Today’s invention is inspired by the ice and snow of this Northern winter.
Rather than bolt spikes or crampons onto one’s shoes, perhaps an integral solution would work better.
A pair of boots would have an extra sole which splits down the middle and is hinged at either side.
Undoing the clips to split open this extra sole allows both the external sole halves to flap out and make contact with the icy ground. These flaps could be engineered so that when the wearer’s weight was applied, the flaps flexed elastically to provide extra grip between ridged undersurface and the ice/snow.
In deeper snow, these boots would act as snowshoes, spreading the weight and limiting the depth to which one’s feet could sink.