CSIA ---THE CANADIAN APPROACH

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Table of content

• THE CANADIAN APPROACH
• PHYSICS AND SKIING
• BIOMECHANICS AND SKIING
• TURN PHASES
• UNDERSTANDING SKIING
• SKILL DEVELOPMENT
  
  • STANCE AND BALANCE
  • TIMING AND COORDINATION
  • PIVOTING
  • EDGING
  • PRESSURE CONTROL
    
• TERMINOLOGY
  

INTRODUCTION


The Canadian technical approach to skiing is a result of the evolution of a sport. Equipment has
changed since the first skiers hit the slopes, but the laws of physics haven’t.

Many of the forms of balance and movements of contemporary skiing can be traced to
McCullough of the 50’s, Killy in the 60’s, Stenmark through the 70’s into the 80’s, and Tomba
through the 90’s to the “Herman-ator” and beyond. All of them showed the world the best way to
ski with the equipment of the day, and all of them balanced according to physics and
biomechanics.

Through competitive skiing and looking for easier ways to teach, instructors and coaches have
developed systematic approaches to analyzing and developing skiers. The sport of skiing can be
defined by technique, or science, but the development tools must be practical and effective.

The building blocks of the Canadian Approach are the result of the combined efforts of thousands
of people in 2 organizations who have worked with these ideas through ski schools or coaching.

The concepts presented here are the result of people sharing ideas on skiing, and looking for
better ways to do this.

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http://www.youtube.com/watch?v=l6f9serXLpM

In the skill development model, skiing is analyzed as a set of basic ingredients that exist in all
situations for all skier types. The blend of the skills determines the success of the skier in any
given situation. As a teaching and coaching tool, skill development is used to assess performance,
prioritize student needs, and develop strategies for improvement.

Stance and balance
Stance is the body alignment of the skier. A good stance is stable, yet mobile, and lets the skier
make balance adjustments.

Balance is the skier’s use of the neuromuscular system to keep from falling down. Optimal
balance uses the least amount of movement and muscular effort to align the COM and BOS,
supporting the skier and the forces of the turns. Stance and balance are the foundation for the
application of the other skills.

Timing and coordination
Timing is the skier’s ability to choose and use an action at the appropriate moment. Turn type,
terrain and snow conditions all affect a skier’s timing decisions.

Coordination is the skier’s ability to blend motor skills into a common movement. It is
determined largely by a skier’s natural athletic skills, physical experience and sport specific
training. Timing and coordination are grouped together, and also considered a foundation skill, as
they determine the successful application of other skills.

Pivoting
Pivoting is the ability to utilize the legs and feet to help guide the skis in a specific direction.
Whether the turns are carved or skidded, the lower body leads the turning effort.

Edging
Edging is the skier’s ability to use a combination of inclination and angulation to control the
angle of the skis against the snow and utilize their sidecut properties. Edging lets skiers control
direction and/or speed.

Pressure control
Pressure control is the skier’s ability to load and unload the skis at the appropriate time by
balancing against turning forces and/or using muscular efforts. It is closely tied to edging and
varies with the type of turn and terrain.

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STANCE AND BALANCE

Stance variations
When working with stance it is important to accommodate individual body types. The width of
hips or being naturally knock-kneed or bow-legged will affect the stance of individual skiers. Ski
boot choice and alignment also affect stance. The goal is to create the most mobile and natural
stance possible for any given skier.

Stance and stability
Width of stance varies with speed and snow conditions. Hard snow and higher speeds require the
stability that comes from a wider stance. Similarly, beginners will benefit from a broader base of
support. In softer snow, a narrower platform may be easier to control. In situations requiring
quickness such as bumps and broken snow a narrower stance may also be of benefit.

Balance as a dynamic process
Balance is not a static position but a continual series of adjustments to external stimuli. This is
especially true in skiing where the forces trying to throw the skier out of balance are strong and
varied. To “stay in balance”, the body reacts to the sensory feedback it receives from the inner
ear, visual cues and the sensation of pressure distribution under the feet. Muscular activity keeps
the skeleton upright and the COM over the BOS. Balance movements function in all directions:
fore-aft, side to side, up and down, and rotationally. Beginner and intermediate skiers tend to
“think out” their balance reactions, while advanced skiers and experts acquire automatic reactions
that involve only the muscles needed. Experts also anticipate possible imbalance, drawing on
experience to adjust to changes in snow and terrain in advance. This makes balance less reactive,
making the expert more precise and efficient.

Note: see Biomechanics and skiing: Stability, Maximum force and see Planes of balance.

