Over the years, I have been trying to increase my speed (down the hill) and performance in all high end turns. Both of these aspects inherently increase risk and the pressure given back from the snow pushing on the base of the ski. To successfully improve both of these, I felt that I had to look more closely at the physics involved with skiing rather than the individual skills or movements. Essentially skiing is a balancing, or aligning the Centre of Mass (CoM), Base of Support (BoS) and Centripetal force when it is at its greatest. Thinking more about this and less about specific movements has helped me a lot.
When starting in the ski industry, I had (and think that a lot of others have) a strong misconception about the importance of inclination. From instructor level 1 we are taught to angulate and the need for angulation is heavily stressed. All of us are aware that angulation requires inclination, but I feel that in this statement the angulation is the emphasis and inclination is merely a movement to facilitate angulation. This is a major misconception and leads to a lot of Basic Position issues further down the track at L3 and L4.
To achieve the above mentioned goals (speed and performance) angulation has not been the goal for me, tipping the skis on the edge and being able to deal with the pressure has been the goal. This is only possible if something moves to the inside of the turn. Now the interesting thing is that after talking to candidates, and remembering back to what I believed when I was training, the common thought is that inclination is bad for all sorts of reasons. The common thought is that if something moves in then something up top must move out otherwise I'll be on the inside ski. My mindset has now changed to: “appropriate inclination for the speed is what causes our skis to increase edge angle and align the the CoM against centripetal force”!
So I guess firstly it needs to be established very simply why we incline and why we angulate and the simple physics behind it. Please see “Diagram 1” on the image below: on the left side the skier is standing up straight and the skis are flat. On the right the skier has moved to the inside which has caused the skis to increase edge angle which results in centripetal force pushing against the base of the ski.
So we can see very simply from this diagram that it is inclination that improves performance here and not angulation. So where and why is angulation so important? To me it is simply a tool to balance efficiently against the centripetal force pushing against the base of our skis. Looking at “Diagram 1” again, you will see that the inclined skier's CoM is not balanced or aligned against the centripetal force pushing against the the base of either ski. To deal with any force efficiently, our CoM needs to directly oppose centripetal force so that it is a balanced force. In other words our BoS (or foot) needs to be directly in between the 2. In the above diagram the skiers CoM does not directly oppose the force pushing on either ski (as can be seen by the dotted blue lines).
As the pressure starts to build through the turn, we must all decide which leg will be our primary BoS so that we can align our CoM directly opposing centripetal force and balance the equation. As we are all aware, the longer, outside leg is a in a much stronger position than the inside short leg. So the outside would be the best and safest option. This is where angulation comes in. The stickman's CoM would not have to move far to the outside to align itself with the pressure pushing on the outside ski. In real life terms we are talking 10-20cm at most. Please see “Diagram 2”, the skier on the right has only slightly angulated causing the CoM to shift ever so slightly to the outside now balancing the centripetal force pushing against the outside ski.
The point I am really making here is that the amount of angulation needed is very small if the skier has inclined the appropriate amount relative to their speed and the pitch of the hill. The spine is not vertical, it is still inclined. Anymore angle than this and the skier would be over angulated creating as many, and potentially more sever problems than being too inclined.
The position in “Diagram 3” is very common among high level skiers and
particularly candidates around level 3/4. This “over-angulation” is just as
unbalanced and possibly more dangerous than if the skier were to incline or
completely bank into the turn as in the first diagram. The ski is over edged and
the centripetal force has to go somewhere as it is not opposed or balanced. This
usually results in over straining of the leg muscles to deal with the pressure and
failing that, the skis jetting out in front of the skier. Over angulation often feels
like there is too much pressure or increased “g-force” through the turn. It can
feel like leg muscles are struggling and your whole body is getting smaller. This
struggle is not only uncomfortable, it also prevents the skier from moving further
inside further and increase in edge angle and centripetal pressure. At slow
speeds this position can be dealt with through muscular effort. The interesting
thing is that most people would say that this is a good position.
“Diagram 4” shows the average traverse position (demo at L1) on the right versus an angulated position during a high speed, purely carved turn on the left.
