The 5S version of alpine skiing fundamentals we refer to comes from the five Skiing Skills of Canada’s CSIA. Some people call them the “Five Divine Skills of CSIA,” but my understanding is that they are simply a classification of alpine skiing fundamentals. All movements, from the snowplough to the semi-plough to carving, always revolve around these core elements. Some systems may categorize them into four or six, but the essence remains the same.   As the saying goes, the mistakes made by skilled skiers are often the same as those made by beginners, and having your weight too far back is a perfect example.
Oldzhang, Red Master, and other fellow skiers provided some interpretations of this not long ago. In this post, I’ll share my own summary, with many details drawn from official materials and instructional sources.
    1. Stance and Balance (Posture and Balance):
    The term “stance” here refers to how the various joints of the skier’s body are aligned. A good stance should be stable yet flexible, allowing you to continuously adjust your balance while skiing.
    Balance, simply put, is your ability to “not fall.” In CSIA’s physics-based approach, it’s referred to as the relationship between the Base of Support (BOS) and the Center of Mass (COM). Your feet, which serve as your base of support, should be in the correct position to support your center of mass.
    North American technique does not emphasize distinctions between “high, medium, and low” stances, but instead uniformly adopts what is called the athletic stance. Throughout the ski run, based on pressure control (see below), you dynamically adjust the height of your stance—releasing or increasing pressure. At rest, your calves are slightly bent, your upper body is parallel to your calves, and your shoulders are positioned ahead of your hips. All joints remain slightly flexed. One golden rule to remember is: “Your shoulders should always be above your knees.” This stance is also the foundation of CSIA technique.
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    Stance width can vary, and this too is a dynamic process. You decide the width of your stance based on snow conditions. On groomed runs that are harder and flatter, you’d use a standard stance roughly shoulder-width apart; on harder ice, you’d go wider; on softer snow with lots of bumps or chopped-up snow, you’d use a narrower stance.   The width of your stance depends on the need for balance—wider on ice for more stability, narrower on soft snow to maintain better balance. Everything is determined by function.
    Maintaining balance involves movement across four planes: fore-aft (front to back), up & down (vertical), side to side, and rotational. The specific technical theories won’t be covered here. Beginner to intermediate skiers need to actively think about finding balance, advanced skiers develop an instinct for it, and top-level skiers can even anticipate changes in balance for the next move and proactively adjust to maintain stability. All joints should be in continuous, dynamic motion across these planes, flexibly adjusting rather than being rigid.
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    Keep your hands open and extended forward and outward—some degree of front-to-back movement is acceptable. It’s like walking a tightrope, where you can swing your arms to maintain balance.
    Keep your center of gravity centered—not too far forward, nor too far back—right on the sweet spot of your skis. The ideal state is when you can just feel the tongue of your boot. Being too far forward (excessive pressure on the tongue) or too far back (pressure on the heels or back of the boot) will affect both your balance and your turning ability, which we’ll discuss next.
How do you know if your center of gravity is centered? You can test this from a stationary position, or during the transition between turns. Jump slightly, straightening your legs. If your tails lift and your tips touch the ground, your weight is too far forward. If your tips lift and your tails are on the ground, you’re definitely too far back. The ideal scenario is when the entire ski lifts off the ground simultaneously. Some exercises, such as pressing hard against the tongue of your boot, are corrective methods designed for skiers whose weight is too far back.

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2. Pivoting (Rotation)

The rotation referred to here involves the active turning of the lower body only, while the upper body (including the hips) remains stable.

Pivoting is your ability to actively rotate the skis from side to side (which is why some techniques refer to this fundamental as the rotary skill). As you rotate the skis using your lower limbs (from ankles to thighs), a natural separation between the upper and lower body occurs.

To get a sense of pivoting, try this: lie on the ground wearing your ski boots, lift the part from your knees to your feet, and bendyour knees,then rotate both feet in sync. That sensation is what pivoting feels like.
Here’s a great video from PSIA that explains this movement:
http://v.youku.com/v_show/id_XNDQ1ODMzNTg0.html.
There are slight differences in some of the details, but that’s not the main point.

- Pivoting can be done simultaneously with edging. For example, as you gradually edge your skis from tip to tail, you can still pivot.
- The tighter the turn, the higher the demand for pivoting.
- Rotating your legs can make your turns smaller and can also be used to change your current turning direction (such as combining carved and skidded turns).
- Counter-rotation is not an active movement, but rather a natural result of good pivoting and edging.   To some extent, counter-rotation (counter-rotation) can physically help twist the skis, but this method is not encouraged. Excessive counter-rotation can put too much weight on the uphill leg.
- Pivoting is closely related to the position of your hands. If your hands aren’t spread out, you’re likely to turn by relying on your upper body, which leads to a lack of separation between upper and lower body—an incorrect movement.
- Similarly, for the same small turn, if the ski’s natural turning radius is smaller, you’ll need less twisting action.