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TIMING AND COORDINATION

Timing as decision making
Timing is the skiers’ interaction with their environment as they learn to interpret situations and
apply skills in the right blend and sequence. In any situation, the skier adjusts the timing of their
movements for the desired result. This aspect of skiing is developed through free skiing and
guided mileage.

Coordination of movements
Spatial awareness and motor skills are the tools for balance, and skiers coordinate their
movements to control their motion down the slope. Natural athletic ability determines much of a
skier’s coordination but it can be developed at any level. Developing muscular and sensory
response lets a skier react precisely and quickly. Warming up, varied skill progressions and
repetition of key movements will help develop coordination.

Timing and Coordination for development levels
At a beginner level timing and coordination means developing mobility, and rhythm through
serpentine turns. With more speed the challenge is changing both edges simultaneously, and
developing a range of movement for better edging and pressure control. With mileage the motor
responses are quicker and more instinctive and the task is refining the sensory skills and decision
making. At any level timing and coordination determines the successful application of the
other skills.

Note: see Biomechanics and skiing: Impulse, Direction, Angular momentum

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PIVOTING

Pivoting and direction change
With the upper body facing the direction of travel, turning the legs in the hip sockets creates a
steering angle. This, combined with ski sidecut, deflects the skier in their arc. Pivoting is seen in
the relationship between the upper and lower body.

Pivoting and balance
The ability to guide the skis on their path without relying on hip or upper body rotation will help
a skier maintain balance by keeping the body over the outside ski. From the hips down there is
less mass than in the torso, so changing direction with the lower body is quicker and lets the
COM move in a smoother trajectory.

Pivoting and edging
Upper/lower body separation enables a skier to balance on their edges through angulation.
Turning the femur in the hip socket allows the hip joint to be more mobile laterally to the inside
of the turn, helping to balance on the edges.

Pivoting and rotation
Turning the hips or the upper body before the legs at any part of the turn is called rotation. At the
top of the arc (phase 2) this could be caused by a rushed weight transfer (timing and pressure
control) or an imbalance from phase 1. Through the bottom of the arc (phase 3 into 1) it may be
caused by poor steering mechanics or a loss of control of angular momentum.

Note: See Biomechanics and skiing: Angular motion, Angular momentum and Planes of balance:
Rotational.

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EDGING

Edging and Direction Change
When there is a change of direction, edging is involved. Edging provides the grip that counters
the force of gravity and centrifugal force, keeping the skier turning. The degree of edging is
determined by how fast the skier is going when they turn, and whether they wish to de-
celerate, maintain speed or accelerate. Good edge control makes the ski grip but allows maximum
gliding for any given direction change.


Edging and Pressure Control
Turning on an edged ski or skis generates forces that give the skier a sensation of weight, or
pressure. When the skis are flattening (phase 1) they are releasing their grip and the load against
the snow diminishes. When the skis are turned across the line of travel (phase 2, 3) forces build
and the COM gets deflected. Edge angle increases and pressure builds. Bigger forces from higher
speeds and steeper terrain place greater loads on the skier which must be managed.

Inclination and angulation
Inclination refers to the line of lateral balance between the BOS and COM. This degree of lean is
what the skier must do to counteract the forces of the turn, and it changes within each turn in
response to speed, external forces and intended path of travel. Too much lean and the skier stands
on the inside ski or falls over, and not enough makes it impossible to maintain the arc of the turn.

Angulation is the bending of body segments as the skier inclines. Controlled by the use of ankles,
knees and hips, it keeps the skier in balance against the edges and lets the skier produce edge
angles that are greater than what can be achieved with inclination alone.

Turn Initiation – changing the line of inclination
While balanced on an arc, the COM is inclined to the inside of the BOS. To change direction, the
skier must change this line of inclination, putting the COM to the inside of the new arc. A wedge
or stem is a way of placing the BOS to the outside of the new turn, changing the line of
inclination to the new side.

In parallel skiing this “toppling” can be achieved by releasing pressure on the outside ski and/or
transferring it to the other ski. This effectively shifts the BOS from the downhill ski towards the
outside of the new arc, changing the line of inclination. A smooth release in phase 1 is also a way
of getting the COM to the inside of the new arc. Most edge changes involve combinations of
these elements, and can be passive or active, simultaneous (parallel) or sequential (wedge),
depending on the skills and desires of the skier.

Note: See Biomechanics and skiing: Stability, Direction,Impulse,  Angular motion, Angular momentum, as well as Planes of balance: lateral.

