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Flat Foot Deformity


The human foot normally has two arches, one from heel to toe and the other across the foot. When these arches are lower or non-existent, this is referred to as ‘flat feet’. Flat foot deformity can be either natural or ‘pathological’ i.e. caused by another condition. It affects adults and children - when discussing the condition in relation to children it is referred to as ‘paediatric flat foot’ as opposed to ‘acquired adult flatfoot deformity’ (AAFD).



Flat foot deformity often has no clear cause and it is possible that the condition is inherited. In adults the specific cause is generally problems with a tendon – the posterior tibial tendon. Where either an injury or degeneration over time affects this tendon, increased stresses on this tendon and surrounding ligaments results in a flattening of the arches.

In older children (10-12) a condition known as ‘tarsal coalition’ where the bones in the foot fail to properly separate, can cause painful flat feet.


It is perfectly normal for babies and toddlers to have some degree of flat feet, but this should disappear as they grow. If, however the feet are asymmetric or there is any pain or restriction in movement, this may indicate an issue. Symptoms present in young children may include…

  • Difficulty walking (or a change in the way the child walks).
  • Pain or tenderness in the foot (and sometimes in the knee and leg as well).
  • Lack of enthusiasm and / or of energy connected to physical activity.
  • Problems with wearing shoes.
  • Tilting of the heel outwards.

In adults the following symptoms may be present…

  • Pain / tenderness in the ankle or the rear part of the foot (the ‘hind foot’) or to the rear of the inside ankle (where the posterior tibial tendon is located).
  • Mild pain when walking or playing sport.
  • Increase in discomfort when wearing shoes and / or uneven wearing of shoes.

and at later stages…

  • Progressive flattening of the arch of the foot.
  • Progressive deformity of the ankle and/or rear section of the foot.
  • Development of arthritis.
  • Development of pain in the outside of the ankle.

Tests / Diagnosis

Diagnosis initially involves an examination of the foot and an observation of the patient when standing and sitting and when walking. The doctor may also need to examine the knee and the hip. There are a number of tools that are used to make an accurate assessment of the affected foot or feet. In some cases, x-rays may be required.

Non Operative treatment

Treatment for flat foot does not always require surgery. A podiatrist and physiotherapist can be very helpful in implementing treatments such as…

  • Supportive footwear and arch support orthotics.
  • Taping and braces.
  • Simple pain killers like paracetamol or non-steroidal anti-inflammatories.
  • Exercises to stretch the Achilles and calf muscles, or strengthen the Tibialis Posterior and small muscles within the foot.

Related Information

Tibialis Posterior Tendon Reconstruction
Acquired Flatfoot