Infants are born with a fat pad in the arch are making their feet appear flat. The key word is “appear” because the shape of the foot is determined by bone structure, not the soft tissues.
Arch height refers to the architecture of the foot, that is, one may have an arch which is high, low or medium. One may have a low arch which is very stable or a high arch which is not stable but rolls inward, also known as “pronation.” All feet need to roll in to a certain extent for the purpose of absorbing shock but excessive pronation or overpronation can be a problem.
The clinical concern is foot stability more so that arch height. A foot that overpronates or rolls in excessively can delay walking and lead to juvenile bunions (enlarged growths on the big toe joint) and reduced ability to push off (propulsion).
Overpronation may be caused by ligamentous laxity or too much flexibility in the arch joints, by congenital
deformities such as extra bones in the arch, and occasionally genetic problems.
Treatment options for problematic flat feet or significant overpronation include:
1) Modified shoegear with arch support and wedges on the inside (medial wedges) to reduce the amount that the feet roll in.
Prefabricated orthotics can be used in milder cases. Custom foot orthotics may be needed in more advanced cases including the UCBL (University of California at Berkeley) design. Another design is known as an SMO or supramalleolar orthotic. It is based on the idea that an orthotic that goes up higher works better. We find that when a UCBL is well made, the need for an SMO is uncommon.
Knock knees (genu valgum) can be worsened by the feet rolling in or overpronation.