A device including a cover and a shaft inserted in the thickness of the front portion of the sole, and constituting a journalled system, adapted to ensure control of the flexural rigidity of a shoe, in particular a snowboard boot, or adapted to ensure the protection of the front surface of the shoe, partially or in its entirety. All of the elements forming the system can be removable. The journal which it determines provides the cover with a front-to-rear mobility which is presented, in closed position, against the front surface of the shoe. Connected to the latter by a retaining mechanism specific to the shoe, the cover offers, due to the properties and the shaping of its constituent materials, a resistance to the crushing and flexural and torsional deformation of the shoe in its front portion during use.