The arch, or instep, of your foot will normally not touch the floor when you stand barefoot. Some people have flattened arches and this may have always been the case since they were young or may develop over a variable period of time.
Most people with have a period of discomfort over the arch and inner side of their ankle If you have noticed that your arch has flattened, this may be associated with pain over the arch itself (and this discomfort may have been present for sometime before your foot shape changed). You may also have pain on the outer border of your foot and ankle. Usually your heel will also start to become more prominent to one side and in more severe cases your foot may start to point outwards.
The cause of this is overload to the structures on the inner side of your ankle and foot, both ligaments and tendons. Initially your foot will be flexible in that it can be pushed back into its normal position. In this early stage treatment with insoles can be very effective at relieving discomfort.
If the condition progresses, your foot may become rigid. This means that it can no longer be pushed back into a ‘normal’ shape. Insoles can still be effective but cannot reshape the foot at this stage.
Surgery is sometimes recommended in the early stages to reduce inflammation in the associated tendons. In the later stages, more complex surgery may be offered. The flexibility of your foot largely determines the type of surgery that can be performed. The goal of surgery is pain relief and may not restore the natural shape of your arch.
The operation can take a long time to recover from completely (typically around 12 months) and you are likely still to require use of the insoles even after the procedure.