In This Article

• What Are Flat Feet?
• Flexible vs. Rigid Flat Feet
• What Causes Flat Feet in Adults?
• Signs Your Flat Feet Need Treatment
• How We Diagnose Flat Feet
• Treatment Options That Actually Work
• Best Exercises for Flat Feet
• Flat Feet in Children: When to Worry
• Frequently Asked Questions

What Are Flat Feet?

Flat feet — medically known as pes planus — is a condition where the medial longitudinal arch of the foot is significantly reduced or absent. When you stand, the entire sole of your foot makes contact with the ground instead of having the normal arch gap along the inner side of your foot.

Flat feet are extremely common, affecting approximately 20-30% of the general population. Most people are born with flat feet — the arch typically develops during childhood between ages 3 and 6. For some, the arch never fully develops; for others, it collapses later in life due to injury, aging, or progressive tendon dysfunction.

Having flat feet does not automatically mean you need treatment. Many people with flat arches live active, pain-free lives. Treatment becomes necessary when flat feet cause pain, functional limitations, or progressive deformity — and that is where proper podiatric evaluation becomes essential.

Flexible vs. Rigid Flat Feet: Why the Distinction Matters

The single most important distinction in evaluating flat feet is whether they are flexible or rigid. This determines your prognosis and treatment options.

Flexible flat feet are by far the more common type. With flexible flat feet, your arch appears when you sit down or stand on your toes, but collapses when you bear weight normally. The foot retains its full range of motion, and the joints are not fused or arthritic. This type responds well to conservative treatment including custom orthotics, physical therapy, and supportive footwear.

Rigid flat feet are less common but more concerning. With rigid flat feet, the arch is absent regardless of position — whether you are sitting, standing, or on your toes. This often indicates underlying structural issues such as tarsal coalition (abnormal bone fusion), advanced posterior tibial tendon dysfunction, or arthritis in the midfoot joints. Rigid flat feet are more likely to require advanced intervention including bracing or surgical reconstruction.

What Causes Flat Feet in Adults?

While some people simply never develop an arch during childhood, many adults develop flat feet later in life — a condition called adult-acquired flatfoot deformity (AAFD). The most common cause is posterior tibial tendon dysfunction (PTTD), where the tendon that supports the arch gradually weakens, stretches, and eventually fails.

Other common causes include obesity and excess body weight (which increases mechanical load on the arch), pregnancy (hormonal changes that loosen ligaments), aging and natural tendon degeneration, rheumatoid arthritis or other inflammatory joint conditions, diabetes-related Charcot foot, and traumatic injuries to the foot or ankle that damage arch-supporting structures. Risk factors that accelerate arch collapse include prolonged standing occupations, high-impact activities without proper footwear, and biomechanical abnormalities like tight calf muscles or excessive pronation.

Signs Your Flat Feet Need Treatment

Many people with flat feet are completely asymptomatic. However, there are clear signs that indicate your flat feet have progressed beyond a cosmetic concern and need professional evaluation:

• Pain along the inner ankle or arch — especially during or after walking or standing
• Shin splints — recurrent pain along the front of the lower leg
• Knee or hip pain — flat feet alter your entire lower extremity alignment
• Lower back pain — biomechanical chain reaction from foot to spine
• Shoes wearing unevenly — excessive wear on the inner edge
• Difficulty standing on your toes — may indicate posterior tibial tendon damage
• Visible arch collapse that has gotten worse over time
• Swelling along the inner ankle — a hallmark of PTTD

How We Diagnose Flat Feet

At Balance Foot & Ankle, Dr. Tom performs a comprehensive biomechanical evaluation that goes far beyond simply looking at your arch. The evaluation includes a weight-bearing examination assessing arch height, heel alignment, and forefoot position, the single heel raise test (can you rise onto your toes on one foot — failure suggests PTTD), gait analysis to evaluate how your flat feet affect your walking pattern, joint range of motion testing to determine flexibility vs rigidity, and muscle strength testing of the posterior tibial tendon and peroneal muscles.

Imaging studies include weight-bearing X-rays to measure arch angles and assess bone alignment, ultrasound to evaluate posterior tibial tendon integrity, and MRI when tendon tears or advanced joint changes are suspected. These objective measurements allow us to classify the severity of your flatfoot (stages I-IV) and create a precisely targeted treatment plan.

Treatment Options That Actually Work

Custom Orthotics: The Foundation of Flat Feet Treatment

Custom 3D orthotics are the single most effective non-surgical treatment for symptomatic flat feet. Unlike generic arch supports you buy at the drugstore, custom orthotics are precisely molded to your foot anatomy using advanced 3D scanning technology. They provide the exact amount of arch support your foot needs, control excessive pronation, and redistribute pressure away from overloaded structures.

