Flat Feet: Symptoms, Causes & Treatment Options

What Are Flat Feet?

Flat feet (pes planus) is a condition where the arch of the foot is lower than normal or completely absent, causing the entire sole of the foot to contact the ground when standing. This structural variation affects 20-30% of the population, with most people experiencing no symptoms or functional limitations.

The foot's arch is a remarkable engineering structure that serves multiple critical functions. It acts as a shock absorber during walking and running, distributes body weight evenly across the foot, provides leverage for forward movement, and helps maintain balance. The arch is supported by a complex network of bones, ligaments, tendons, and muscles that work together to maintain its shape under the stress of daily activities.

When someone has flat feet, this arch support system is compromised. The medial longitudinal arch—the main arch running along the inside of the foot from heel to big toe—collapses partially or completely. This can occur in one foot (unilateral) or both feet (bilateral), and the severity can range from a mild flattening barely noticeable to the eye to a complete collapse where the arch touches the ground entirely.

It's important to understand that flat feet can be either flexible or rigid. Flexible flat feet, which represent the vast majority of cases, show an arch when the foot is not bearing weight (such as when sitting) but flatten when standing. Rigid flat feet maintain a flattened appearance regardless of whether weight is being placed on them, and these cases are more likely to cause symptoms and require treatment.

The Two Types of Flat Feet

Medical professionals distinguish between two main categories of flat feet based on when they develop:

Congenital flat feet (present from birth): Many children are born with flat feet, and this is considered a normal part of development. The arch typically develops gradually during childhood, usually becoming apparent by age 6. Some individuals, however, never develop a prominent arch, and their feet remain flat throughout life. In most of these cases, the flat feet cause no problems and require no treatment.

Acquired flat feet (develops later in life): Also known as adult-acquired flatfoot deformity (AAFD), this condition develops in adulthood, typically affecting people over 40. It occurs when the structures supporting the arch—particularly the posterior tibial tendon—weaken, stretch, or tear over time. This form of flat feet is more likely to cause symptoms and progress without treatment.

What Are the Symptoms of Flat Feet?

Common symptoms of symptomatic flat feet include pain along the inner side of the foot and ankle, pain under the arch or heel, swelling along the inside of the ankle, visible heel tilting outward when standing, difficulty standing on tiptoes, and tired, aching feet after prolonged standing or walking.

While many people with flat feet never experience any symptoms, those who do typically notice a gradual onset of discomfort that may worsen over time. The symptoms often develop slowly over months or years, making it easy to dismiss them as normal fatigue or minor aches. Understanding these symptoms is crucial for recognizing when flat feet might need attention.

The most characteristic symptom of problematic flat feet is pain along the inside of the foot and ankle. This pain originates from the posterior tibial tendon, which runs along the inner ankle and supports the arch. When this tendon is overworked or damaged, it becomes inflamed and painful. The pain may be sharp during activity and become a dull ache at rest.

Another common complaint is pain under the arch or heel. This occurs because the collapsed arch changes how weight is distributed across the foot, placing excessive stress on structures that weren't designed to bear such loads. Some people describe a burning sensation in the arch, while others feel a deep ache in the heel that's particularly noticeable first thing in the morning.

Visible Signs of Flat Feet

Beyond pain, there are several visible signs that may indicate flat feet are becoming problematic:

• The entire sole touches the ground: When standing, there is no visible gap between the inner foot and the floor
• Heel tilts outward: Looking from behind, the heel bone (calcaneus) angles away from the midline of the body
• "Too many toes" sign: When viewed from behind, more toes are visible on the outer side of the foot than normal
• Shoes wear unevenly: The inner edge of shoes, particularly the heel, shows excessive wear
• Swelling along the inner ankle: Visible puffiness along the course of the posterior tibial tendon

Functional Limitations

Symptomatic flat feet can affect daily activities in several ways. Many people notice they have difficulty standing on tiptoes, especially when trying to do a single-leg heel raise. This is because the posterior tibial tendon, which powers this movement, is weakened or damaged. Some individuals find they cannot walk or stand for extended periods without significant discomfort, limiting their ability to work, exercise, or enjoy leisure activities.

