There are some answers above that may help. But I think most miss the essence of the problem. I boil almost all my lessons down into three areas:
1) Turn shape. You control the turn shape. The turn shape should be the primary contributor to speed control (of course relative to the slope). Turn shape is crucial at every level of skiing.
2) ACTIVE ***INSIDE*** SKI. This is where most skier with a "wedge problem" go wrong (and the subject of this thread). Skiers are too often taught that the outside ski is the dominant and active ski. It really isn't... or at least shouldn't be. I could write a book on just this one subject. This is where I'll focus down below.
3) Lateral body position [where the center of mass is between right and left skis]. I don't teach in terms of weighting or pressure, but BODY POSITION which allows pressure to occur correctly and naturally. Proper lateral body position helps to unlock the feet and allow them to edge and flatten the skis at will with a quiet upper body. As far as pressure is concerned, once the turn shape begins (direction change) centrifugal force takes over and proper body alignment/position between the skis, and ultimately along the line-of-action (LOA) later on when the forces build and require more resistance. I then can talk about adjusting pressure from leg flexion/extension.
What causes the snowplow (converging skis) is the notion that the outside ski should be pushed out and turned (rotary push-off). It works... for beginners. But then you have to "unlearn" it. PSIA, while it advocates the "gliding wedge" where students are encouraged to use the inside ski, then goes on to talk about matching the inside ski at the end of the turn; then earlier in the turn, etc. (Wedge Christie I and II). I think instructors often assume that a new skier must begin with a wedge, and often errantly encourage the convergence. IMO this is long outdated teaching/learning technique and installs movement patterns that are counter to advanced and expert skiing. Somehow the OP got into the rotary push-off technique and now must unlearn/relearn to progress. It is the INSIDE SKI should control the turn shape, or path the skier wishes to travel, not an active, dominant outside ski. Use the left ski to go left and the right ski to go right. You can begin the turn by tipping the outside baby toe of the inside ski to the outside edge (left ski-left edge/right ski-right edge). Alternately you can attempt to steer the inside ski through the path. EDGING AND STEERING ARE MUCH THE SAME MOTION, with the femur rotating in the hip socket. It's just that the edge tipping motion can help the skier learn how to leverage forces from the feet (rather than the concept of edging from the knees). In truth, more often than not, edging and steering (rotary) are "blended skills", where we often use them both, in varying proportions. When you utilize the inside ski, the snow will create resistance (torque) which will go up the inside leg, across the pelvis and down the outside leg. IN OTHER WORDS... THE TORQUE OF THE INSIDE POWERS THE OUTSIDE SKI- WHICH WILL FOLLOW ALONG AUTOMATICALLY. Result: INSTANT (or near instant) PARALLEL TURN. Just add a little forward motion to make it happen.... At very slow speeds a slight wedge shape may appear, but disappears automatically once the skier is no longer skiing at a snail's pace.
... Now you can look at other methods to sort of accomplish the same thing. But I prefer my method because in using that inside foot actively in within the shape of the turn, not only does it help to turn the outside ski, but almost automatically creates the separation of upper and lower body, because the upper body remains quiet and the feet do all the work.
But don't ignore #1- turn shape. That is the key to improvement at every level.
I probably missed something. Please let me know if I was unclear about anything. But in essence, that is the Ski World, According to Vindibona.
