Quote from Masters Racer:I think that the body was fairly steady, it hasn't moved much through frames 4 and 5. The skis moved away from the CoM because they were pushed (extension), not because they were rotated. The rotating of the femurs is simply necessary to keep the skis parallel to the snow.
I don't disagree with any of that. To expand on the part I just snipped, while the body was "fairly steady," the right side does come forward somewhat...so you have a movement of the body to counter rotational forces, not add to them.
Now I really like your use of the term "athleticism" to describe this turn. While some people on the internet try to focus on the fact that some (many) turns in a race aren't perfectly carved and then pitch "pivots," or "branded" steering or whatever the new flavor is, as a key to modern advanced skiing, the hard part for racers is learning to use the sidecut of the ski to control things as much as possible -- and if they can do that, they as athletes pretty much already can skid, drift, skivot or stivot a turn where needed. http://www.nastar.com/community/index.php?showtopic=2534
Steve Nyman in the linked thread: "To be frank. DONT STIVOT unless you have to. Being able to carve and go direct is way faster. We never practice the stivot and it isnt fast. Like Bode said is is a method to control speed. You carve to gain speed and you stivot to slow down. We never train it it is just something that happens. You learn it when you learning how to wedge as a beginner skier."
Obviously some recent races have been pretty well known for being stivot-fests, due to a combo of the way the course was set and lots of chemicals, to the extent that in some cases there've been course-specific skis used, which doesn't really help anyone. The majority of racers haven't been enthused by that, and it's made for some ugly skiing that's boring to watch. It's a phase, not something that changes the basics of their technique or has them all of a sudden incorporating "active rotary" as a mainstay of their skiing.