I was skiing with an instructor friend of mine the other day, and we were talking about high performance dynamic turns and using the top of the turn to gain control. This is a topic I have brought up a few times before, and I continue to struggle with it. She told me that getting to the new downhill ski as early as possible, and getting it on edge was critical. Once the edge is set, rotary is added to make the ski turn tighter than it would if you just let the sidecut do all the work.
So I've been thinking about this for the last few days now, and it seems to me that at higher edge angles, steering through rotary doesn't quite make sense. With a flat ski, and at lower edge angles, we turn the feet and legs by rotating the femurs in the hip sockets. When our skis are tipped to higher edge angles, that same rotation of the femurs will essentially be pushing down into the surface of the snow rather than along that surface. In other words, a flat ski will easily pivot, but a ski tipped to 90 degrees would just push the sidewall of the tip down into the ground. The closer we get to 90 degrees, the less we can pivot.
So how do we generate steering forces at high edge angles if we can't do it from the femurs?