My discovery this week concerns the hollow of the blade: I am concentrating on skating on the hollow. In one sense this description is not quite right, because the weight is distributed over various parts of the ice skate blade, but primarily on the rocker. But I find it useful to concentrate on how weight is placed to put consistent pressure on the hollow part of the edge, typically at the rocker.
Each figure skate has two edges: the inside edge and the outside edge. Basic skills includes learning how to do turns with each edge. But in truth each edge has two sides to it. There is the outside part, and the part in the middle of the two edges: this is known as the hollow. When the blade is sharpened, the depth, or radius of the hollow can be set. A shallow hollow is used for figure eights, while a deeper hollow is used for freestyle.
Some time ago, I had Dan Petrie, who sharpens my skates, begin to move me towards a shallower hollow. I think I started at 1/2 inch, and then moved gradually up to 3/4 inch. I probably moved too quickly, as I did not understand how to use the edge properly. My coaches wanted me to move in that direction, but not too fast. The problem is that one will skid and slide sideways with a shallow hollow, until one learns how to use the edge better. I moved to a shallow hollow in 1/16 inch increments, over about a year. In time, I got more used to the shallow hollow, and began to use it better. After a while, when doing basic circle eights, at times I could feel the curve of the circle through my blade. What I did not understand was that it was the hollow I was feeling. I also did not realize how crucial that was. Now I have a much better idea.
The body of the skater should be bowed out from the center of the circle. This begins with the blade on the ice, and extends upwards to the hips through the torso and to the head. With weight on an edge, a skater moving forward on that edge will curve naturally, due to the curve of the blade. By being bowed out from the center of the circle, a steady pressure will be placed on the hollow side the the edge. Thus, on an outside edge, the medial, or hollow side, will be towards the outside of the circle. This is the part of the blade that one can feel curve below the foot. If the pressure is firm and steady, the curve will be consistent and true. Similarly, on an inside edge, the medial part of the edge, again the hollow, will be in contact with the ice, and will likewise guide the curve. To control skating, the torso bows up and out from the edge; control the posture to control the pressure on the hollow, and thus control the trueness and consistency of the clean edge. Posture is thus central to clean edges.
The challenge then is to keep this pressure steady on all edges, and then with changes of edges.