Flat feet

Flat feet (pes planus) means the arches on the inside of the feet are flattened — the whole sole touches the ground when standing. It's common and often completely normal. Many people with flat feet have no pain or problems at all.

When is flat feet a problem?

Children under 3-5 years often have flat feet because the arch hasn't fully developed yet — this is normal and no treatment is needed. Most children's arches form by age 6.

Flat feet become medically relevant mostly when they cause:

• Foot, arch, or heel pain, especially after prolonged standing or activity
• Leg, knee, hip, or lower back pain
• Feet tiring easily
• Shoes wearing out unevenly
• Trouble with certain sports or prolonged walking

Causes

• Genetic / familial — runs in families
• Flexible flat feet (most common type — arch appears when not weight-bearing, flattens when standing)
• Overweight or obesity — extra load flattens the arch
• Pregnancy — ligaments relax; some women develop flat feet that persist
• Injury or arthritis of the foot
• Adult-acquired flat foot — often from posterior tibial tendon dysfunction, more common after middle age

Treatment

Flat feet without symptoms need no treatment. If they cause pain or functional problems:

• Supportive, well-fitting shoes with good arch support
• Over-the-counter or custom orthotic insoles
• Stretching and strengthening exercises (calf stretches, foot-arch exercises, tibialis posterior strengthening)
• Physiotherapy
• Weight loss if overweight
• Pain relievers for short-term symptom management
• Rarely, surgery for severe rigid flat feet that don't respond to other treatment

See a doctor if you have foot pain that isn't improving, difficulty walking, a child whose feet remain flat and painful, or asymmetry (one foot flat, the other not).