The condition can also affect gait patterns, leading to an altered walking style that may cause secondary problems in the knees, hips, or lower back. Some people develop a tendency to walk with their feet pointing outward (external rotation) as a compensation mechanism, which can lead to additional strain on other joints.

When Should You See a Doctor for Flat Feet?

You should see a doctor if you experience persistent pain on the inner side of your foot or ankle, pain that worsens with activity, visible changes in foot shape, difficulty walking or standing for long periods, swelling along the inside of the ankle, or if one foot becomes noticeably flatter than the other.

Not everyone with flat feet needs medical attention. However, certain signs and symptoms warrant professional evaluation. The key is distinguishing between flat feet that are simply a structural variation and those that are causing problems or may worsen without intervention.

Pain is the most important indicator that flat feet may need treatment. While occasional mild discomfort after a long day on your feet is normal, persistent pain—especially pain that occurs regularly during normal activities or prevents you from doing things you enjoy—should be evaluated. Pain that worsens over time rather than staying stable is particularly concerning.

Progressive changes in foot shape also warrant attention. If you notice your arch is becoming flatter over time, your heel is tilting more than it used to, or your shoes are wearing out in new patterns, these could indicate that your flat feet are worsening. Early intervention can often slow or halt this progression.

Asymmetry between your feet is another red flag. While it's normal for feet to differ slightly, if one foot becomes significantly flatter than the other—especially if this happens suddenly—it could indicate an injury to the posterior tibial tendon or other supporting structures that requires prompt attention.

Contact a healthcare provider or physical therapist if you experience any of the following:

• Foot or ankle pain that doesn't improve with rest
• Pain that limits your ability to walk, work, or exercise
• Visible swelling along the inside of your ankle
• Difficulty performing a single-leg heel raise
• One foot becoming significantly flatter than the other
• Knee, hip, or back pain that may be related to your feet

What Causes Flat Feet?

Flat feet can be caused by a weakening or lengthening of the posterior tibial tendon (the main arch support), stretching of foot ligaments, aging, previous foot injuries, obesity, certain medical conditions like rheumatoid arthritis or diabetes, and in some cases, genetic factors present from birth.

Understanding what causes flat feet helps in both prevention and treatment. The arch of the foot is maintained by a delicate balance of bone structure, tendon tension, and ligament support. When any of these components fail, the arch can collapse.

The posterior tibial tendon is the primary dynamic support for the arch. This tendon runs along the inside of the ankle, beneath the medial malleolus (the bony bump on the inside of your ankle), and attaches to bones in the midfoot. When you walk, this tendon lifts and stabilizes the arch. Over time, this tendon can become weakened, stretched, or torn—a condition called posterior tibial tendon dysfunction (PTTD), which is the most common cause of adult-acquired flat feet.

Several factors contribute to tendon and ligament deterioration:

Age-Related Changes

As we age, tendons naturally lose some of their elasticity and strength. The posterior tibial tendon may gradually stretch and weaken, reducing its ability to support the arch. Similarly, the ligaments that hold the foot bones in place can become lax. This is why adult-acquired flat feet most commonly develops after age 40, with the risk increasing with each decade of life.

Overuse and Repetitive Stress

Occupations or activities that require prolonged standing, walking on hard surfaces, or repetitive impact can accelerate wear on the foot's supporting structures. Athletes who participate in high-impact sports, healthcare workers who stand for long shifts, and others with physically demanding jobs may be at higher risk. This repetitive stress can cause microtrauma that accumulates over time.

Obesity and Excess Weight

Carrying extra weight places additional stress on the feet. The posterior tibial tendon must work harder to support the arch, and the ligaments experience greater stretching forces. Studies show that obesity significantly increases the risk of developing flat feet and can accelerate the progression of existing arch collapse. Weight management is often an important component of treatment.

Injury and Trauma

Acute injuries to the foot or ankle can damage the structures supporting the arch. A fall, ankle sprain, or direct blow to the foot can tear or stretch the posterior tibial tendon or the ligaments of the midfoot. Even after healing, these structures may not return to their original strength, leading to progressive flatfoot deformity.

