Thursday, April 10, 2014

Jim, Adrienne, Luke, David, Chloe

The last time I had seen Jim and Adrienne was at least 20 years ago in Aberdeen – long before Luke, Davis and Chloe were born. I was amazed to see that they hadn’t changed. There wasn’t a lot of time for reminiscing though because we were here to ski. I intended to pass on as much information as possible in the course of the day and as everyone seemed hungry for improvement the social side of things would just have to be squeezed in along the way. I don’t think anyone realised what they were in for regarding instruction! Jim had suggested that I give perhaps a few tips! With the level of receptivity being high in the family group I just pressed on with teaching.

Warm Up

During the warm up run I took a moment to look at everyone skiing. David was a strong skier who had a lot of natural dynamics but also some serious quirks to be straightened out. Chloe also had some good natural dynamics in her skiing  - probably from snowboarding. Luke, who represented Britain in skiing in the 2013 Special Olympics World Winter Games was a confident skier. Adrienne was relatively stiff, rotating and unstable and Jim tended to rush the start of his turns displacing the skis more than the body. All the issues here were typical products of classic ski instruction. My goal at this point was just to observe and then make a decision on a common denominator as a starting point to begin making changes for the entire group.

Dynamics

The starting point was Dynamics. I used my normal set of static and moving exercises described in detail here on the fixed page: “Dynamics page

Everyone responded well to the movement with the “non snowboarders” feeling the greatest difference. Luke’s first attempts were more accurate and successful than anyone else’s.

During a drinks break I explained the origin of the the “Dynamic Balance”  confusion stemming from Jean Le Rond d’Alembert and his mathematical substitution of fictitious forces for accelerations. Dynamic Balance is a fiction and amounts only to being a mathematical tool not a physical reality. 

The goal at this stage was to build awareness of the motion of the centre of mass – and use of the active centre of mass to drive the skis.  I explained that the skier has one job and the skis have one job. The skier has to fall over (laterally) and the ski has to bring the skier back up. The skis are far more powerful than the skier so there is no chance of falling.

After some practice at this we tried to extend the dynamic range. Each skier watched all the others ski to see how far over they could fall. Most people are lucky if they can manage 25° to 30°

When skiing it is important that the centre of mass is driven inwards even harder during second part of the turn where we work against gravity and the mountain geometry. There is greater edge angle as the turn progresses and the lifting up power of the ski grows during the turn – so it is important to be aware of this and to drive everything inwards until the moment the turn needs to be given up. The giving up of the turn is called “Turn Exit Dynamics” and we will look at that towards the end of the blog. Jim and Luke missed this at the end of the day when it was used to help David skiing in the slush.

We used a small border cross run to exploit the banked tracks to help encourage dynamics. I explained that the skis and boots together actually give us banked tracks all the time and that we need to perceive this in 3D and not as a 2D flat surface with turning. Skiing is more akin to a “velodrome” type exercise.

Skating

First of all I checked that everyone could skate. There were no problems there. Normally I would go through quite a few skating exercises and build things up progressively but there was not time for that today. Once I could see that everyone could skate we went straight for the “direct method” starting with skating straight downhill. Once some speed builds up then the body can be allowed to fall over further to the inside on each skating stride. Adding dynamics (falling over) to the skating like this converts the skating into skiing. Most people however struggle to maintain the skating stance, leg action and timing initially. This sort of development requires practice.

 

Most importantly everyone could feel the timing and use of the legs and nobody had experienced this before – despite it being the basic timing required for skiing. The skating action of the legs  is a “down/up” action and this matches the down/up action of dynamics. (Think of a motorbike turning – it goes down into a turn and comes back up out of it.) The aim at this stage is to tune into a resonance with the skis and to feel the power of this. The legs should begin to become functional instead of static and just bracing against forces. This timing is natural for the human body and the pressure cycle created is what allows grip on ice. Skis have been designed to work with this pressure cycle since around 1970 – though ski schools still teach the exact opposite.

Skiing with dynamics and observing the pressure changes happening beneath the feet there is a sensation of skating imparted to the body – even when not trying to skate.

Getting the basic timing right is a primary goal at this stage but later on this timing is developed further with many variations to accommodate terrain and function (accelerating or slowing down etc.)

As a rule everything is skiing is either dynamics or skating.

Carving

Over on the Grand Pré flats it was the opportunity to take a look at carving. Carving is useful to develop at this stage because it requires pure dynamics. The first stage was to introduce the rolling of the feet from the subtaler joints below the ankles. This also meant introducing the idea of standing on the heels. I indicated that the rolling of the feet uphill – onto their uphill edges – also moved the centre of mass uphill. We all tried a traverse across the hill leaving two “railed” tracks in a wide stance.  From this we moved on to “edge changing” by using poles for support and moving the body across the skis to change edges – from uphill to downhill edges. Once this was accomplished it was time to try it while moving forwards on a very shallow gradient and avoiding turning too much across the hill.  Jim in particular had skis skidding throughout the turns instead of carving – but was unaware of how the difference should feel with the skis completely locked.

We did one exercise with the outside ski extended out like an outrigger and pulling against it – even turning the upper body inwards during the turn and weighting the inside ski which was acting as a stabiliser. The idea was to stop Jim from pushing outwards on his turning ski until he could feel it driving him inwards instead and feel his ability to hold everything towards the inside of the turn. 

