In any discussion of flat feet, one must first appreciate what is meant by a flat foot. It is not necessarily a foot in which the "arches are lost or flattened out," as is the popular conception.
For many years Whitman1 has been preaching the doctrine that the most direct of the predisposing causes of so-called flatfoot is a posture that simulates the deformity which may be defined as a persistent attitude of abduction. It is now believed that this simulating posture is actually the first stage of flatfoot.
Morton2 has aptly brought out the fact that it is the position of the os calsis as a means of regulating "balance" in the distribution of body weight that is of prime importance in the foot. The muscles of the foot are not weight-supporting but serve to balance the body weight on the foot or more particularly on the