Abstract: A device for modifying the pressure distribution of a ski over its gliding surface. The ski has a base and two binding elements. It further includes a long stiffening member which extends above the base of the ski and which has opposite ends affixed to the ski by base plates. Furthermore, the device includes a calibration device to induce a compression stress in the stiffening member that can vary between two values depending upon the presence or absence of the boot. According to a preferred embodiment, the calibration device includes a toggle joint mechanism constituted by a pair of journalled levers, one of the levers bearing the braking arms for the ski. The invention also is directed to a ski brake.