For most patients with flexible flat feet, custom orthotics combined with proper footwear eliminate or dramatically reduce symptoms. The orthotics work by mechanically supporting the arch and controlling the rearfoot, which reduces strain on the posterior tibial tendon and prevents progressive arch collapse. Most patients notice significant improvement within 2-4 weeks of consistent wear.

Physical Therapy and Strengthening

Targeted physical therapy addresses the muscular weakness and tightness that contribute to arch collapse. The posterior tibial muscle, intrinsic foot muscles, and calf complex all play roles in maintaining dynamic arch support. A structured rehabilitation program strengthens these muscles and restores the active support system that complements the passive support provided by orthotics.

Advanced and Surgical Options

For progressive flatfoot deformity that has not responded to conservative care, surgical options include tendon repair or transfer (for PTTD), calcaneal osteotomy (heel bone realignment), medializing calcaneal osteotomy with tendon augmentation, and in severe cases, subtalar joint fusion or triple arthrodesis. EPAT shockwave therapy and MLS laser therapy can also help manage pain and promote healing in the associated tendon and ligament structures.

Best Exercises for Flat Feet

These exercises strengthen the muscles that support your arch and improve foot function. Perform them daily for best results:

• Towel scrunches — Place a towel on the floor and use your toes to scrunch it toward you. 3 sets of 15 repetitions. Strengthens intrinsic foot muscles.
• Heel raises — Stand with feet hip-width apart and slowly rise onto your toes. Hold 3 seconds, lower slowly. 3 sets of 15. Strengthens posterior tibial and calf muscles.
• Arch lifts (short foot exercise) — While standing, try to lift your arch without curling your toes. Hold 5 seconds. 3 sets of 10. Directly targets the arch-supporting muscles.
• Calf stretches — Wall stretch holding 30 seconds, 3 repetitions each leg. Tight calves contribute significantly to arch collapse.
• Single-leg balance — Stand on one foot for 30 seconds. Progress to standing on an unstable surface. Improves proprioception and dynamic foot stability.

Flat Feet in Children: When to Worry

Flat feet in children are extremely common and usually completely normal. Nearly all infants and toddlers have flat feet — the arch develops gradually between ages 3 and 6, and sometimes later. Most children with flat feet require no treatment whatsoever.

However, a pediatric podiatric evaluation is recommended if your child complains of foot, ankle, or leg pain during activity, avoids physical activity or sports due to foot discomfort, has one foot significantly flatter than the other, has rigid flat feet (arch absent even when not bearing weight), or has flat feet that are getting progressively worse after age 6. Early intervention with orthotics in symptomatic children can support normal arch development and prevent compensatory problems in the knees, hips, and back.

Frequently Asked Questions

Can flat feet be corrected in adults?

Flexible flat feet can be effectively managed and symptoms eliminated with custom orthotics, physical therapy, and proper footwear. While these treatments do not permanently change the bone structure, they provide the support needed for pain-free, active living. For severe or progressive deformity, surgical reconstruction can restore arch height and alignment.

Are flat feet genetic?

Yes, genetics play a significant role. If one or both parents have flat feet, you are more likely to have them as well. The genetic component affects bone structure, ligament laxity, and tendon strength — all factors that influence arch development and maintenance.

Can I run with flat feet?

Absolutely. Many successful runners have flat feet. The keys are wearing appropriate stability or motion control running shoes, using custom orthotics designed for your running gait, gradually building mileage to allow tissues to adapt, and incorporating the strengthening exercises described above into your routine.

Do over-the-counter arch supports work for flat feet?

OTC arch supports may provide mild relief for very mild cases, but they are generic and not designed for your specific foot anatomy. Custom orthotics provide significantly better outcomes because they are molded to your exact foot shape, control your specific biomechanical issues, and can be adjusted as your condition changes.

Sources

1. Arain A, Harrington MC, Rosenbaum AJ. Adult Acquired Flatfoot. StatPearls. Updated 2025.
2. Bowring B, Chockalingam N. Conservative treatment of tibialis posterior tendon dysfunction. Foot. 2010;20(1):18-26.
3. Deland JT. Adult-acquired flatfoot deformity. J Am Acad Orthop Surg. 2008;16(7):399-406.
4. Lee MS, et al. Diagnosis and treatment of adult flatfoot. J Foot Ankle Surg. 2005;44(2):78-113.

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Dr. Tom Biernacki, DPM

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Dr. Tom Biernacki, DPM is a double board-certified podiatrist and foot & ankle surgeon at Balance Foot & Ankle Specialists in Southeast Michigan. With over a decade of clinical experience, he specializes in heel pain, bunions, diabetic foot care, sports injuries, and minimally invasive surgery. Dr. Biernacki is a member of the APMA and ACFAS, and his patient education content on MichiganFootDoctors.com and YouTube has reached over one million views.