Medical Conditions

Several medical conditions can affect the tendons and joints of the foot:

• Rheumatoid arthritis: This autoimmune condition causes inflammation that can damage tendons and joints throughout the body, including the foot
• Diabetes: Long-standing diabetes can cause neuropathy and changes in tendon structure that weaken arch support
• Hypertension: May affect blood supply to tendons, impairing their ability to heal and maintain strength
• Connective tissue disorders: Conditions like Ehlers-Danlos syndrome or Marfan syndrome can cause joint hypermobility and ligament laxity

How Are Flat Feet Diagnosed?

Flat feet are diagnosed through physical examination, including observation of foot shape while standing and walking, the single-leg heel raise test, and the "too many toes" sign. Additional tests may include weight-bearing X-rays to assess bone alignment, and in some cases, MRI to evaluate tendon damage.

Diagnosing flat feet typically begins with a thorough history and physical examination. Your healthcare provider will ask about your symptoms, when they started, what makes them better or worse, and how they affect your daily activities. They'll also inquire about your medical history, occupation, exercise habits, and any previous foot injuries.

The physical examination involves several components designed to assess the structure and function of your feet:

Visual Inspection

The examiner will look at your feet while you're sitting, standing, and walking. They're looking for the presence or absence of an arch, the alignment of your heel, and any visible swelling or deformity. The "wet footprint test"—where you wet your feet and step on a surface that shows the print—can reveal whether your arch is normal, low, or absent.

Single-Leg Heel Raise Test

This is one of the most important tests for evaluating flat feet. You're asked to stand on one foot and rise up onto your toes. A healthy posterior tibial tendon allows you to perform this movement smoothly, and your heel should turn inward (invert) as you rise. If you have difficulty performing this test, cannot complete multiple repetitions, or your heel doesn't invert properly, it suggests posterior tibial tendon dysfunction.

"Too Many Toes" Sign

When the examiner views your feet from behind while you're standing normally, they can typically see one or two toes peeking out on the outer side of each foot. In flat feet, the forefoot often rotates outward, making more toes visible—hence the name "too many toes" sign. This indicates the foot has collapsed and rotated as part of the flatfoot deformity.

Imaging Studies

While the diagnosis of flat feet can often be made clinically, imaging studies provide additional information:

• Weight-bearing X-rays: These are taken while you stand on your feet, showing the bones under normal loading conditions. Specific angles and measurements help determine the severity of the flatfoot deformity
• MRI (Magnetic Resonance Imaging): If posterior tibial tendon dysfunction is suspected, MRI can show the condition of the tendon—whether it's inflamed, partially torn, or completely ruptured
• CT scan: Occasionally used to evaluate bone alignment in more detail, particularly if surgery is being considered

What Exercises Help Flat Feet?

Effective exercises for flat feet include toe curls (strengthening intrinsic foot muscles), heel raises (strengthening calf muscles and arch), arch lifts (actively raising the arch while keeping toes flat), towel scrunches, and resistance band exercises. Perform these daily for 6-8 weeks to see improvement.

Exercise is a cornerstone of flat feet treatment. A well-designed exercise program can strengthen the muscles that support the arch, improve the function of the posterior tibial tendon, and enhance overall foot stability. While exercises may not change the bony structure of a flat foot, they can significantly reduce symptoms and improve function.

The key to success with exercise is consistency. These exercises need to be performed daily, and it typically takes 6-8 weeks of regular practice before noticeable improvements occur. Think of these exercises as physical therapy for your feet—they're simple to do at home and require minimal equipment.

Toe Curls

Toe curls strengthen the intrinsic muscles of the foot—the small muscles that originate and insert within the foot itself. These muscles play an important role in maintaining the arch during walking.

How to perform: While seated with your feet flat on the floor, curl your toes downward as if you're trying to grip the floor. Hold for 5 seconds, then release. Repeat 10-15 times per foot. Progress to doing this while standing for a greater challenge.

Arch Lifts (Short Foot Exercise)

This exercise specifically targets the muscles that lift and maintain the arch. It's considered one of the most effective exercises for flat feet.

How to perform: Stand or sit with your foot flat on the floor. Without curling your toes, try to lift your arch by drawing the ball of your foot toward your heel. Your toes should remain flat on the ground. Hold for 5 seconds, then release. Repeat 10 times per foot. This movement is subtle—your foot will appear to "shorten" slightly as the arch rises.

