Tuesday, January 10, 2017

David 2

With David’s knees bowing outwards there would continue to be a significant obstacle to rapid progress so the first task  for today was to attempt to sort that issue out. People can develop many issues regarding how the legs, pelvis and upper body stack up. Mostly those issues are postural but they can also be functional and depend upon experience. The first task was to find out exactly what was going on with David. We tried static exercises with the hips and posture which revealed confusion there – but there was also a confusion regarding the skating action.

 

Supporting Leg

The still image in the video clip shows David in the correct position and posture – but that was the only time he was really able to manage it. The goal is to get the upper body perched over one single hip joint. This involves preparing first with pelvic tilt, tilting the whole upper body forwards from the hips, pulling the supporting hip backwards relative to the shoulder, lifting the unsupported leg (knee forwards), hip and shoulder. The chest should be relaxed and the arms dangling freely. What’s important is that david could do this correctly – his problem is that this is all just alien to him. The hip has to get into place this way to tuck under the upper body and support the whole body solidly. You can then let the upper body pivot around the head of the femur like it is a fulcrum. Skating involves this action naturally with each stride.

 

 

In the video (prior to the still image) when David tries to adopt the stance on one leg, on skis, his posture collapses. When he skates (after the still image) he turns his upper body to face inwards on each stride instead of outwards. This last thing reveals the source of the habitual movement that is the cause of the coordination confusion. Basically there are both functional issues and postural issues to be corrected.

 

Chi-Skiing

There is a very special reason for pulling back the hip when you stand on the outside leg in a turn. If you end up with just the shoulders facing downhill then the hip will actually be pulled forwards below the fronts of your ribs and your postural reflexes will not function and protect you. If instead you face your pelvis downhill more than your shoulders then the lower spine twists slightly in the oppoiste direction – stretching the lower abdomen area and clearing the hip away from the front ribs – allowing the core muslces and postural muscles to work correctly. There is a fixed page on this subject here: http://skiinstruction.blogspot.co.uk/p/chiskiing.html

We applied the Chi principles in skiing and there was a moderate but definite improvement in David’s confidence. The results were still not consistent though.

Generally we were initiating a change of direction by starting with moving the centre of mass, then engaging the hip and the foot. The reason for moving the centre of mass first is to get the body to move over the downhill ski as it travels into the next turn – but I deliberately did not mention this so as to avoid complicating the issue at this stage.

 

Pivoting

Pivoting was taught so as to provide the understanding of the option of using the ouside edge of the ski to turn (very tightly) and to help to develop “pulling in” skills. The fixed page for pivoting is here: http://skiinstruction.blogspot.co.uk/p/pivot.html

 

Standing Up

Regardless of all the components we had worked on David was still finding it extremely difficult to stand on his supporting leg (including during pivoting). In all fairness this was only day two and he was in reality doing very well – but the mission was to rapidly attain a level of competence so there was no letting up with the pressure. The postural and functional issues are also amplified by emotional/defensive reactions, lack of adaption to accelerations, lack of recognition of the adjustment to perpendicularity when sliding and lack of experience of feedback from skis and equipment. Despite all of this David was tantalisingly close to getting it right. We tried “stomping” the supporting leg into the ground before starting the turn but that didn’t work. We tried adjusting more accurately to perpendicularity – which had a small effect. I then tried supporting David (using a pole) so that he could properly stand just on one leg as I guided him through a turn – and that did seem to work. Skiing is a one legged activity – as is skating – but good skiers don’t make this visible.

The underlying problem was that all of the above issues were conspiring to ensure that as David moved his centre of mass he would collapse his stance on his outside leg and then support himself of two legs instead. With the weight now on the inside ski he would try to twist the outside ski into the turn in desperation. Altering the order of the procedure by first standing up strongly on the uphill leg then moving the centre of mass into the turn gave David the chance to create some smooth, strong turns and feel the skills that he has been working on – with the skis making the turns for him.

The video shows David’s last descent of the day and he makes a strong first turn on the steepest part of the slope. After that turn he gets a little back – on the back of the ski boots and loses the full support of his supporting leg making the following turns less effective and secure. Just getting one turn correct is a big achievement and a solid reference point.

No comments:

Post a Comment