Friday, December 30, 2011

Jason, James, Mike - Day One

Today's session started off in the clouds, wind and snow at the top of the Vert training run. The first part of the edited video here is a record of each skier's skiing prior to changing anything. For me it's important to observe each member of the group for strengths and weaknesses prior to deciding exactly how to kick off the lesson. All the skiers were basically strong so "dynamics" would be a good place to start. Mike was clearly lacking dynamics in his skiing, Jason was pushing his feet from side to side and James was failing to grip with his skis (particularly the right foot) - all key dynamics issues.

Dynamics Introduction
I explained the basics of dynamics  - showing that "transferring" weight to one leg by moving the centre of mass over it was "statics" not "dynamics" - and so was a movement in the wrong direction. Dynamics is the physics of "disequilibrium" - Newton's second law: Force = mass x acceleration. To get serious pressure on a ski you have to accelerate your centre of mass away from it - towards the turn centre. The ski itself will then continue the process of angular acceleration - providing a countervailing force to sustain the disequilibrium.

Static exercises were carried out by each skier against my shoulder which acted as a substitute force to replace dynamics - so the correct movements and feelings could be established. We then moved on to do some swings to the hill in each direction with dynamics and then to linking turns - the body following the skis for simplicity. The analogy of a motorbike turning was also used to start to impress on everyone the down/up timing required. 

I explained how the ski grew in power as dynamics (and edge angle) increased and that the ski lifts you up out of a turn. The skier's job is to fall over and the ski's job is to bring the skier back up. We rated each other on the ability to fall over - Audrey scoring the highest with 5/10. The number one thing a skier has to develop is this "dynamic range". The skier's limit is not how well he/she can stay "in balance" - but how far over he/she can incline. We then had a long ski to La Daille to practise.

Skating Introduction
Skating started off with a short race which Jason came close to winning after accelerating hard past me - just leaving me enough time to react and catch him before the end. The skating ability shown in this short race was a good predictor of the level of success that the skating exercises would have with each individual. We started off just doing basic skating step turns - with diverging skis on very gentle terrain. This progressed to three steps, two steps and finally one step during the whole turn - and eventually into parallel skiing with the full skating rhythm and timing. The down/up leg action of skating resonates clearly with the down/up cycle of dynamics for the Centre of Mass. Jason connected well with this exercise. I explained to James to use the adductor muscles on the inside of the leg and to roll the foot onto it's inside edge so as to get the skis to grip better.

Timing Introduction
Timing was fully explained in a snowplough with a neutral phase. Neutral is with a high stance. - and the skis flat pointing across the hill when skiing parallel. The turn had to start with the start of the bending of the legs - and the bending had to continue until pushing back up into neutral close to complete the turn. This exercise has to be done slowly to be able to separate all the parts and to avoid flipping the timing to up/down motion. The pole "touch" was also briefly explained - linked to the down motion at or after the start of the turn. (This is not a "pole plant"). I stopped people doing it because they all turned into "nodding donkeys" instead of keeping the arms still and upper body and just using the wrists.

Slalom Introduction
Slalom was introduced with a view to focusing on technique with the physical constraints of the poles and the clock to give useful feedback. Jason lost his dynamics completely the first time, James was limited by rotation and Mike improved due to stopping his usual contrived contortionist act when he was fighting to survive in the poles. Audrey got her fasted time ever by two clear seconds thanks to the work she had done on preventing rotation.

Pivot Introduction
To give a more complete picture of skiing skills I decided to introduce Pivoting from the uphill edges with a pole plant. I explained how once again the adduct-ors were used and how the uphill foot had to slide onto its lower edge while the ski stayed on its upper edge - the shaft of the boot holding the ski on the upper edge. This allows the adductors to smear the ski down the hill  smoothly and easily. I showed how either ski could be used or even both with the feet together. The feet come together to keep the skis below the skier and access the top edge. In racing a wide stance helps to access the inside edge of the ski early in the turn, but the pivot is  braking turn with the skis always on the uphill edges and so the feet together - as seen in elite bumps skiers. The pivot turns were still initiated by a small dose of dynamics - but not enough to cross the body over the top of the skis - so the skis actually get pulled downhill along with the body as well as the adductor muscles. I demonstrated pulling the tip inwards against a ski pole jammed in the snow and showed how different pulling inwards with the adductor is compared to pushing the heels out

Bumps Introduction
We briefly went into the bumps to show how the pivot is natural with the tips and tails of the skis in the air when on the shoulder of the bump. Bumps are formed by pivoting skis. Bumps cannot be mastered without great control of rotation - so this was an opportune moment to mention this issue for the first time along with upper/lower body separation. 

Off Piste Introduction
Returning to Val d'Isère by La Face it was an opportunity to go off piste slightly and for the skiers to experience dynamics in off-piste snow for the first time. Dynamics is a powerful tool for getting through difficult snow conditions - but you have to keep yourself down and in toward the turn centre near the end or the ski will lift you up and spit you straight out of the turn too soon - just like getting thrown out of line on a slalom course. 

No comments:

Post a Comment