Thursday, March 31, 2016

Robert 5

The warm foehn wind was too strong and rapidly brought most of our chosen sector of Le Fornet to a close. Winds were forecast at altitude but it did look much clearer in that direction – and the snow would have been good on the glacier. The Solaise express eventually closed too so the only sector probably left functioning was La Daille – which should be sheltered from the southerly winds. Clear sky during the night had allowed heat radiation from the snow to cause it to freeze despite the high air temperatures.
  

Our group for this morning was mixed – with Winfred aged 8 and Elspeth aged 11 along with Robert, Clea, Mary and Richard. Despite the varied group, wind and limited pistes we made the most of the opportunity to work on technique. Winfred was very patient through the explanations and exercises because the delivery of the lesson was not targeted at his age group.

Chi Skiing 

Having watched people all week skiing without their core muscles activated correctly and witnessing the consequences it seemed like this would be a good opportunity to tackle this subject. It wasn’t tackled previously because there are many issues which affect the capacity to ski far more – though overall this is probably more important than any of the other technical issues.

Facing the shoulders downhill as a turn progresses has the consequence of twisting the lumbar spine slightly from the top down as the skis come around the turn. The outer hip ends up beneath the front ribs and postural reflexes just cease to function.

Facing the pelvis downhill – but preventing the shoulders from doing so causes a twist of the lumbar spine from the bottom up in a counter direction to the turn  - causing a slight stretch between the outside hip and the bottom front rib. When loaded up with pressure this configuration allows the core postural muscles to work by reflex. Not only does this protect the lower back but it has huge effects on technical development and skiing performance.

Each person in turn was guided through a “load testing” exercise where first the shoulders were turned downhill and then the pelvis – standing still across the slope with a ski pole held across the front of the body. I supplied the load/resistance as they tried to lift me up while I put my weight on the pole. With the shoulders facing downhill everyone could feel the load on the back and nothing in the abdomen – and then with the pelvis facing downhill everyone felt the abdomen contract and no sensation of load on the back. This happens because the alignment allows reflexes to work and the abdomen creates a “hydraulic sac” where the load is spread across the whole midsection. Normally this is hydraulic sac is achieved through “neutral pelvis” by pelvic tilt  (tilting the pelvis up at the front) – but what this exercise shows is that there is a separate way to ensure that protective reflexes work. In fact, pelvic tilt alone does not protect a skier because the shoulders coming around makes pelvic tilt ineffective.

The pelvis has to move in this manner during the turn transition – so that it is set up from the start of each new turn. Turn initiation is also rendered far easier and more effective when this is done.

The core muscles correspond very closely to centre of the body and this is where movement should commence – both overall for the motion of the centre of mass and internally for biomechanics. Pulling the hip backwards pulls the femur into alignment with the adductor muscles and helps to roll of foot onto its inside edge inside the ski boot.

Now you can see why I was Impressed that Winfred listened to all of this!

Mary can make use of this core action to work on preventing rotation. Clea tends not to stand strongly on her right hip so this would help to straighten out that issue. Using the new hip position to flex more at the hip joints – and correspondingly at the knees – would free up Clea’s skiing enorlously.  Robert is vulnerable to the upper body lurching forwards in tricky off piste or bumps so the strong core would stop that and protect his back. Richard needs to ensure his pelvis is tilted up at the front so that the spine rotates along its axis. In Richard’s case both pelvic tilt and counter rotation are necessary for strong posture. Richard’s weight is generally too far forward on the feet and the ankles are collapsing making him lean on the ski boots. This causes the hip joints to lock up somewhat in compensation – which probably adds to the pelvic tilt issues when trying to counter rotate the pelvis.

Later on during the session I explained to Clea that although it is ideal to stand on the fronts of the heels (beneath the ankle joints – allowing the subtaler joints to roll the feet onto their edges) she still required pressure against the shin to use the front of the ski. This pressure is attained by flexing at the hip joint (aided by the counter rotated hip) sinking down into the turn from the start of the turn and maintaining strong posture. Basically – seek to use heel and shin pressure and to counter the hip, flexing at the hip and if required at the knee. Remember – it’s the centre of mass that controls the skis and this is how pressure is built up and managed as a turn progresses. Body management is paramount in all of this. Good body management happens through the core.

Skating

Skating and dynamics are the main building blocks of skiing but only Clea and Mary had been previously introduced to this. Normally this is a big subject which requires a lot of attention but the idea here was to introduce it via the work being done with the hips. Countering the hip on the skating leg makes the skating action far stronger and so the two actions fit together and enhance each other. Using “Direct Method” I demonstrated by skating straight downhill and then falling to the inside of each stride to generate dynamics and turn the skating into skiing. Richard picked up on the timing immediately. Skating is a good opportunity to practice on active working of the hips and core. Correct timing in skiing comes from skating with the legs – down/up – as opposed to ski school up/down. They have built all skis since the 1960’s to work with down/up motion of the body but the schools still haven’t caught up.

Dynamics

We had a short introduction to dynamics – most of the idea being transmitted to Robert and Richard in the cable car to make use of the time. I explained the difference between weight transfer as described in statics – moving your centre of mass over your support foot – and dynamics which involves accelerating your centre of mass in the opposite direction. You simply accelerate your body in the direction it has to turn – and the ski then takes over and sustains this acceleration. There is a fixed page on dynamics here: http://skiinstruction.blogspot.fr/p/dynamics.html

Dynamics also gives natural timing – like an upside down pendulum – toppling down into a turn and back up out of it. In your mind you can remove the slope and imagine a flat surface – which is what is done effectively as you slide perpendicular to the slope (unless pivoting!). The dynamics combine with the skating to form efficient and effective skiing and rhythm and timing create a resonance (used to great effect off piste in deep snow). The legs become properly functional when used actively with this timing.

Pole planting is replaced with the “pole touch” which takes place as the body inclines downwards into the next turn – after the turn transition. This is the case whenever the skis are moving forwards (as opposed to sideways) and why you never see a racer pole planting. The arms aren’t used for this – only the body inclining. In contrast mogul skiers always pole plant.

Pivoting

The session on pivoting was even more rushed and rapid but both Clea and Mary had already worked on this so I only had to help Elspeth, Winfred and Richard by supporting them through the first attempt. There are full demos and explanations of the pivot here:

Clea needs to work on this because her main difficulty was with using the pole for support. This is where the pole plant is used – for restraining dynamics. The centre of mass still dictates the turn but the motion of it has to be held back by a pole support so that the ski doesn’t flip over onto its inside edge too soon. Clea had no weight on her pole. Setting up the body with a forward tilt at the hips, counter rotated pelvis (all adding up to hip angulation) would get the centre of mass between the uphill ski and the ski pole as soon as the downhill ski was lifted off the ground. The exercise difficulty here signals where Clea’s main area of development should be focused as this is probably affecting all of her skiing. Just a little bit of practice here brings rapid change. Clea has been using “pole planting” along with up/down timing probably all her life and this inappropriate configuration has clearly held her back. Changing to the pole touch for any forward motion and the pole plant for sideways motion (of the skis) – all with down/up motion - will free up skiing enormously. 

Unfortunately Elspeth only had one attempt at the pivot on her own and I didn’t get it on film.

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