A mattress for the sole of the foot and a lintel for the architecture of the whole shoe
Although it is not the only component on which the comfort of a shoe depends, the insole is clearly a key one: beyond the aesthetics, beyond the fine materials used to make the upper, beyond the brand and the emotion a shoe can unleash, if an insole does not match well with one’s foot, usually the shoe is discarded and another pair is tried on.
Cushioning, perspiration, sweat absorption, stability, posture, the durability of the shoe: these are all factors that depend on the insole, which is the part in direct contact with the plantar area of one’s foot, which is as important as a mattress for a good night’s sleep or a well-designed lintel for the stability of a structure.
If, for centuries, shoes were uncomfortable, the “fault” is also the insole’s. It seems that the inventors of the first insoles were not the shoemakers, but landlords of inns, encouraged by the continuous complaints of pilgrims who travelled on foot. Initially, animal furs were used, then, with the evolution of footwear techniques, the industry moved on to leather and synthetic materials.
Images from “L’impresa calzaturiera”, di A. Morlacchi, G. Bellotti, F. Gambino, Editrice San Marco srl, Trescore, Bergamo
The insole is not to be confused with the orthotic arch support, which has specific orthopedic characteristics, is usually purchased separately, is removable and is used to increase comfort, but especially to correct or intervene in particular foot- or posture-related pathologies.
The insole is in turn made up of three elements: the footbed, which covers the entire plantar area and can be made of leather or of cellulose-based or synthetic materials; the heel seat lining, running from the heel area to the plantar area, thinning more and more as it goes along, which is essential to keep the heel firmly in place and is often made of fiber cardboard; and the shank, which is made with a steel foil and constitutes the “vault” that supports the arch of the foot.