Abstract: A safety ski boot structure is described that allows a skier to flex his lower leg relative to his foot in forward, rearward, vertical, rotational and lateral directions. The structure includes a shoe member and a cuff member that are interconnected by helical compression springs. The springs are designed and arranged so that relatively moderate force is required to pivot the cuff members forward and back so as to enable the skier to readily execute turns and accommodate to varying terrain. The springs are designed and arranged so that a relatively large force is required to pivot or move the cuff member laterally or rotationally to enable the skier to readily control the edges of his ski while enabling lateral or rotational movement of the skier's leg should the skier fall or hit an object. Such a lateral and rotational feature minimizes the likelihood of leg breakage.