Friday, December 16, 2016

Luke & Leonie

Day One

The first video is really just a record of our starting out point.

Luke was just getting warmed up when we took the video and prior to getting to work on technique. The right leg is being defended – being held rigid on the back of the ski boot and with a significant hip rotation – largely due to this knee having been badly injured last ski season. Dynamics are strong – but not though the end of the turn.

Leonie has a wide stance and too much rotation – looking a bit robotic and stiff but with a good basic coordination and dynamics.



Feet and Adductors

Luke requested that we revise everything from the very beginning – so that seemed like a good idea. Both Luke and Leonie were however comfortable with throwing themselves downhill in dynamics so we could clearly skip that part. It seemed to me that starting from the feet would be appropriate so that’s what we did. After explaining that we need the weight over the fronts of the heels (below the ankle joints) to develop skills we worked on rocking both feet onto their inside edges – using the subtaler joints below the ankles.  When both feet are rocked onto their inside edges then the adductor muscles of both legs are pulled together – providing an anchoring or stabilization of the body through the core.

Skating across the flats on the inside edges of the feet develops the appropriate sensations and the skis are required to be diverged to do this. Next , on gentle terrain we skate around turns by displacing the centre of mass inwards in steps. So far there is no complication because the slope is very shallow. The insides of the feet are used and likewise the inside edges of the corresponding skis.

Skating across a steeper hill requires the legs and feet to remain the same but the uphill ski now rests on its outside edge – separating the edges of the foot and ski. This takes a bit of practice to get used to. The shaft of the ski boot being laterally rigid permits this separation to take place – holding the upper ski on its uphill/outside edge. Skating turns on steeper slopes then requires this action in the last half of the turn.

The skates across the steep hill were practiced and enhanced by stepping uphill slightly with each skate (we even practiced sidestepping to isolate the feelings in the feet). Now the idea was to skate across the hill with about three skates and on the final one step up onto the outside edge of the uphill ski – but remain on the inside (downhill) edge of the foot. From this position the body would fall into a turn. By standing on the uphill edge it is impossible to stem or push the ski out and the centre of mass has to be used. The foot and adductor muscles were engaged prior to the turn initiation and the airborne lower leg would also have the foot on its inside edge and those adductor muscles engaged too.

Luke felt more control over his hip rotation and Leonie immediately developed a narrower stance. Her wide stance had been due to being on the outside edge of her inside foot. The turns were reduced to one single skate at completion of the turn – onto the uphill edge of the uphill ski.

To complete the session we worked on the dynamics for the turn completion. This requires holding the downhill foot well on its inside edge – adductors tight – while making the body pass over the top of this downhill ski while still standing on it. There are quite a few counterintuitive things going on here but Luke in particular was really freed up by the action. The feet/adductors work making the action of the dynamics phases more obvious than previously.

Today I explained that a turn transition can be a two footed issue – supporting yourself coming over the downhill ski but before getting fully across it taking pressure on the outside edge of the uphill ski and extending that leg to help push the body up and out of the existing turn. Both legs and ding different jobs simultaneously – not just only stepping onto the uphill ski or flowing over the downhill ski as separate choices.



Day Two

The Core

We began with a complete indoors session – boots off – looking thoroughly at the bio-mechanics of the feet, legs, hips and torso – including “chi- hips” and the effect on the base of the spine and posture control. The indoors exercise made it even clearer how significant a role the pulling together of both sets of adductors plays – the pulling back of the hip (counter rotation of the base of the spine) aligning the thighs bones to allow the adductors to work together. Likewise the adductors and feet working this way facilitate the hip being counter rotated (in relation to the turn direction). It’s not the “hip” in reality, it’s the pelvis being counter rotated. Luke had to be careful to correct his pelvic tilt in advance to maximize the effect.

Indoors demonstration included clarifying the relation of this action to angulation and overall rotational control – and for Luke especially the ability to maintain pressure on the front of the ski boot without risk of being launched over the fronts of the skis in deep snow etc. Back out on the snow Luke applied al of this very well and looked far more centered over his skis and feet (instead of jammed in the back seat) and reported that he felt pressure on the shins for the first time ever (without collapsing the ankles).

Working from the Core Is a strenuous action which takes place during the turn transition – the hip is pulled back relative to the shoulder and held there for the whole turn duration. This action facilitates the turn transition and all the associated bio-mechanics. Motion starts from the centre. Global motion of the centre of mass corresponds to this same principle. The Core is no longer passive – it has to be active and posture will then function by reflex. (load testing was done indoors to show how the postural reflexes are triggered). Today the aim was to have a global picture of the overall coordination we are working towards. Luke did well but was tired by the end of the day and lost it a bit – but it will return all the stronger tomorrow.



Pivot – Jump Turns

Luke knew his pivoting skills were weak and so wanted to work on them. Leonie was vague regarding turn transitions – with a tendency to rush the start of the turns to get the skis securely below her – so it was decided to work on the pivoting. Controlling the hip while pivoting is not easy. Personally I can only be sure to get it completely correct once I have a rhythm going. The pivot really exposes Luke’s weakest points and his hip rotation – so it just needs some work.

One reason for working on the pivot was to encourage Leonie to start the turn with full commitment to the uphill ski. The idea is to realise the ski acts as a brake through the first half of the turn and there is no need to rush it. There is always a “pulling inwards” never a pushing out. The pole is used for support and to restrict dynamics but the pivot is controlled by the motion of the centre of mass. This is very obvious when you pivot on the “wrong” ski and the adductors are still holding the foot on its inside edge but it’s towards the outside of the turn – in which case the only active ingredient is the centre of mass.

Luke needed to work on jump turns to “soften” his movements. Jumping up requires a full leg extension and then landing with straight legs and bending to absorb the shock – smoothing out the process. Leonie managed to coordinate this better but Luke had a tendency to jump from his uphill ski instead of over his downhill ski. Absence of strong use of the poles was clear for both – so we did pivoting exercises on the “wrong” ski to encourage controlled motion of the centre of mass over this supporting ski. If you do not jump downhill slightly then you cannot get over the skis – into perpendicular and then land centred on the skis – you end up jammed in the back seat again instead. Leonie got this quite clearly.

We went off piste and used a few jump turns and short swings in places and Leonie managed to eventually put it all together and stop her rotation – holding good angualtion through the turns – building up pressure and control and then coming up and out over the ski when ready. The turns were short lively and fluid.

I explained that pure pivot has no forward momentum – only lateral slipping. Dynamics is purest when carving and there is no lateral motion of the skis. When starting a turn with dynamics we aim for pressure on the upper ski (either inside or outside edge) and a strong stance on that legs. When using pivoting it’s the same leg but with a reduction of pressure – by releasing the uphill edge grip – to slip more easily sideways. The extreme example is the jump turn where with the aid of a strong pole support the skis are fully unweighted in a jump while swinging into the turn following the centre of mass. There is a full spectrum of pressure. In many instances the new inside ski can be used instead – as a substitute – in either pivoting or carving – but the overall principles/mechanics remain the same. (You can carve or pivot totally with only one ski on)





No comments:

Post a Comment