Do Kids Have Flat Feet on Both Feet or Just One? – What Parents Need to Know

June 16, 2026 Shoes for Flat Feet Juan Valenzuela 0 - Comments

By Juan Valenzuela | Certified Children’s Shoe Fitter with 10+ Years of Experience | Last updated: June 2026

One of the most common questions I receive from parents is whether children typically have flat feet on both feet or just one. It’s a question that matters more than it might seem — because the answer affects how you approach footwear, whether orthotics are needed, and what risks to watch for. After ten years of fitting children’s shoes and working alongside pediatricians and physical therapists, I can give you a clear, practical answer.

Is It Normal for Children to Have Flat Feet?

Yes — flat feet are completely normal in babies and toddlers. All children are born with flat feet. The arch develops gradually during the first few years of life as the bones, ligaments, and muscles mature and strengthen.

^{An image of a child with flat feet and a moderate degree of pronation standing barefoot.}

Most children develop a visible arch by age four or five. If the arch has not developed by then, it’s unlikely to develop on its own — and this is the point where parents need to take proactive action. The first seven years of childhood are the most important window for intervention. During this period, the foot structures are still forming and respond well to the guidance of supportive shoes and orthotics. Waiting past this window makes meaningful improvement progressively harder to achieve.

Do Kids Have Flat Feet on Both Feet or Just One?

Most children with flat feet have both feet affected. In the majority of cases I see in fittings, both feet are flat — though the degree of flatness and pronation can differ significantly between the right and left foot.

That said, it’s entirely possible for a child to have flat feet on only one foot, or to have one foot significantly flatter than the other. This asymmetry can result from several factors:

Conditions like leg length discrepancy, which can cause one foot to bear more load and collapse further
Differences in bone structure between the two feet
Muscle imbalances — one side stronger or tighter than the other
An injury or developmental difference affecting one limb

How to Tell If Your Child Has One or Both Feet Flat

You don’t need a specialist appointment to make an initial assessment. Here are two simple checks:

Look from behind. Have your child stand barefoot on a hard floor and observe their ankles from directly behind. If the ankle bones dip inward — toward each other — the arch on that side is collapsing. Check each side independently. If both ankles dip, both feet are likely flat. If only one dips, you may be dealing with unilateral flat foot.

Check the footprint. Wet your child’s feet and have them step onto a piece of cardboard or dark paper. A foot with a normal arch leaves a partial footprint with a gap in the midfoot. A flat foot leaves a full, connected footprint with no gap. Compare left and right.

If you’d like a more precise assessment, you can send me two photos of your child’s feet — one of the right foot and one of the left — along with a short video of them walking, to customerservice@fittingchildrenshoes.com. I’ll review them and give you specific feedback on what I’m seeing and what I’d recommend.

Why It Matters If Only One Foot Is Flat

When both feet are flat to the same degree, the approach is straightforward — supportive shoes and, where needed, orthotics for both feet. When only one foot is flat — or when one is significantly flatter than the other — the situation requires more careful handling.

Leg length discrepancy. When one foot collapses significantly more than the other, it functionally shortens the leg on that side. The hip and pelvis compensate by tilting, creating a functional leg length difference even when the bones are the same length. This can lead to knee, hip, and lower back pain over time.

Posture asymmetry. If the body is bearing weight differently on each side for months or years, the spine and hips adapt to the asymmetry. These compensatory patterns become increasingly ingrained and harder to correct.

The orthotics trap. This is the most important practical point I give parents: do not add arch support to only one foot without carefully accounting for the height difference it creates. Adding an orthotic to a flat foot raises that side of the body. If you only do it on the flatter side, you’ve effectively made one leg functionally longer — which can cause or worsen the very posture problems you’re trying to prevent.

The correct approach when one foot is flatter than the other is to treat both feet — using orthotics of different heights if needed — or to consult with a physical therapist or pediatric podiatrist about the specific degree of asymmetry and the appropriate correction.

Can Flat Feet Be Fixed?