Blasting down the rest of the slope to the lift everyone had the chance to try carving at speed on a wide slope of moderate gradient. Higher speed requires greater dynamics. The feedback from carving is very clear as the ski is locked on and the force is very strong. The only way this can function is with pure dynamics – motion of the centre of mass across the skis.

Slalom (Best times - David 26.16, Chloe 30.86, Jim 32.78, Luke 35.40, Adrienne 36.11)

Having worked on dynamics, skating and carving it was a good time to bring in the slalom. We ran through the etiquette of how to correctly make use of the slalom stade and we sideslipped the course to remove the worst of the ruts and banks of slush. My only advice was to use dynamics with the gates being an indication of the direction to move the body – and for David to use a wider stance . David in particular was moulded by the slalom course into something resembling a real skier! He couldn’t exploit his usual shoulder rotation and subsequent counter rotation to push the heels out – with hips locked up in a stance leaning backwards.

Feet

Indoors after lunch we went through the basics of how to work properly with the feet and ski boots. Standing on the heels the subtaler joints can be used to rock the feet onto their edges. We had done this earlier when carving but now with the boots off it was visible. Bending at the knees and hips when on the heels causes the shins to tighten (anterior tibialis) and ankles to strengthen up. There should only be a light contact with the front of a ski boot and the ability to bounce off the front. Support is from the legs not the boots. Flexing in this manner when on a hillside or turning does not cause a falling backwards – though it may do so when standing still on the flat inside a café. The foot rocked onto its inside edge should solicit the adductor muscles of that leg and this should be linked to the centre of mass moving inwards also. Everything pulls inwards!

Chloe had to avoid her tendency to stand on the front of her foot and collapse her ankle, twisting the knee inwards. The correct lateral movement inwards of a knee is very limited and best achieved from the support of a strong ankle when standing on the heel. Adrienne had to pull her hip backwards when initiating a turn to keep her femur in line – and also to prevent her tendency to do the opposite and let her hip lead the turn. This hip action comes from ChiRunning – referenced here on the fixed page “ChiSkiing”.

Foot Forwards

To assist in coping with steeper terrain I  introduced “ foot forward” technique. The exercise used was with the skis off and one leg being swung around to the outside in an arc, with the leg rotating in the hip joint. This is also a good way to practice the active pulling back of the hip to prevent hip rotation. The arc is then lowered to make contact with the snow and eventually pressure is applied to the ground to give resistance. The feeling given here is exactly the right feeling for applying to skiing. I didn’t say what was going to happen but just asked everyone to put their skis back on and try pushing the foot forwards during turns.

Everyone noticed the turns being tightened.  This is a key mechanism for controlling turn radius. Dynamics and “foot forward” technique combined are how to determine turn radius.

Pivoting

There is a dedicated fixed page on pivoting: “Pivot Page”. I had already briefly shown how the pivot starts from the outside edge of the uphill ski. David had spotted that there was a difference in how I was using my edges – but couldn’t see the positive side of it. He thought I just “used my edges” towards the end of the turn. I was actively using the “other” edges in fact – as brakes.

While the stance being wide helps with edge changing for dynamics – to be able to stay on the uphill edge for the first half of a turn necessitates having the skis close together. (There are ways of pivoting with feet apart though!)

The key to pivoting however is to allow the uphill ski to remain on the outside edge while the foot rolls onto its inside edge inside the ski boot. This permits an active use of the adductor muscles for pulling the tips of the skis inwards as the centre of mass moves off downhill (supported and restrained by a pole plant downhill). Once again everything pulls inwards. I assisted Luke through a complete pivot so that he would have the opportunity to feel it correctly.

The point is that in skiing it doesn’t really matter much of the time with edge is used to initiate a turn! The centre of mass drives the turn! Fall line skiing in a braking manner on steep terrain requires a pivot – so it is used by mogul skiers and in deep powder. It is also used for jump turns and short swings in couloirs.

David had a strong tendency to push his skis outwards instead – resorting to his mixed up “shoulder rotation followed by counter rotation” error.  I explained to David that centrifugal force is an illusion and it doesn’t exist. There is nothing to brace or push out against in skiing. The only forces generated are by the skis pushing us inwards away from a straight line and so we must move inwards to help this and not push outwards. Using the analogy of a ball on a string being swung around my head the answers I received as to the direction it would travel when released were very interesting. Chloe said straight ahead, David indicated a tangent and Luke brilliantly suggested straight upwards! David was of course correct, but Luke’s originality stole the prize.

Turn Exit Dynamics

Jim missed this section but it is covered on the fixed dynamics page. I wanted to help David cope better in the slush by eliminating his rotation issues. Working on the turn completion can help with this issue. The goal is to use the power of the downhill ski to lift yourself right out of the turn over to the perpendicular to the mountain. Until this point I hadn’t mentioned the end of the turns and how to get out of the turns to link up the following turns.  It’s quite scary at first moving all the way out of a turn while on the lower ski – because the body actually goes beyond the vertical over to the perpendicular to the slope – while crossing the slope – which is only sustainable for a fraction of a second. This however makes the start of the next turn incredibly easy and removes the need for any rotational tricks.

Chi Skiing

I explained to  Jim and Adrienne the basis of ChiRunning (Danny Dryer) and how I adapted it to cycling and skiing. The fixed page is here – including an outline of the book: “Chi Skiing”. This is why I mentioned several times to pull the hip backwards (supporting leg). Skiing pulls this hip forwards and causes a postural collapse so the hip needs to be pulled actively backwards to protect the body as well as to improve technique and performance.

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