Flat Feet (Pes Planus)

Types of flat feet

Flat feet in children

All babies have flat-looking feet because of fat pads and loose ligaments. Arches develop gradually during childhood, mostly by age 6 to 10. Flexible flat feet that do not hurt usually need nothing more than normal shoes and activity. A rigid or painful flatfoot in a child or teen may be due to tarsal coalition, an abnormal bony or fibrous connection between foot bones, which may need treatment.

Causes and risk factors

• genetics: flat feet run in families
• loose ligaments and joint hypermobility, including hypermobility spectrum disorders and Ehlers-Danlos syndrome
• posterior tibial tendon dysfunction: the main cause of adult-acquired flatfoot
• obesity, which overloads the arch
• aging
• pregnancy, from hormonal ligament laxity and weight gain
• injury, such as fractures or ligament tears in the midfoot
• rheumatoid arthritis and other inflammatory arthritis
• diabetes with nerve damage (Charcot foot)
• neuromuscular conditions, such as cerebral palsy and muscular dystrophy
• tarsal coalition in children

Posterior tibial tendon dysfunction

The posterior tibial tendon runs behind the inner ankle bone and supports the arch. When it becomes inflamed, stretched or torn, the arch gradually collapses, the heel tilts outward and the forefoot points out. It is most common in women over 40, and in people with obesity, high blood pressure or diabetes. Early symptoms are pain and swelling along the inner ankle. Later, pain can move to the outer ankle as bones press together. Without treatment, the foot can become rigid and arthritic. See posterior tibial tendon dysfunction.

Symptoms

Many people with flat feet have no symptoms. When they occur, they include:

• arch pain, heel pain or pain on the inner ankle
• tired, aching feet after standing or walking
• swelling along the inside of the ankle
• difficulty standing on tiptoe
• pain in the shins, knees, hips or lower back from altered alignment
• uneven wear on shoes, especially the inner edge

Diagnosis

A doctor or podiatrist will look at your feet while standing, sitting and walking. Common tests:

• Tiptoe test: standing on tiptoe should make a flexible arch reappear and the heel turn inward.
• "Too many toes" sign: from behind, more toes are visible on the outside of a flat foot.
• Single-leg heel raise: difficulty doing this suggests posterior tibial tendon problems.
• Calf flexibility testing.
• Weight-bearing X-rays: show the foot's alignment and arthritis.
• MRI or ultrasound: assess tendons. CT shows tarsal coalition.

Treatment

For painless flexible flat feet

No treatment is needed. Normal, supportive shoes and regular activity are fine for children and adults.

For painful flat feet

• Supportive shoes: firm heel counter, good arch support, cushioning and a slight heel.
• Arch supports: over-the-counter or custom orthotics.
• Calf and Achilles stretching: daily, if tight.
• Strengthening exercises: for the posterior tibial tendon and the small muscles of the foot, such as heel raises, towel scrunches and short-foot exercises.
• Weight loss if overweight.
• Pain relief: ice after activity, and acetaminophen (paracetamol) or anti-inflammatory medicine at the label dose.
• Physical therapy.

For posterior tibial tendon dysfunction

Early stages are treated with a walking boot to rest the tendon, followed by an ankle brace or custom orthotic and physical therapy.

Surgery

Surgery is considered for painful flat feet that do not improve with other treatment, rigid flat feet, tarsal coalition and advanced tendon dysfunction. Options include:

• tendon repair or transfer
• lengthening a tight calf or Achilles tendon
• bone cuts (osteotomies) to realign the heel and midfoot
• removing a tarsal coalition
• fusion of arthritic joints

Frequently asked questions

Are flat feet a problem?

Usually not. Most flat feet are flexible and painless and need no treatment. They become a problem when they cause pain, are stiff, develop in only one foot, or appear in adulthood due to a failing tendon. These need assessment.

Can flat feet be fixed?

Painful flexible flat feet usually improve with supportive shoes, arch supports and exercises, though the arch shape itself may not change. Adult-acquired flatfoot and rigid flatfoot can be corrected with surgery if other treatments fail.

Do children grow out of flat feet?

Most do. Babies and toddlers normally have flat-looking feet, and arches usually develop by age 6 to 10. Children with painful, stiff or one-sided flat feet should see a doctor.

What are the best shoes for flat feet?

Look for shoes with good arch support, a firm heel counter, a supportive midsole that resists twisting, and enough cushioning. Stability running shoes and shoes that accept custom orthotics are good options. Avoid completely flat, unsupportive shoes if your feet hurt.