Towel Scrunches

This classic foot exercise strengthens the muscles along the bottom of the foot.

How to perform: Place a small towel flat on the floor. While seated, place your foot on one end of the towel. Using only your toes, scrunch the towel toward you, gathering it under your foot. Repeat 10-15 times per foot. To increase difficulty, place a small weight (like a book) on the far end of the towel.

Heel Raises

Heel raises strengthen the calf muscles and the posterior tibial tendon, both essential for arch support.

How to perform: Stand with feet hip-width apart, using a wall or chair for balance if needed. Slowly rise up onto your toes, hold for 3 seconds, then slowly lower back down. Perform 15-20 repetitions. As you get stronger, progress to single-leg heel raises, which are more challenging and more closely mimic the demands of walking.

Resistance Band Exercises

Using an elastic resistance band adds variety and can target specific muscle groups.

How to perform: Sit with your legs extended and loop a resistance band around the ball of your foot. Hold the ends of the band and gently pull to create tension. Point your foot away from you (plantarflexion), then flex it back toward you (dorsiflexion). Also practice turning your foot inward (inversion)—this specifically works the posterior tibial tendon. Perform 15-20 repetitions of each movement.

What Kind of Shoes Are Best for Flat Feet?

The best shoes for flat feet have firm arch support, a stable and reinforced heel counter, a roomy toe box, a sole that's sturdy but not completely rigid, and a removable insole that can be replaced with custom orthotics if needed. Good examples include quality walking shoes, hiking shoes, and certain athletic shoes.

Proper footwear is one of the most important—and often underappreciated—aspects of managing flat feet. The right shoes provide external support for the arch, help maintain proper foot alignment, and reduce strain on the posterior tibial tendon. Conversely, wearing inappropriate shoes can worsen symptoms and accelerate arch collapse.

Features of a Good Shoe for Flat Feet

Firm arch support: Look for shoes with built-in arch support rather than flat, cushioned insoles. The arch support should feel substantial when you press on it with your fingers and shouldn't collapse easily.

Stable heel counter: The heel counter is the back portion of the shoe that cups your heel. It should be firm and reinforced—when you squeeze the back of the shoe from both sides, it should resist compression. A stable heel counter prevents your foot from rolling inward excessively (overpronation).

Roomy toe box: Your toes need space to spread naturally. Shoes that are too narrow can cause the foot to compensate in ways that increase arch strain. Ensure there's about a thumb's width of space between your longest toe and the end of the shoe.

Sturdy but flexible sole: The sole should be firm enough to provide support but still allow natural foot movement. Try twisting the shoe—it should resist twisting through the middle (where the arch is) but flex at the ball of the foot where your foot naturally bends during walking.

Removable insole: Shoes with removable insoles allow you to replace them with over-the-counter arch supports or custom orthotics, giving you more options for customizing your support.

Shoes to Avoid

Certain types of footwear can worsen flat feet symptoms:

• Completely flat shoes: Ballet flats, flip-flops, and minimalist shoes offer no arch support
• High heels: Shift weight forward and increase stress on the forefoot and arch
• Worn-out shoes: Even good shoes lose their supportive properties over time; replace athletic shoes every 300-500 miles of use
• Overly soft, cushioned shoes: While they feel comfortable initially, very soft shoes often lack the structural support flat feet need

Orthotic Insoles

Orthotic insoles are specially designed shoe inserts that provide additional arch support and can help correct abnormal foot mechanics. They come in two main types:

Over-the-counter (OTC) orthotics: These pre-made insoles are widely available and relatively inexpensive. They can be effective for mild to moderate flat feet and are a good starting point for many people. Look for firm orthotics with good arch support rather than soft, cushioned insoles.

Custom orthotics: These are prescribed by a podiatrist or orthopedic specialist and are molded specifically to your feet. They provide more precise correction and are recommended for moderate to severe flat feet, when OTC options haven't provided adequate relief, or when specific biomechanical issues need to be addressed. Research shows that properly fitted custom orthotics can reduce flat feet pain by 50-80% in most patients.

How Are Flat Feet Treated?

Flat feet treatment follows a stepwise approach: starting with foot exercises and proper footwear, progressing to physical therapy and orthotics, considering immobilization for acute cases, and reserving surgery for severe cases that don't respond to 6-12 months of conservative treatment. Most people respond well to non-surgical approaches.