To practice pivoting, hold your ski poles out horizontally to form a “window,” and make continuous turns on a steep slope while keeping the scenery within the window unchanged. In other words, keep your upper body facing the same direction. If you practice following a target, you’ll also achieve a similar upper-lower body separation.
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3. Edging (Carving Edge)

First, we need to dispel a commonmisconception: that learning edge control is for learning carving; that edge control means riding on edges, which is the same as carved turns; and that you don’t need to engage edges when riding in powder. These are all incorrect. Simply put, edge control means tilting the ski’s edge to create an angle with the snow surface. For example, parallel braking and traversing both require some degree of edge engagement. Even when sidestepping uphill or using the wedge christie or herringbone technique, you still need to tilt the edges. The difference between edge control and carving is whether, after tilting the edge, you let the ski’s sidecut guide your path rather than manually turning the ski. True carving means you “tell” the ski which direction to go, and it follows through, carrying you along.
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Edge control relies on inclination, which can come from the ankles, knees, or hips. The CSIA technique emphasizes inclining into the turn and counteracting with counter-flexion (or “rebound”) out of the turn. Rebound further increases the edge angle. It’s essential to avoid lateral skidding out of the turn, similar to traversing, because CSIA focuses on balance on edges, requiring strong control over the skis at all times. Skidding out of the turn is considered a loss of control. To make round turns and have your skis pointing all the way up the hill at the exit, increasing the edge angle upon exit is crucial, as this is when the most pressure control is needed.

Among these elements:
Angulation relates to body positioning and involves flexing all the inner lower-body joints.
Inclination relates to balance. Too much inclination can overload the inside foot, eventually leading to a fall.
Note that inclination is not a stiff sideways lean—the shoulders should remain parallel to the slope.

Another point is toppling, where you lean into the new turn during transition. This changes the direction of inclination and shifts your weight from one foot to the other.
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It’s somewhat like “falling toward the fall line,” but CSIA promotes a “square” position during transitions—meaning the whole body faces the direction of the skis without counter-rotation or active upper body movement. So I’d consider this more of a cross-under movement rather than a crossover.

Some teachings use the term Tipping, which often refers to engaging the edge primarily through the ankles.
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The following two fundamentals are more abstract and are generally integrated gradually through regular skiing. They also largely improve with accumulated ski time.。
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4. Timing and Coordination

This fundamental differs from the previous ones and is more related to the skier’s physical abilities. In terms of timing, for example, when skiing moguls or variable terrain, you need to quickly decide where to turn, how much, and in what manner. This requires anticipation. Coordination is similar—you need to quickly regain balance and recover from mistakes.
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A great example is pole planting. Skiers with less experience often struggle to truly feel the purpose of pole planting. Meanwhile, experienced skiers, even without formal training (excluding habitual patterns), can quickly pick up pole planting.

Mastering this will make your movements appear smooth, fluid, and graceful. Some say skiing is all about accumulated time on the slopes—and they’re right, especially when it comes to fundamentals 4 and 5, which rely heavily on ski time.

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5. Pressure Control

This is also a hallmark of North American teaching methods, which prefer to approach skiing from the perspective of “pressure.”

You can feel changes in pressure by skiing varied snow conditions and terrain—for instance, soft snow, hard snow, ice, or wet snow all feel different underfoot. Skiing on bumps or in deep powder is also a great way to develop this sense.
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The ski should remain in contact with the snow as much as possible throughout the turn, maintaining consistent pressure from start to finish. In contrast, braking-style traversing involves little to no pressure in the first half of the turn and then a sudden resistance in the second half. What we often call High-C (or high edge angle early) is actually engaging the edge early to build pressure early—a technique for speed control in carved turns.

People often mention “extension” and “flexion.” In reality, the combination of these two movements is a manifestation of pressure control.
--> Flexion – the center of mass (COM) accelerates downward, reducing pressure on the ski;
--> Extension – the center of mass (COM) accelerates upward, increasing pressure on the ski;
At slower speeds, we need to generate pressure; at faster speeds, we need to manage it.

Here’s a crucial point: when controlling pressure, you should feel as though you’re pushing your knees toward your chest—not pulling your chest down toward your knees. The former indicates proper flexion, while the latter is far less effective.
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That’s pretty much my current summary {hehe'''}, and I hope it helps everyone.

There are still many more details in the CSIA 5S technique that I haven’t yet learned, and my current understanding is relatively limited. I’ll continue to update with new insights as I learn more.