Can Flat Feet Cause Foot Pain?

Somebody's looked at your feet at some point — a shoe salesperson, a doctor, maybe just you noticing your footprint in the sand — and said the word "flat." Ever since, there's been a low hum of assumption that this explains whatever foot pain shows up. Standing hurts? Must be the flat feet. Arch feels tired after work? Flat feet, obviously.

Here's the more complicated, more useful truth: most people with flat feet have no pain at all. Research consistently describes flat feet as commonly painless, often just a normal variation in foot structure that never causes a problem.[^1] So if you have flat feet and you're also dealing with foot pain, the flat feet themselves might not automatically be the explanation — or they might be a genuine contributing factor. Telling the difference actually matters.

Flat feet can contribute to foot pain, but the relationship isn't automatic — the majority of people with flat feet experience no symptoms whatsoever. Pain becomes more likely when flat feet are accompanied by weakness in the muscles and tendons that support the arch, particularly the posterior tibial tendon, or when flat feet developed later in life (adult-acquired) rather than being present since childhood. The type and cause of your flat feet meaningfully changes both the likelihood of pain and the right treatment approach.

Let's get into why flat feet sometimes hurt and sometimes don't, and how to figure out which situation you're actually in.

Can Flat Feet Cause Foot Pain?:

Why "Flat Feet" Isn't Really One Single Thing

This is probably the most important distinction that gets glossed over constantly: there are different categories of flat feet, and they behave very differently.

Flexible flat feet are the most common type. The arch is low or absent when you're standing and bearing weight, but reappears when you lift your foot off the ground or sit down. This type is frequently present from childhood, is often at least partly hereditary, and — this is the key part — is very often completely painless throughout someone's entire life.[^2]

Rigid flat feet are less common and behave differently — the arch stays flattened regardless of whether weight is on the foot or not. This type is more often associated with pain, stiffness, and feet that tire easily.[^3]

Adult-acquired flatfoot is a distinct and more clinically significant category. Unlike the flat feet someone's had since childhood, this develops later in life, usually due to dysfunction of the posterior tibial tendon — the tendon primarily responsible for supporting your arch during standing and walking. When that tendon becomes overloaded, inflamed, or degenerates over time, the arch that was previously fine starts to collapse, and this specific version is much more strongly and directly associated with actual pain.[^4]

If your flat feet have been there your whole life and pain just recently showed up, that combination is worth paying attention to — it may point toward this adult-acquired pattern rather than your longstanding foot structure suddenly becoming a problem out of nowhere.

What Actually Determines Whether Flat Feet Cause Pain

Given that most flat feet are painless, what separates the ones that hurt from the ones that don't?

Muscle and tendon support matters more than arch height itself. Research has proposed that dysfunction in the muscles and tendons supporting the arch — not simply the flatness of the arch as a static structural fact — is what actually links flat feet to pain and injury in many cases.[^5] Two people can have visually identical flat feet, and one has pain while the other doesn't, largely based on how well the surrounding musculature is doing its job.

Whether it's flexible or rigid matters. As covered above, rigid flatfoot is more consistently linked to pain than the flexible variety.

Activity level and demands on the foot matter. Research has found that people who run or spend long periods on their feet are more likely to develop problems related to flat feet than people with lower activity demands, even with the same foot structure.[^3]

Whether it developed recently versus lifelong is a genuinely important distinguishing factor, since recently developed flattening in an adult often points toward tendon dysfunction requiring its own specific attention, rather than a lifelong structural variant that's simply always been part of how your feet are built.

Beyond Just the Foot: What Flat Feet Can Affect Further Up the Chain

Flat feet don't necessarily stay contained to the foot itself. Research has explored associations between flat foot severity and issues elsewhere in the body — including a documented association with low back pain, theorized to occur through altered lower limb alignment creating additional spinal stress that accumulates over time.[^6] Some research has also examined connections between flat feet and knee pain, through similar altered alignment mechanisms working their way up the kinetic chain.

This doesn't mean flat feet are destined to cause problems elsewhere. It means that when someone has both flat feet and pain in the knee, hip, or back with no other clear explanation, the foot structure is at least worth considering as part of the full picture.

How Assessment Sorts Out Whether Your Flat Feet Are Actually the Problem

Given how commonly flat feet exist without causing any trouble, assessment needs to determine whether your specific flat feet are actually contributing to your specific pain, rather than assuming a connection just because both are present.

We assess whether your flat feet are flexible or rigid, since that changes both prognosis and treatment approach. We test the strength of the muscles and tendons supporting your arch, particularly assessing the posterior tibial tendon specifically, since dysfunction there is one of the more common actual drivers of flat-foot-related pain. We look at when this started — lifelong versus a more recent adult-acquired pattern — since that timeline carries real diagnostic weight. And we assess whether pain elsewhere in the leg, knee, hip, or back might be connected to altered mechanics coming from the foot.

