The Skills Framework
In the same way the collaborative teaching approach outlines the framework for the teaching model, the skills framework is the blueprint for assessing and developing skiers. In its simplest version, the framework defines WHAT you want to have happen, HOW the ski must move to make that happen, and HOW the body must move to make the ski do it. There are three skills: Rotational control, edging control and pressure control. The appropriate blending of these three skills allows us to travel down the mountain as we desire. These three skills describe the options we have over the skis and our movements to dictate how our skis interact with the snow.
Rotational Control
Rotational control refers to a twisting action of the skis around a vertical axis. In effect, the direction the skis point by applying a twisting or turning action to the ski.
The steering angle is the angle created between the direction of travel and the direction the skis are pointing. By adjusting the steering angle, we can manipulate turning forces and, as a result, our direction. The steering angle also affects the slowing component. Varying steering angle alters the proportion of turning and slowing components; this allows us to control our direction and speed down the hill. In most cases, a steering angle is created by applying a twisting effort to the skis, but it can also be created by ski design, as a ski bends along its length.
The rotational effort of the body or specific body parts produces a rotational effort to the skis. There are several ways the body can move to produce this rotational effort, some more effective than others.
Leg rotation- internal and external femur rotation inside the hip socket. By turning using the lower body, we’re more effective at directing the skis and are more efficient than turning using the upper body. The lower body can manipulate the rate and intensity of the rotational effort quickly and more effectively than the upper body.
Hip and upper body rotation- Upper body and hip rotation initiates a twisting action of the legs, subsequently producing a skis rotation. Compared to the lower body turning, this method is less efficient and will compromise balance as the centre of mass is disturbed by the rotation of the upper body. Turning with the lower body allows the centre of mass to remain stable. However, in situational skiing environments, such as steeps, powder or crud, it can be an effective method to help produce the required rotation of the skis.
Counter rotation- This occurs when the upper and lower body turn in different directions at the same time. Although not encouraged, it can be a handy tactic in certain situations. This counter produces a very quick turning effort to the skis and creates a significant steering angle. You’ll see this often in ski racing when a skier uses a counter to rapidly change a ski’s direction to make the next gate.
Edging Control
Edging control is the action of the ski tipping or tilting along its length. By adjusting the amount the ski tips on the snow, we can control how much a ski grips, slips and bends along its length. We can change the edge angle by lateral movements of the body across the skis.
By manipulating the edge angle, we can control whether a ski slips or grips and how much drifting is present. Drifting is the blend of the ski side slipping and travelling forward simultaneously. The ski tails slip and displace further and faster than the ski tips, producing a wider track in the snow. Increasing edge angle reduces the side slipping component of a drifted turn. Eventually, the side slipping is removed entirely as the tail of the ski grips equal to the tip of the ski; we then produce a carved turn, where there is no drift, and the tail of the ski follows the tip of the ski exactly, leaving a clean pencil line track in the snow.
Whenever we turn, our centre of mass (generally located around our hips) will continue to travel further inside the path of our skis. Edging movements are any parts of the body that control how far we move laterally inside our skis. Like rotational control movements, some body parts are more effective and efficient at manipulating the ski’s angle on the snow.
The ankle-Controlling ankle movement and tension shifts pressure to the inside and outside of our foot, changing the skis edge angle. This pronation and supination of the foot and ankle is the quickest and most effective way to manipulate edge angle. There is a limit to how far the ski can be tipped using just the ankle, so other parts of the body are involved in edging movements.
Knee- Even though the knee appears to be involved in edging, there is only a small amount of lateral movement. Knee movement is generally a result of internal leg rotation and ankle movement. The knee is used a little more in short turns due to the lack of hip movement. However, too much lateral movement of the knee weakens our stance.
Hip-A lateral movement of the hip towards the inside of the turn, combined with some separation of the upper and lower body, allows the COM to travel further inside and the edge angle to increase, all whilst maintaining balance on the outside ski. Angulation at the hip joint will enable us to build a greater edge angle than inclination alone. Hip angulation is commonly used in longer turns when pressure is highest, as the speed at which edge angle can be changed is slower.
Pressure Control
Pressure control describes the skier’s ability to manage balance side to side, fore-aft and vertically. Moving well in these three planes enables us to manage forces effectively and travel smoothly down the hill.
During every turn, our balance forwards and backwards along the length of the ski is constantly challenged. This results from changing slope gradients and terrain changes such as bumps. We can alter the skis’ self-steering effect by manipulating our balance forwards and backwards. More or less of this function has its purpose depending on what you want to have happen. Pressure further forward at the start of a turn allows for better balance and turn initiation; pressure further back allows for more grip along the whole length of the ski at the end of the turn. By adjusting our balance forwards and backwards, we aim to maintain optimal balance between our base of support and our centre of mass.
As it is advantageous to ski on the outside ski, we must transfer our weight from ski to ski between each turn. Lateral movement of the body and flexion/extension of the ankle, knee and hip allow our COM to be shifted so that the outside ski predominantly supports it. Managing this weight transfer effectively maximises grip and puts us in a stronger position to deal with turning forces as we’re biomechanically stronger through the outside leg.
Managed through flexion and extension of the ankle, knee and hip, vertical pressure control manages the amount of pressure through the base of the skis, allowing for a more stable COM. Think of this like the suspension of a car. The better the suspension system, the more comfortable the ride is for the driver. Managing pressure vertically also allows the skier to maintain ski-to-snow contact, most apparent in bumps or at the expert level when forces are much more significant.