I feel that the amount of angulation in the traverse position on the right is appropriate for all turns as this position is aligning the CoM, BoS and Normal force from the ground (which would be centripetal force during a turn). For the skier to increase performance from this position they would need to simply incline the whole position as the speed increases and nothing more (as the diagram shows on the left). I think the mindset among most of our candidates and the skiing population is that as the position inclines, it also needs to angulate more.
A lot of people may say that the image on the left is not angulated enough and is pure inclination or “banking” in comparison to the image on the right. However, the only difference is the inside leg. On the left the inside leg has relaxed and shortened to allow the whole position to topple in. The skis are now on a lot more edge and the CoM looks roughly balanced over the outside leg against where the centripetal force would be pushing at the right speed.
Now looking at “Diagram 5”, it is interesting to see that the stickmen are drawn from a photo I had taken last season. Both are the same, one has just been rotated to show that in fact it is the exact same amount of angulation in a Pure Carved Medium as in the traverse position it is just more inclined.
So as you can see from the this, the angulated position that almost all intermediate to advanced skiers (and L1 candidates) can perform is a good position for them to ski into even at higher speeds. This position is simply skied into by relaxing the inside leg as the speed increases. So the mindset amongst high end skiers and instructor candidates should maybe change so that inclination is not looked down upon (providing you are still on your outside ski).
While it may sound a little like I am supporting the lean and hope technique, I am not. Angulation is the key to successfully inclining and staying in balance. Without the appropriate amount of angulation we will fall to the inside and lose grip with the outside ski.
After attending the Korean and Japanese workshops at Interski I started to play around with a few different ideas. They heavily stress weight on the inside ski or 50-50 ski weighting until the fall line to aid inclination. They believe that moving in with angulation and weight on the outside ski limits the amount one can move in. The important part for them is being inclined enough to deal with the extreme centripetal force at, or just after the fall line when the pressure is at its greatest. So I started playing around with inside ski weighting until the fall line. I found a lot of the time the outside ski railed due to lack of pressure and I fell to the inside. But if I was going fast enough (really fast) there is enough pressure to be inside that far and still aligned against the outside ski. The turning becomes extremely smooth. One can build more pressure due to the extreme edge angle of the outside ski and there is no struggle to be felt. That feeling of “g-force”, pressure, strength and struggle as felt in the over-angulated position was not there. It feels simple and easy because the forces are aligned and the skeletal system is doing its job.
I started looking at slopes as soon in “Diagram 6”. In Diagram 6, the arrows signify roughly where the pressure will be at its greatest. This means that I need to
be in a strongly inclined position (with appropriate angulation) at these points
and what happens in between is not so important as the pressure I am
dealing with is negligible or aligned with the direction my CoM is travelling.
This allowed me to get my head around inside ski weighting before the fall
line as being ok and not a cardinal sin. This helped me incline a lot. Now a
lot may say that inside weighting is very bad, but after looking through many
photo sequences of world cup racers I have found that in some cases, a racer
may enter a turn with the inside ski off the ground and in other cases the very
same racer may enter a turn with outside ski off the ground. The position on
the gate where the pressure is at its greatest is identical between the 2. This
means that inside/outside weighting through the initiation is not so crucial as
long as one can incline enough to deal with the pressure when its at its greatest.
So how can we change this mindset that inclination is bad and angulation is the only way? Firstly by playing around with inclination in our own skiing. This has helped me a lot. I have been Inclining as much as possible at different speeds to see how far I can move in. Eurocarving, hand drags, outriggers, Japanese hybrid turns, hybrid snowplough turns and white pass turns are all good exercises to experiment with. I encourage everyone to get out there and have a go. Remember though that moving in this far is only needed at very fast speeds or on very steep slopes so this technique will only leave you on the inside if done down flatter terrain or at slow speeds. Appropriate inclination for the speed and gradient, with the correct amount of angulation is the key. This needs to be understood by all of our higher level skiers and instructor training candidates. I hope this has explained a little about what I have been thinking about in skiing at the moment.