- Combining Dynamics and Pivot
- Feet – Spiral Dynamics and Ankle Flex
- Introduction to Carving
- Sideslip
- Pivot
- Compression Turns
Combining Dynamics and Pivot
- Dynamics depends of forward motion of the skis and lateral falling/pushing of the centre of mass
- Pivot depends on lateral motion of the skis – but always with the centre of mass being driven inward (toward the turn centre) modulated by the support of a pole plant
- The two can be combined – when there is both forward and lateral motion – making overall control of trajectory and speed totally under control of the skier
- In all cases there must be active adductor muscle use – and the feet must be “everted” i.e. turned outward inside the ski boots – diverging sightly (skating stance)
- The essential element to take from combining pivot and dynamics is to execute the turn transition from the uphill edge of the uphill ski – noting that the ski enters the new turn more easily than when on its inside edge and this also prevents stemming (and body rotation)
- Additionally with the transition between the two turns being made from the uphill edge it’s easy to switch into a very tight pivot when desired
Look at the skis in the two images below. The top image is with skis carving – the bottom image skis pivoting
Feet – Spiral Dynamics and Ankle Flex
For dealing with feet pain make sure you aren’t scrunching your toes up and replace this act of tension by lifting the toes up and holding them up.
To avoid pronation of the foot and apparent “flat arches” it suffices to activate the muscles across the main body of the foot in the following manner…
- place the foot on the ground on its outside edge (supinated at the subtalar joint)
- holding the foot on its outside edge stretch the ball of the foot toward the floor
- this takes practice to increase the range of movement available
- when stretched as much a possible – while maintaining the stretch lower the ball of the foot to the ground
- maintain the muscles active to constantly prevent pronation and maintain an active arch
- you can keep pressure on the outside edge of the foot and the ball of the foot – while it’s the adductor muscles pulling inwards that holds the ski on its inside edge
Ankle Flex: One way to increase pressure on the ski fronts is to flex the ankle inside the ski boot – not by squashing the ankle but by lifting the forefoot toward the shin (still keeping pressure on the balls of the feet) and creating shin pressure on the cuffs of the ski boots. The boots then act as a lever transmitting force to the ski fronts. Gripping on ice requires pressure on the ski fronts and is strongly aided by the flexed ankle.
Introduction to Carving
- while standing still reach one leg out to the side with the ski on edge and then pull it inwards scraping the ground
- now do the same while sliding forward and maintaining some pressure on the extended ski (on gentle and wide terrain)
- the ski will carve an arc with no skidding
- as speed increases the other leg – acting as a stabiliser – can be gradually drawn closer to the extended leg by actively using the adductor muscles
- the main principal exploited here is the direct tension of “pulling” – relating to the analogy of spinning a ball on a string above your head – the only force on the ball is the string pulling inward. Here our centre of mass becomes the anchor pulling the “string”. However – with a bit more speed the “centripetal” force towards the centre comes entirely from the carving ski pushing you inwards.
- the upper body is held over the inside ski – with the belly button centred over the ski and facing the ski tip. Looking down you should see the inside ski midway between your arms.
Side Slipping (Centre of Mass)
The main practical purpose of sideslipping is to get down the mountain without picking up speed. Many learners are deprived of this skill because it is generally undervalued and has become even more neglected due to the complete domination of carving skis. Wider skis are easier for sideslipping in a greater range of conditions. Parabolic skis have some trouble gripping on ice during a sideslip, but modern “double rocker” off-piste skis give a smooth and grippy sideslip in just about every condition, including ice.
The skis are kept on edge by the lateral stiffness of the ski boot shafts. Skis over 100mm wide underfoot begin to create problems on hard snow due to the extra leverage from the edge through the shaft of the boot. Those skis can be very unpleasant on-piste and it’s one limit of how an “all round” ski can be defined. Anything wider than 100mm is not “all round”. In ski teaching the sideslip serves specifically for developing fall-line skiing. Fall-line skiing is where the skier’s body travels directly downhill and not across the hill. This would apply to bumps, steep off-piste such as couloirs and deep powder snow. Slalom is not “fall-line” skiing. The skier should be able to sideslip on either ski or both at the same time. It’s normal to start off with both skis on the snow, skis parallel and with the majority of weight on the lower ski just to get a feel for it. The stance is normally quite narrow to prevent the uphill ski from catching the lower edge. Most beginners have trouble keeping the skis close together.
It should be noticed that only the uphill edges of the skis are in contact with the snow so the downhill edges are in the air. If the fronts of the skis are pushed downhill (Joystick Control – moving the Centre of Mass forward) then there will be no resistance from the downhill edges and so the skier goes into a forward diagonal sideslip. Likewise if the tails are pushed downwards during the sideslip then it turns into a backwards diagonal sideslip. Being able to alternate between straight down the fall-line and the two diagonals is a precursor to the skill necessary for pivoting in the fall-line. Both legs need to squeeze the adductor muscles together – holding the upper legs close together. Pulling both legs together keeps a narrow stance and when the skier practices sideslipping on one leg it ensures the that the geometry of the edge angles to the slope are optimum for pivoting.
Compression Turns
Here’s a useful video showing proper compression turns at an advanced level. (Warning! – The drills used to “teach” in the clip are mainly inappropriate and fail to show the pivoting nature of bump skiing. However the advanced dynamics used by the demonstrators are correct.)
Leg Retraction
“Leg retraction” – the extended downhill leg at the end of a turn is retracted to allow the body to cross over the skis into the next turn the fastest way possible – then the new outside leg extends (independent leg action). The video below shows a top World Cup racer using this movement pattern. It’s easier to learn this pattern first and apply it to “normal” skiing before learning how to retract both legs simultaneously with the feet together to absorb bumps.