The treatment of flat feet depends on several factors: whether you have symptoms, the severity of those symptoms, the underlying cause, and how the condition is progressing. The good news is that the vast majority of people with symptomatic flat feet can be effectively managed without surgery.

Conservative (Non-Surgical) Treatment

Conservative treatment is always the first line of management and is effective for 90-95% of people with symptomatic flat feet. The approach typically includes:

Activity modification: Avoiding activities that aggravate symptoms, at least temporarily, allows inflamed tissues to heal. This doesn't mean complete rest—rather, it means substituting low-impact activities for high-impact ones while symptoms are acute.

Exercise therapy: As discussed earlier, a consistent program of foot strengthening exercises is fundamental to treatment. A physical therapist can design a program tailored to your specific needs and monitor your progress.

Supportive footwear and orthotics: Wearing appropriate shoes with good arch support, often combined with orthotic insoles, helps maintain proper foot alignment and reduces strain on the posterior tibial tendon.

Physical therapy: Beyond exercises, physical therapy may include manual techniques, ultrasound therapy, taping, and gait training to optimize how you walk.

Weight management: For those who are overweight, losing weight can significantly reduce the stress on foot structures and improve symptoms.

Anti-inflammatory medications: Nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen can help manage pain and inflammation during acute flare-ups. These should be used as directed and are not intended for long-term use.

Immobilization: In cases of acute posterior tibial tendon inflammation, a period of immobilization in a walking boot or short leg cast may be recommended to allow the tendon to heal.

Surgical Treatment

Surgery is considered only when conservative treatments have failed after 6-12 months of consistent effort, and symptoms continue to significantly impact quality of life. Surgical options vary depending on the severity and type of flatfoot deformity:

Tendon repair or transfer: If the posterior tibial tendon is damaged but the deformity is not severe, the tendon may be repaired or augmented with a transfer from another tendon in the foot.

Osteotomy: Cutting and repositioning bones to correct alignment and recreate the arch.

Arthrodesis (fusion): In severe cases, fusing certain joints in the foot can create stability and reduce pain. This is typically reserved for advanced deformity with arthritis.

Recovery from flatfoot surgery is significant—most procedures require 6-12 months before full recovery, including time in a cast or walking boot followed by extensive physical therapy. It's important to have realistic expectations and understand that the goal of surgery is pain relief and improved function, not necessarily a "normal" looking foot.

Can Flat Feet Be Prevented?

While genetic flat feet cannot be prevented, acquired flat feet can often be prevented or slowed by maintaining a healthy weight, wearing supportive footwear, doing regular foot strengthening exercises, avoiding prolonged standing on hard surfaces, and addressing foot pain early before it leads to compensatory changes.

Prevention is always preferable to treatment. While you cannot change the genetic factors that predispose some people to flat feet, there is much you can do to protect your foot arches and reduce your risk of developing acquired flatfoot deformity.

Maintain a Healthy Weight

Excess body weight is one of the most modifiable risk factors for flat feet. Every pound of body weight translates to several pounds of force on your feet during walking. Maintaining a healthy weight through balanced nutrition and regular exercise reduces the mechanical stress on your arch-supporting structures.

Choose Footwear Wisely

Your daily footwear choices have a cumulative effect on foot health. Consistently wearing supportive shoes with good arch support helps maintain proper foot mechanics and reduces strain on tendons and ligaments. Reserve flat, unsupportive shoes for occasional short-term wear rather than daily use.

Strengthen Your Feet Regularly

Just as you might do exercises to strengthen your core or arms, regular foot exercises help maintain the strength of the muscles that support your arches. Even a few minutes of foot exercises several times per week can make a difference over time.

Listen to Your Body

Foot pain is not normal and shouldn't be ignored. When your feet hurt, it's often an early warning sign that something is being overstressed. Addressing discomfort early—by modifying activities, improving footwear, or seeking medical advice—can prevent minor issues from becoming major problems.

Consider Your Work Environment

If your job requires prolonged standing, take steps to protect your feet: wear supportive footwear, use anti-fatigue mats when possible, take sitting breaks when you can, and consider compression stockings to improve circulation.