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PRESSURE CONTROL

Pressure control – the sensory skill
Alternating between weightless acceleration and the heaviness of turning and resisting gravity is
part of the allure of skiing. The dynamics of turning creates loads that the skier manages through
good biomechanics and balance, giving the sensation of pressure and gliding. Terrain and snow
conditions also contribute resistance and acceleration. It is this range of possibilities that skiers
learn to anticipate and react to.

Controlling snow contact (“up and down”)
Movements of flexion (bending the body) and extension (lengthening) act as a suspension
system, and keep the COM on a stable path and the skis in contact with the snow. These “up and
down” movements happen on the line of inclination, or perpendicular to the edge angle of the
skis. The moment of maximum inclination is often when the body is longest, even though the
COM is closest to the snow. When the COM naturally rises as the line of inclination changes
between turns, the skier bends to control the amount of rising. As ski reaction and/or terrain
difficulties increase these effects are amplified.

Fore/aft pressure
Fore-aft mobility takes advantage of ski design and lets the skier adjust quickly to terrain
changes. Today’s skis are designed to be turned from the middle of the sidecut, but the front of
the ski must be in contact with the snow for it to help initiate the arc (phase 2).If pressure is too
far forward the COM will start to take over (rotation). When the amount of resistance the skier
encounters increases due to direction change or snow resistance, the feet will appear to be further
ahead relative to the COM. Adjustments can be made by moving the BOS, the COM, or both.

“Weight” Transfer
Contemporary skiing is more two-footed than ever. Skis are designed so that both contribute to
the turning effort. The turn starts with weight more equally distributed on both skis (phase 1). As
turning forces build (phase 2, 3), the load shifts naturally to the outside ski. Between arcs as the
COM crosses over the path of the BOS, the skis are flattening and the load shifts back to both
feet on its way toward the new turning ski. This sensation of ‘weight’ or pressure transferring
from ski to ski is generally gradual and is timed to cause minimal disruption to the path of the
COM and the gliding of the skis.

Note: See Biomechanics and skiing: Impulse and Direction, and Planes of balance: Vertical,
Lateral, and Fore-aft.

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The 4 planes of balance define the relationship between a skier’s base of support and centre of
mass as they move in curved trajectories down the mountainside. Instructors can use these planes
as a way of assessing balance and responding with targeted skill development.

The lateral plane
The lateral plane is the ability to adjust width of stance and body movement to balance in a sideto-
side manner. It refers to adjustments in width of stance, the blend of inclination and
angulation, and the way the skier changes edges between turns. Balancing on the lateral plane is
the way skiers greet forces that are generated in a turn (related skills: edging, pressure control,
stance, timing).
The fore-aft plane
The fore-aft plane defines the skier’s ability to maintain alignment with the feet and COM in a
forward/backward plane. Maintaining balance on the centre of the side-cut requires adjustments
to compensate for speed, resistance, and terrain changes. An example of poor fore-aft balance are
skiers that get “caught back” as the skis are tipped from across the hill towards the fall line.
Another is over-flexed ankles, causing the COM to be ahead of the feet. Good fore-aft balance
requires a mobile stance and anticipation of terrain and snow (related skills: stance and balance,
edging, pressure control).
The rotational plane
The rotational plane describes the control and adjustment of rotational movements between and
within the upper and lower body segments. Initiating a turn by twisting the hips or upper body is
a common example of imbalance in the rotational plane. Similarly, a skier who faces too much to
the outside of the turn is not balancing efficiently. Natural alignment in the rotational plane has
the skier facing their line of travel. This is a tangent to the arc of the centre of mass at any given
time. Good balance on the rotational plane is created largely by a relaxed stance and allowing ski
side-cut to lead the turning effort (related skills: pivoting, timing, edging).
The vertical plane
The vertical plane is the skier’s ability to adjust up and down movements relative to the edge
angle of the skis. Regardless of the degree of lean (inclination), skiers bend and extend their legs
to control snow contact and steering load. The patterns of these movements vary with the
situation and desired outcome. An example is the bending between turns necessary at higher
speeds to maintain snow contact. However if an abrupt un-weighting of the skis is desired in
heavy snow or steep terrain an extension through the same part of the turn could be more
effective (related skills: pressure control, timing and coordination).