What Treatment Actually Looks Like

If assessment identifies muscle or tendon weakness contributing to symptomatic flat feet, treatment centers on strengthening the muscles that support the arch — particularly the posterior tibial tendon and surrounding musculature — since building that support often meaningfully reduces symptoms even without changing the underlying foot structure itself.

Supportive footwear and, in some cases, orthotic inserts help distribute load more evenly and reduce strain on overworked structures, particularly for people with higher activity demands who are on their feet a lot.

For adult-acquired flatfoot specifically, treatment addresses the underlying tendon dysfunction directly, and depending on severity, this sometimes requires closer coordination with a physician alongside physical therapy.

If pain elsewhere in the body appears connected to your foot mechanics, treatment addresses the full chain rather than focusing narrowly on the foot alone.

When It's Worth Getting This Looked At

Worth scheduling an evaluation if: you have flat feet and foot pain and aren't sure whether they're actually connected, your arch seems to have flattened more recently as an adult, you're experiencing knee, hip, or back pain alongside known flat feet, or supportive footwear alone hasn't resolved ongoing discomfort.

Common Questions About Flat Feet and Foot Pain

If I've had flat feet my whole life without pain, should I worry about it now?

Not necessarily — many people go their entire lives with flat feet and never develop symptoms. If pain is new, it's worth figuring out whether something has actually changed (like tendon function) rather than assuming your longstanding foot structure is suddenly the cause.

Are orthotics always necessary for flat feet?

No — orthotics help some people, particularly those with higher activity demands or specific tendon-related dysfunction, but they're not automatically required for everyone with flat feet, especially those without symptoms.

Can flat feet be "fixed" through exercise?

Structural, lifelong flexible flatfoot generally isn't something exercise permanently reshapes, but strengthening the supporting muscles and tendons often meaningfully reduces or eliminates associated pain regardless.

Is rigid flatfoot more serious than flexible flatfoot?

Rigid flatfoot is more consistently associated with pain and stiffness, and is worth a more thorough evaluation, though "more serious" depends on your specific symptoms and function.

Could my knee or back pain actually be coming from my feet?

It's possible — research has found associations between flat foot severity and both low back and knee pain through altered lower limb mechanics, so it's a reasonable thing to investigate if no other clear cause has been identified.

Do children with flat feet need treatment?

Often not — flat feet are extremely common in young children and frequently resolve naturally as the foot develops, with the vast majority no longer showing significant flattening by around age ten.

What's the difference between flat feet I've had forever and "adult-acquired" flat feet?

Lifelong flat feet are typically a structural variant present since childhood, often without symptoms. Adult-acquired flatfoot develops later, usually due to posterior tibial tendon dysfunction, and is more directly and consistently linked to pain.

Is surgery ever necessary for flat feet?

Rarely for typical flexible flatfoot. It's occasionally considered for more significant adult-acquired flatfoot or rigid flatfoot that hasn't responded to conservative treatment, but conservative care is almost always the appropriate starting point.

Can Flat Feet Cause Foot Pain?: Bottom Line

Flat feet and foot pain aren't automatically the same story — most people with flat feet have no pain whatsoever, and when pain is present, it's often driven by muscle or tendon dysfunction rather than the flatness of the arch itself. Whether your flat feet are flexible or rigid, lifelong or recently developed, all changes both the likelihood that they're actually contributing to your pain and what treatment should focus on.

Dealing with foot pain and unsure whether your flat feet are actually the cause?

Schedule a Physical Therapy Evaluation at Nashville Physical Therapy & Performance. You'll get completely 1:1 care with your therapist for the entire visit — no aides, no split attention. We'll assess your specific foot structure and function and determine what's actually driving your pain. Available at South Nashville, East Nashville, Goodlettsville, and The Nations/West Nashville. Call 615-428-9213 or book online at nashvillept.com.

References

[^1]: Sports Injury Clinic. Flat Feet (Pes Planus): Symptoms & Treatment. 2026.

[^2]: Comparison of Navicular Mobilization and Rigid Tape in Pes Planus. ClinicalTrials.gov. NCT05354180.

[^3]: Sports Injury Clinic. Flat Feet (Pes Planus): Symptoms & Treatment. 2026.

[^4]: Pinney SJ, Lin SS. Current concept review: acquired adult flatfoot deformity. Foot & Ankle International. 2006;27(1):66-75.

[^5]: Flatfeet: Biomechanical implications, assessment and management. Foot and Ankle Surgery. 2019.

[^6]: Association between Flat Foot Severity and Low Back Pain Recurrence among Pre-Clinical Medical Students: A Cross-Sectional Study. 2019.