This is one of the most common questions I get — and one of the most important places to be honest with parents.

Flat feet cannot be permanently fixed. It is a structural and hereditary condition. No exercise program, orthotic, or shoe will give a flat-footed child a permanent arch. Anyone claiming otherwise is not giving you accurate information.

What can be achieved — and what I see regularly in my fitting work — is:

Significant reduction or complete elimination of foot and leg pain
Meaningful improvement in walking gait and overall posture
Prevention of the secondary conditions that untreated flat feet cause over time
Correction of the functional alignment problems (rolled ankles, knocked knees, out-toeing) that flat feet drive

The goal is not to fix the arch. The goal is to support the foot in a way that allows the child to move comfortably, develop properly, and avoid the chronic pain that inadequately supported flat feet cause.

Signs and Symptoms to Watch For

Flat feet in children are not always painful — particularly in younger children whose bodies haven’t yet accumulated enough cumulative stress to trigger symptoms. But the absence of pain does not mean the condition is harmless. Watch for:

Foot pain. Discomfort or aching in the heel, arch, or ankle — particularly after activity or at the end of the day.

Leg fatigue. Complaining of tired or heavy legs after walking shorter distances than peers. Children with flat feet work harder to maintain forward momentum with every step.

Unusual gait patterns. Overpronation (feet rolling inward), out-toeing (feet pointing outward), or frequent tripping can all be driven by flat feet.

Avoidance of physical activity. Children who stop wanting to participate in sports, running, or active play — particularly if they were previously active — sometimes do so because activity has become painful without them being able to articulate why.

Uneven shoe wear. Check the outsoles of your child’s shoes. Flat-footed children typically show heavy wear along the inner edge, particularly at the heel and forefoot.

If you’re seeing any of these signs, it’s worth acting rather than waiting — particularly during the developmental window before age seven.

What to Look for in a Shoe for Flat Feet

Two features matter most:

Straight last. The last is the form around which the shoe is built. A straight last runs in a nearly straight line from heel to toe, helping guide the foot toward a more neutral position during walking. Curved lasts — found in many fashion sneakers — encourage the inward rolling that flat feet are already prone to.

^{Always try to avoid shoes with excessively curved lasts.}

Firm heel counter and stable base. A firm heel counter holds the heel upright and reduces ankle rolling. A wide, dense outsole provides the stable platform that distributes weight evenly rather than concentrating it along the inner edge.

^{You want to look for shoes with ample cushioning to provide a comfortable and shock-absorbing base as this can help alleviate pressure on your kid’s feet and joints.}

For a full list of recommended shoes by age, width, and severity, see Best Shoes for Kids with Flat Feet.

Before and After: What Supportive Shoes Do

The visual difference between a child with flat feet standing barefoot and the same child in a supportive shoe is one of the most striking things I show parents — and it’s immediate.

^{An image of a toddler with flat feet standing barefoot versus wearing supportive shoes.}

^{An image of an older child with flat feet standing barefoot versus wearing supportive shoes.}

The improvement is not from orthotics in these images. It’s from correctly structured everyday sneakers with the right last, heel counter, and outsole.

Should My Child Also Wear Orthotics?

Start with supportive shoes and monitor for two to three months. Many children with mild to moderate flat feet see significant improvement with footwear alone.

If your child is still experiencing pain, if the flat feet are moderate to severe, or if a physician has recommended additional support, orthotics are the appropriate next step. They provide targeted arch correction that complements the shoe’s structural features. For a full overview, see Orthotic Inserts for Kids with Flat Feet.

Important reminder for unilateral cases: If only one foot is flat, do not add an orthotic to just that foot without carefully considering the functional height difference it creates. Consult with a physical therapist or podiatrist about the appropriate correction for each side.

Getting the Right Fit

A correctly chosen shoe in the wrong size provides no benefit. A shoe that’s too short compresses the toes and causes blisters; too long and the foot slides forward, reducing contact with the heel counter and losing the corrective effect.

Measure both feet and size for the larger one. Learn how to measure your child’s foot accurately at home here.