These so-called glissen – cow or horsebone skates – are over 1000 years old. In medieval times they enabled the users to slip-slide to their destinations via the frozen-over waterways, which was often faster than travelling by road in wintertime. For propulsion they used two ski-pole-like sticks, as the skates could not be strapped on so tightly that they allowed the skaters to push off with their feet.
Bone glissen, A.D. 600-100. Click on the image to see a larger version
The skates were attached to the user’s shoes with a narrow leather strap which was passed through the small hole in the bone. The skates could also be mounted under a sledge, the sticks served the same purpose as for skating.