US Patent 7966751 Sole with extensible structure

Sole with stretchable structure, in which the forepart is associated with a stretchable material to fit differing foot widths easily; and footwear equipped with such a sole. The sole base (1) comprises openings (4) in which the lugs (3) of the stretchable part (2) are positioned in a sealed manner. The insole (5) comprises a deformable structure (6) in its forepart. When the wearer's foot is put into a footwear article provided with such a complex, it exerts pressure on the edges of the upper (10) thus causing deformation of the sole, which avoids feelings of compression of the foot.