeated micro-trauma leads to inflammation, pain, and eventually, full-blown plantar fasciitis.

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View Full Video Transcript Here

Okay, now what we're going to talk about is pes planus.

What is pes planus? It sounds really bad—flat foot. It is really bad, and I'll tell you why.

I like to put physics into everything because it explains everything, right? So, everybody, when they talk about the arch of the foot, they think of that medial arch right here, right? That's not the only arch you have. You actually have three arches in the foot: you have the medial one, you have a lateral one, and you have one that bends the toes like this—kind of like the hand here, right? In the wrist, you also have an arch that does this as an exaggeration. So all three arches.

As we saw in the spine—what do curves in structure help do? They help dissipate forces, right?

Give you the example—no curve, you pound it, you can feel it. Put a little curve in there and you hit—and you feel how forces are dissipated. That's what these things do, right?

And this—this is actually... I could go on for about an hour and a half at least with this, but I won't.

What's going to happen is: in a flat foot, you're not dissipating the forces naturally, okay? So what happens is a couple things.

Number one: your angle of the foot changes—you start to pronate.

Now, like I said, we like straight things in long bones—you gotta be straight. So as you come out here, actually your Achilles tendon is going to curve because now your leg is going to be curved.

This is the medial side, this is the inside, this is the outside of the foot. You're standing behind them—this is the right foot—and then it's going to be like this.

Now your knee—your femur—it isn't going to keep going like this, it's going to go like this to bring you back to the hip, right? Because you should be hip-knee-ankle aligned. But if this is going this way, this has got to go this way.

Now the concave side of that knee is going to see more force. So eventually, what's going to happen is: if you're very athletic, it's going to start to get painful in the meniscus, in the medial side of the knee, and the medial plateau.

It's going to work its way up.

Whenever you already have the physics wrong with the dissipation of forces, now you're looking at the foot, the ankle, the knee, the hip, the SI joint, the low back—none of those are going to be right because the forces are going to be dissipated all wrong through those.

That's another topic too—I could talk on forever.

Now, this is a side view of a flat foot. Okay, so right now it's not dissipating any forces. Actually, it's creating a stretch tension on your plantar fascia—plantar fasciitis, right?

So that plantar fascia is something that goes from the calcaneus to the forefoot, and it helps hold that curve. When you don't have a curve, then it's being stretched—so you're probably having a lot of discomfort in the plantar fascia.

Eventually, the angle of the foot to the ankle—right here—you're going to see more force than here. That'll degenerate.

As you go up to the knee, it's going to come back—so the medial side of the knee is going to degenerate quicker than the lateral side.

It's just going to be a chain reaction of bad things happening starting in the foot.

You'll see sometimes flat feet are congenital—you were born with it.

There can also be athletic issues—running wrong, right?

When you walk, it's heel-to-toe, right?

When you run, it's toe-box—you’re supposed to land right here.

Why?

Let's just take a look at that.

As you plant your foot—heel first—what muscle is contracted mainly? Tibialis anterior. And that's going to take the brunt of the force.

You're not going through the arches of the foot to help dissipate it, so it's going straight up. Okay?

So it's a smaller muscle. It's going straight up, usually to the hip, IT band, SI joint, and low back.

Now, if you move and do what's called a ball-of-the-foot strike—what's happening now? What muscle is contracted? Your calves.

That's actually two muscles: gastrocnemius and soleus. Those are bigger muscles than tibialis anterior. They're made to take that force.

So now you're striking the ball of the foot—just this area. The heel's not on the ground yet.

And what happens is—that force goes through the arches. Arches do what? They dissipate forces.

So now you're lessening the forces before they're even sent up.

You've got a bigger muscle to go ahead and absorb those big forces, right?

So right there, the chain of force is a lot better for you.

That tells you—the structure right there tells you how you should be running.

Why run and not walk?

Because of the amount of forces and the timing of how long your foot is on the ground.

The faster you go—the more you run—you've got to change your planting of the foot because more forces are dissipating.

When you walk, it's one force.

When you run, you're multiplying that force.

Okay, so the reason why this is bad is a number of reasons.

It changes the whole physics of the foot, which now changes the physics of the ankle, the knee, the hip, the SI joint, the low back—and it's going to be a chain.

Eventually, long enough, it's going to affect all of those.

So what can you do?

Very good question.

Depending upon how bad it is, maybe a surgical intervention is needed.

First line is to get an orthotic that will support that arch—that will actually push this up and force it.

