Ski boot, in particular for ski mountaineering

A ski boot adapted for ski mountaineering, said boot comprising:

• a) a rigid plastic shell with a sole configured to support a foot of a skier;
• b) a leg portion configured to fit about a leg of the skier;
• c) bosses disposed on an exterior portion of said shell;
• d) recesses on an interior portion of said shell configured to receive the bosses and allow said leg portion to pivot relative to said shell;
• e) a first cut extending longitudinally and formed in an upper portion of said shell to define an aperture for receiving the foot of the skier, said first cut laterally spacing opposing portions of said shell;
• f) at least a second cut extending transversely across said shell to define a cavity therein, and opening into said first cut;
• g) a stiffening plate coupled to said shell and partially covering said first cut and substantially covering said at least a second cut, said stiffening plate being provided with a longitudinal slot overlapping a hole in said shell, and
• h) a rotatable peg inserted through said longitudinal slot and said hole, said rotatable peg having a head of substantially parallelepiped shape of a length corresponding to a distance between two stop appendices provided on an outer surface of the plate on opposite sides of said slot,
• wherein flexing of a foot of a skier is prevented when said head is aligned longitudinally between said two stop appendices, and wherein the flexing of the foot is enabled when the rotatable peg translates within the longitudinal slot such that the head is disposed laterally from said two stop appendices.