The present invention is directed to an adjustable footwear system to provide varying degrees of tightness in different areas of the footwear before and after the footwear is received on the foot. The footwear is, in its initial form, tightest on the inner cavity with an upper comprised of one or more elastic materials. An extensor system is activated to create a rigid infra-structure to open a cavity of the footwear between the upper and an insole. A decrease of pressure in the extensor system decreases the cavity volume and allows for the elastic upper to apply pressure to the foot.