Typically what I see is: those are uncomfortable at first for somebody with a bad case and had it—you know—the longer that they've had it, their foot is used to it.

Also, these bones here too are starting to get arthritic because that's not the natural transmission of those forces, right?

So depending upon how long they've had it before they get an orthotic—that’s how much damage has already started in the foot, let alone the ankle, the knee, the hip, the SI side, the back.

Really, to be honest with you—a flat foot is a serious matter.

Because in time, it will affect the low back.

You're going to get chronic low back pain.

The longer that you hesitate to do something about that flat foot—get an orthotic, go get diagnosed and see what's going on—the worse the condition is going to get, and then the more involved the treatment's going to be.

Flat feet is not an easy matter.

It really won’t be.

In the long term, you're going to be miserable, basically.

And if you're an athlete, you want that taken care of quicker—sooner rather than later.

Okay, so that is pes planus, which is flat foot—kind of rolled up.

I could talk for hours about that.

Misalignment Further Up the Chain

Flat feet don’t just stop at the foot:

• They throw off your ankle alignment

• Cause the knees to rotate inward (valgus)

• Shift the hips and pelvis

• Lead to lower back strain

That’s why at Walsh Chiropractic and Physical Therapy of Hagerstown, we don’t just treat the foot—we address the entire kinetic chain.

Symptoms to Watch For

Signs of Plantar Fasciitis

• Heel pain (especially first thing in the morning)

• Pain that improves with movement, but worsens after prolonged standing

• Stiffness after sitting for long periods

Signs of Flat Feet Problems

• Your foot visibly flattens when you stand

• You notice overpronation—your foot rolls inward

• Frequent ankle sprains or foot fatigue

• Early aching in your knees, hips, or low back after walking

How I Help Patients Treat Flat Feet and Plantar Fasciitis

Foot and Ankle Adjustments

I often perform gentle foot and ankle adjustments to:

• Improve joint mobility

• Realign the bones of the foot

• Restore better weight distribution

Soft Tissue Therapy

We use myofascial release techniques to:

• Loosen tight calf muscles

• Release adhesions in the plantar fascia

• Ease tension in the Achilles tendon

Custom Orthotics and Footwear Guidance

In many cases, I recommend:

• Custom orthotic inserts

• Shoes with proper arch support and cushioning

Supporting the arch is crucial for force dissipation and long-term foot health.

Strengthening and Mobility Exercises

I teach patients exercises like:

• Towel scrunches to strengthen foot muscles

• Arch lifts to rebuild proper support

• Calf and hip strengthening to stabilize movement patterns

Proper movement = less stress on your feet and joints.

Prevention Tips for Flat Feet and Plantar Fasciitis

Strengthen Your Feet Regularly

Don’t wait until you’re in pain.

Simple daily exercises can maintain strong, supportive arches.

Choose the Right Footwear

I always say:

Your shoes are your foundation.

Make sure your footwear provides:

• Arch support

• Proper cushioning

• A stable heel counter

Stretch and Mobilize Key Muscles

Focus on stretching:

• Calves

• Achilles tendons

• Plantar fascia (gently rolling or manual stretching)

Consistent flexibility work keeps pressure off the plantar fascia.

When to See a Chiropractor About Flat Feet or Heel Pain

If you notice:

• Persistent heel pain

• Foot fatigue or collapse when walking

• Pain traveling up to your knees, hips, or back

…it’s time to get assessed.

The earlier we intervene, the easier it is to correct issues—and prevent more complex joint problems later on.

At my clinic in Hagerstown, I combine gentle adjustments, soft tissue therapy, orthotic guidance, and rehab to get you moving pain-free again.

Frequently Asked Questions About Flat Feet and Plantar Fasciitis

Can flat feet be corrected without surgery?

In many cases, yes—through custom orthotics, strengthening, and supportive care.

Is plantar fasciitis permanent?

Not if treated early. Conservative care often relieves symptoms within a few months.

Can flat feet cause knee and back pain?

Absolutely. Poor foot mechanics change how forces travel up your body, affecting everything from your ankles to your low back.

Are custom orthotics worth it?

In my experience, quality orthotics can be life-changing for chronic foot and joint issues.

Don’t Let Flat Feet Lead to Chronic Pain

Flat feet are common—but if left unaddressed, they can cause a chain reaction of problems up the entire body.

The good news?

With the right support, adjustments, and strengthening strategies, you can protect your feet, eliminate plantar fasciitis, and walk pain-free.

Schedule your foot and gait assessment today.

I’d love to help you move better, feel stronger, and stay active for life.