a shoe comprises a flexible outersole , an insole and an upper , the upper being formed from a flat thermo plastic rubber blank , a toe cap first being fabricated in the blank by means of a teacup crease special - use sewing machine , the blank or preform subsequently affixed to a last and joined by a second special purpose sewing machine , or disc feed overseaming machine , to a non - woven fabric midsole or insole , substantially completing the upper . thermal processing on the resulting preform completes processing of the upper without use of an insole board . a third element of the shoe , the outersole , is unitary in construction , and equipped with a unique pattern of intersecting grooves , as well as an external bridge or instep support in lieu of an inner steel shank . following bonding of the upper and the outersole , a shoe of unique flexibility is produced , while still providing adequate protection to an active user &# 39 ; s foot .