Yep. Wedge Christie no stem.
The wedge is also a "gliding wedge", narrower, not a "braking wedge" which is very wide and more used for stopping at very low levels up to high levels. Snowplow is not used as a term because it usually conjures up a braking wedge which is all about stopping. Snowplow stances of yore were quite wide. It is also hard to make a turn with a wide wedge. Though people often don't believe it One ends up with way too much weight on one ski, the other gets hung up, people throw themselves around, get way back etc. It's often the uphill ski with too much weight because people are leaning away from downhill because that's the scary part. The inside gets hung up, tip goes up in the air because they're back, then they might lean towards it again with body twisting around cause that's now uphill, and fall. Using a gliding wedge makes learning everything easier but shallow terrain is key.
A large wedge will in general have people be back on the boot cuffs even in a straight run. It's usually a go to defensive position. Once it takes hold it's tough to break. Low angle terrain is the best way, but often people - kids usually, get so good at it they can make it down quite steep terrain in a wide wedge, aka "power wedge". So they see no need to ski easy terrain. Usually power wedges are painful for adults to keep up for very long.
Important point in the wedge christie is skis are made to "match", be parallel, by steering the inside ski not by sliding the tail down towards the outside ski tail- called "closing". The tips are guided in the direction one is going. That's pretty much modern skiing right there - guiding the tips. In matching skis for a wedge christie the tips open up and the distance between feet remains the same. In closing, the tips are roughly the same distance apart as the wedge, (they open a little more usually), the feet come closer together.
Tails sliding closed is not uncommon to see even in advanced skiers as their default method.
Illustration Bob Barnes
Illustration Bob Barnes
The physics stuff is getting ridiculous. I don't see the relevance and a lot of it is wrong.
Maybe he'll come out and talk about it, cause I don't get it, but Jamt has talked about we don't accelerate at the end of a turn.
Also, forces are often the greatest at the bottom of a turn because of the direction change across the slope. Even if one ends up on the heels at the very end, just before one is often the most forward- flexed into the boots, of the whole turn.
It's not required to know the physics of what one is doing. Does an ice skater know all about conservation of angular momentum and whatever else is involved in a routine? Does someone doing tricks off jumps know the physics of the spins? Does one need to know the physics of a frisbee to make a good throw? (Is it even understood how it flies?)
More interesting is the physiological part of being either too back or too forward.
The aft technique we see with the posted montage of Ligety in slalom is possible only because he's able to pivot the skis quickly and have them switch sides. You couldn't do that in a gs type turn because there's too much distance to the next gate and you're going too fast.
Sometime it is better not to know too much physics. A little knowledge can be a dangerous thing. For example I was good at helicopters (aerial 360's--I started a few weeks after I first saw Art Furrer demonstrating one in a ski magazine article in the late 60's). When I later wanted to go for two rotations I made the mistake of trying to use what I knew about physics, rotational momentum and ice skaters, to speed up my rotation so I could get around quicker. So instead of doing what I knew about one rotation and just holding the rotated position about three times longer before counter-rotating the finish I decided that if I started in a wider stance, once in the air I could pull my feet together as well as my arms to further speed up the spin. Good in theory maybe, but what I didn't realize was that my groin and inner thigh muscles would not be strong enough to bring that rotating momentum of legs, skis, and boots back together. The result was an off balance wobbling spin that ended up a quarter rotation short. Landing that way was hard on the knees and neck. The next time I tried it I used what I already knew from doing singles and succeeded, but the landing blew off one of my skis. Good thing I already knew how to ski on just the other one.
In your diagram above it looks like Closing is what I'd call a Stem Christie (total weight shift to one ski, close and skid). I'm having a problem understanding how the Matching diagram works though. How can the inside ski turn that way when it is still on the inside edge? What is driving that inside ski tip? Does this encourage leading with the inside edge change, like I try to get skiers to do? My objection to the Wedge is that when taught first it is learned while the skier is afraid. At least with adults (kids do the gliding wedge naturally and I thought Lemaster had a good explanation of why-- it is harder to balance a short pencil vs a long broomstick). Things you learn when afraid are stored in the amygdala and can never be forgotten (excepting maybe with the help of Alzheimer's). I think that is the reason that so many skiers have a real hard time breaking away from using both inside edges at the same time and tend to revert to it again whenever they get nervous. While this may provide the ski schools with years of income while the student works on getting over that habit, I don't think, in the long run it is good for the skier. I can see how it might help a ski school in the Darwinian competition for the most student dollars, and thus survival, though.