Inner sole shaped to fit the foot - is made of permanently compressed material esp. polyethylene producing a variable density

摘要

The inner sole is shaped to fit the lower part of the foot and is made of a material that can be permanently deformed. This produces a density that varies according to the part of the sole, and is permanent and is not affected by the pressure of the foot. The density is at a max. under the heel bone and at a min. at the top of the arch. Under the ball of the foot the density has an intermediate value. Pref. the inner sole is prepd. by compressing a wedge-shaped piece of polyethylene foam in a mould.