Not All Flat Feet Are a Problem

Flat feet (pes planus) are common—approximately 20–30% of adults have flatfoot deformity to some degree. The important distinction is between asymptomatic flat feet (present but causing no pain or functional problems) and symptomatic flat feet (causing pain, fatigue, activity limitation, or secondary problems). Asymptomatic flat feet require no treatment. Treatment is indicated only when flat feet are causing problems—not simply because they exist.

The arch of the foot develops during childhood and is typically formed by age 6–8. Children under 6 normally have flat feet due to fat pads obscuring the arch and ligamentous laxity. Adults who lose their arch after it was once normal (adult-acquired flatfoot) have a different condition than those who never developed one—and the causes and treatment differ accordingly.

Conditions Caused or Aggravated by Flat Feet

Flat feet alter the biomechanics of the entire lower extremity. Overpronation (inward rolling of the foot with arch collapse) during gait changes the alignment of the ankle, knee, and hip, causing a range of secondary problems. Understanding these connections helps patients appreciate why a podiatrist evaluating their knee pain or shin splints is examining their feet.

Conditions commonly associated with flat feet include plantar fasciitis (excessive tensile load on the plantar fascia), posterior tibial tendon dysfunction (PTTD), bunion formation and progression, shin splints (medial tibial stress syndrome), patellofemoral pain syndrome (runner’s knee), posterior knee pain, and lower back pain. For patients with these conditions, addressing the underlying flat foot deformity is part of effective treatment—not just symptom management.

Posterior Tibial Tendon Dysfunction (PTTD): The Adult Flatfoot Epidemic

PTTD—degeneration and dysfunction of the posterior tibial tendon—is the most common cause of adult-acquired flatfoot. The posterior tibial tendon is the primary dynamic supporter of the medial arch. When it degenerates and eventually tears, the arch collapses progressively. PTTD affects women over 40 disproportionately and is strongly associated with obesity, hypertension, and diabetes.

The classic presentation is a unilateral progressive flatfoot in a middle-aged woman with medial ankle pain and the inability to perform a single-leg heel raise (rising onto the toes of one foot). The “too many toes” sign—where more toes are visible on the outside when viewing the foot from behind—reflects the external rotation and abduction deformity of the progressive collapse.

PTTD is staged (I–IV) based on severity, and treatment is stage-dependent. Early PTTD (Stage I–II) can often be managed non-surgically. Advanced PTTD (Stage III–IV) with rigid deformity typically requires surgical reconstruction.

Non-Surgical Treatment for Symptomatic Flat Feet

Custom Orthotics

Custom orthotics are the cornerstone of conservative flatfoot treatment. A functional orthotic controls excessive pronation by providing medial arch support, a medial heel post (wedge) to correct rearfoot valgus, and forefoot correction for any forefoot supinatus deformity. The orthotic effectively replaces the arch support that the foot’s intrinsic and extrinsic structures are failing to provide.

For PTTD, a stiffer, more controlling orthotic or an Arizona brace (ankle-foot orthosis) is often required to prevent progressive tendon load. Custom orthotics for flatfoot should be fabricated from a corrected, non-weight-bearing mold of the foot—not simply a flat impression—to capture the foot in a corrected position.

Strengthening Exercises

The posterior tibial muscle and intrinsic foot muscles can be strengthened to provide better dynamic arch support. For early PTTD, a progressive exercise program involving posterior tibial strengthening (resisted inversion exercises with a resistance band), single-leg heel raises, and short foot exercises can prevent or slow progression. Exercise is most effective in Stage I PTTD before significant tendon degeneration. It’s less effective alone in more advanced disease but is an important adjunct to orthotic treatment at all stages.

Bracing

For patients with Stage II PTTD who haven’t responded adequately to custom orthotics, an Arizona brace (a custom leather ankle-foot orthosis that controls subtalar motion while allowing ankle flexion) provides more comprehensive support. Arizona bracing is an effective non-surgical option that allows continued daily activity for many patients who would otherwise require surgical reconstruction.

Surgical Options for Flatfoot

Surgery is considered when conservative treatment fails to provide adequate function or pain relief, or when deformity is advanced (Stage III–IV PTTD). Flatfoot surgical reconstruction is complex—typically combining procedures rather than a single operation. Common components include tendon reconstruction (FDL tendon transfer to replace/augment the failed posterior tibial tendon), calcaneal osteotomy (medializing the heel bone to restore alignment), medial column stabilization (Cotton osteotomy or first tarsometatarsal fusion), and Achilles/gastrocnemius lengthening for equinus contracture.

Recovery from flatfoot reconstruction is prolonged—typically 10–16 weeks non-weight-bearing followed by gradual progression over 6–12 months. Results are generally good for appropriately selected patients in experienced hands. The decision to proceed with surgery should be made with realistic expectations about recovery time and rehabilitation requirements.

Frequently Asked Questions

Medical References & Sources

• American Orthopaedic Foot & Ankle Society — Adult Acquired Flatfoot
• American Podiatric Medical Association — Flat Feet
• PubMed Research — PTTD Flatfoot Treatment

Dr. Tom Biernacki, DPM is a board-certified podiatric surgeon at Balance Foot & Ankle in Howell and Bloomfield Hills, Michigan. He treats symptomatic flat feet and PTTD with custom orthotics, bracing, and surgical reconstruction when indicated.

Dr. Tom Biernacki, DPM

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.