Abstract: A ski boot, integrally molded from polymeric material, has a base or bottom portion and a leg or top portion interconnected at the heel by a flexible link which is corrugated and therefore extensible over the major part of its width. Lateral flaps on the leg and on the base carry coating snap fasteners which interengage on a horizontal pivotal axis in the region of the ankle, the extensible link being substantially tangent to an imaginary circle centered on that axis.