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http://www.youtube.com/watch?v=Lfb_xV2BExk
Turn Phases are a way of linking a skier’s movement patterns with specific parts of the turn.
They provide a template for skill assessment and development by prioritizing and sequencing
skills.
Turn Phases as a working tool
Although sequenced from 1 to 3 for reference, turn phases can be approached in any way that is
effective for results. For example, working the timing of edging in phase 3 could be a way of
developing stance in phase 1. While turn phases provide an excellent way to break down turns,
skill development should always lead to linked, fluid skiing.
Phase 1: Completion to “neutral”

http://www.youtube.com/watch?v=D6ziBbtCX70
The skier must be balanced to manage pressure and forces generated by the turn.
The COM is released from its arc, diminishing the line of inclination. This takes the skier to flat
ski(s) between turns, and lets the COM travel freely down the hill and towards the inside of the
next turn.
The COM and the BOS come out of the turn together, with the skier in a balanced, neutral stance.
As the skis flatten, they are released from their arc, diminishing the steering angle.
Phase 2: “neutral” to fall-line

http://www.youtube.com/watch?v=fvLE2irPpog
A new turning platform is established. In parallel turns, the skier should feel the side cut of
both skis.
COM maintains its momentum, moving forward and inside the arc.
The skier stays centred in anticipation of the loading that will occur later in the turn. Steering
with the lower body creates a natural upper and lower body separation.
Phase 3: Fall-line to completion

http://www.youtube.com/watch?v=8SThrlh4eKE
The skier progressively increases edge angles through angulation. As the turn radius tightens,
steering angle increases.
To manage the external forces, parallel skis as well as legs and upper body stability are crucial.
The steering and loading is timed for direction change and/or speed control and helps to create
linking back into phase 1.
Adjusting Phases to different types of skiing
Turn phases apply to wedge turns also:
1. With equal weight on both skis, a beginner will glide between turns.
2. The turning platform is established as the skier creates balance over the outside ski
through separation and subtle angulation.
3. Edge increase is subtle, but grip with the outside ski creates deflection.
In steeps and bumps the timing of the phases change:
1. The edge release happens quickly and is often initiated with a hop or release of pressure.
2. Upper/lower body separation results from an active pivoting of the legs beneath the skier.
3. Steering is active, and helped by terrain contours. Edging later in the turn controls speed.

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Biomechanics is the application of mechanical and physical principles to body movements. It can
help explain efficient movement patterns for any sport or activity.
The 7 Biomechanical Principles have been developed by the NCCP (National Coaching
Certification Program). Instructors and coaches with a good understanding of these principles can
make better skill assessment and development decisions. The 7 principles also provide a tool to
evaluate technical trends in skiing in terms of function, not fashion.
1. Stability
Stability is increased by lowering the centre of gravity and/or widening the base of support.
Conversely a narrower stance is less stable, but can facilitate agility and quickness. This explains
why a low, wide stance is preferable for a beginner or for a racer at high speeds on an icy surface,
while an expert in bumps or soft snow may choose a taller, narrow stance.
2. Maximum force
To produce or resist maximum force, as many joints as possible must be involved. Also closely
related to stance, this principle is due to the mechanical advantage created by all the joints and
muscles working together.
3. Velocity
Producing maximum velocity requires the use of all available joints in order of largest to
smallest. This is easily seen in throwing sports. In skiing the feet are in contact with the snow, so
the sequence is less apparent and practically simultaneous. A skier needs to use the ankle, knee
and hip joints together, but the big joint (the hip) must be inside the turn for the other joints to
work effectively.
4. Impulse
Impulse is force multiplied by time, and increasing impulse increases velocity. Impulse is the
skier’s work energy added to the forces of the turn. Some of this energy will become potential
energy stored in the ski and boot that will provide kinetic energy when it is released. Impulse can
add life and rebound into skiing, but applying too much, or at the wrong time can disrupt the
glide of the ski.
5. Direction
Movement occurs in the direction opposite to the applied force. For example, a skier wishing to
accelerate can apply force at the top of the arc to contribute to direction down the hill. Similarly,
a skier wishing more direction across the hill will apply their force mid-way through the arc, and
a skier wishing to control speed will apply force at the end of the turn, effectively providing some
direction back up the hill.
6. Angular motion
Angular motion is produced by the application of force acting at some distance from an axis
(torque). In skiing, the skis act as lever arms creating torques on the body. Upper and lower body
separation is a way of resisting the torques so the skier can stay balanced. Less effort is required
to resist twisting forces if the hands are held wide. By spreading the mass of the arms out, the
skier is rotationally stabilized.
7. Angular momentum
Angular momentum is constant when an athlete or object is free in the air, and conserved when
grounded. The “spinning” forces involved in turning have momentum. If a skier is “spinning” on
ground and loses contact with the snow, the spinning will continue. Conversely the skier can
store energy like a twisting spring to manage carving and create turn linking. Stopping this
momentum with a pole plant lets the legs redirect between turns independently of the upper body.