Here are 3 illustrations that I'm working on for the upcoming (eventually) 4th Edition of my book, relevant to several of the current threads. I submit them for discussion and feedback....
They show the "perfect turn" that we've discussed represented at three typical levels of skier development. If you look closely, you will see that the fundamentals are identical for all three. The only differences are due to speed, steepness of the hill, and as a result, intensity and range of movements and forces involved. The movements are less dramatic at the lower levels for two reasons--the reduced forces and speeds don't require as much motion, and the skills and movements of the skier at that level are, naturally, less advanced.
(MODERATOR NOTE 12/31/2008: The following diagrams are new and updated. They may not exactly relate to the discussions that follow in the thread.)
There is a lot to see here--look closely! A few things to note, in all three illustrations:
1. The skis (and legs) rotate in the hip sockets beneath the pelvis, analogous to the steering of a car's wheels beneath the chassis. As a result, there is a subtle lead of the inside ski tip throughout the turn, passing through square or "neutral" in the transitions (frames 4, 12, and 20). The rest of the body parallels that inside tip lead--a line across the hands or shoulders would be parallel to the line across the tips. There is no rotation or counter-rotation of the upper body, and there is no blocking pole plant.
2. The skier steers the INSIDE ski tip INTO the turn, throughout the turn. While there is some skidding, especially noticeable in the lower Wedge and Basic Parallel levels, there is no PUSHING of the tails--no INTENTIONAL skidding. The skidding happens because the turns are tighter than the skis could turn purely by bending into an arc and carving, especially again at the lower levels, where neither the skills nor the forces involved are sufficient to tip and bend a ski into a tight, pure-carved arc. With greater forces and edge angles, the Dynamic Parallel turns show more carving, less skidding--because they can!
3. Both skis tip smoothly into the turn, progressively, from the start to the point of maximum edging (approximately frame 17). Then the edge angles begin to roll smoothly the other way, first reducing the angles to end the one turn, then RELEASING in the transition (frames 4, 12, and 20), and continuing to roll smoothly into the next turn. (Note that the ski does not need to be completely flat on the snow to release. It releases the moment its angle becomes less than the "critical" edge angle that we have discussed. Therefore, even the wedge turns, where the skis never become completely flat, initiate with an edge release.)
4. The skier's body (center of mass, indicated by the red dotted line) flows smoothly throughout the sequence, taking a shorter path than the skis, with the "crossover" in the transitions (frames 4, 12, and 20). The solid blue line indicates the path of the "balance point" or "center of pressure," the point on the snow where the skier's balance is focused regardless of stance width or ski length.
5. Related to #4, there is no active movement TOWARD the new outside ski (uphill) to create a weight transfer at the turn initiation. There is a weight transfer, though, as there is in a car, resulting from the forces of the turn (gravity and centrifugal force) pulling the skier progressively toward the outside ski as the turn develops. With the higher speeds (and of course, more accurate, skillful movements), the Dynamic Parallel turns show a complete weight transfer from quite early in the turn. The weight transfer is less complete in the lower speed turns, and develops more gradually. Regardless, all the turns flow through a moment of "neutral" where the pressure is equal on both skis. While I've illustrated this point in the transition frames (4, 12, and 20), in reality it often occurs later, especially at lower speeds, or on steeper slopes. Indeed, the timing and completeness of the weight transfer is hugely variable, at all levels. The weight transfers I've illustrated are typical, but not obligatory! Remember that, in these turns, weight transfer is an outcome of specific appropriate movements affected by many other variables. It is not a requirement, or an end in itself.
6. In short, these illustrations clearly show the "positive movements" that we've discussed--the signature of the "perfect turn"--as they appear at various skill levels with typical speeds, turn shapes, and condtions. They represent typical turns, not dogma! The movements, and their outcomes, will vary according to changing conditions, speeds, needs, intents, and whims of the skiers.
Have fun with these! I'd love to hear any comments or suggestions on how I could improve them.
PS--the skiers in these illustrations include Hermann Maier, Regine Cavagnoud, Jerry Berg, Gates Lloyd, Stephanie Sugars, Jennifer Metz, and myself.
[EDIT 3/4/2012--frame numbers in descriptions have been updated to correlate to the new illustrations added in 2008. In particular, "turn neutral" is represented now in frames 4, 12, and 20, not frames 5 and 18 as in the previous illustrations. --Bob]