Flat foot is a structural variation of the foot where the foot arch (thanks to www.weightlossexercisediet.com for the images) at the inner aspect of the foot is flattened. This leads to foot arch and foot pain. Sometimes this is falsely diagnosed in infants as they have a prominent fat pad in the medial longitudinal arch.
However, with tiptoeing the arch is normalizing showing that it was a false diagnosis of a “flat foot” and the infant really has a normal infant foot. This peculiarity and the associated wide-based gait and “foot pronation” normalizes itself at the age of 2.5 years (Ref.2). The child’s foot changes its morphology and becomes more like the adult foot by the age of 8 years. A good pair of children’s shoes will be all that is required. Diagnostic tests usually are not needed as the diagnosis is based on the clinical examination. If beyond the age of 8 years there is a foot arch, which is fallen at the inside of the longitudinal arch, then this needs to be treated with appropriate insoles and this will usually take care of the foot pain (Ref. 1).
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2. The Merck Manual, 7th edition, by M. H. Beers et al., Whitehouse Station, N.J., 1999. Chapter 270.
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