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High hips forward for learning

It's reasonable to think that lots of progressing beginners and intermediates can be helped by the mental image of "high hips forward" -- as a way to help them avoid having part of their weight back on the previous ski, while they're aready starting the next leg-push with the other ski.

The idea is that the hips tend to drop down and back a bit during the leg-push phase, so bring them up and forward during the glide phase.

High hips forward for normal skiing

If their hips are way behind their ankle joint, most skiers do not have the leg-strength to quasi-isometrically support their whole upper body weight on the next kick ski, without some support from the previous leg-push ski.  So they need to bring their hips forward to roughly over their ankle joint in order to commit full body weight to the leg-push ski.  

The obvious normal way to bring the hips forward is to use the quadriceps upper leg muscles to extend the knee joint -- which raises the hip joint up as well as forward.  So the normal way for most skiers to achieve committed side-to-side weight transfer is to bring the hips forward "higher", at least higher than they were at the end of the previous kick.  See 

more on Balance and Weight Commitment

Questioned for serious racing

Recently (in 2002) some racing coaches have been saying that moving the hip high is a hindrance to speed or efficiency -- instead the more knee-bend, the more leg-push power. 

Here are some of my thoughts on that, based on physics: 

  • It is true that with a lower hip, the possible horizontal length of the leg-push against the snow is greater.  Since this length is a key bottleneck to the speed of classic striding, an approach to increasing this length is worth considering. 

  • But when using this approach of an overall lower hip, even if the hip is not high in absolute measurement, it can still be relatively higher at the start of the next leg-push than it was at the end of the previous leg-push.  That's what I've observed in videos of some of the very best racers from 1997.  

  • This lifting of the hip during the passive glide phase is not wasted energy, since the elite racers can convert much of the gravitational potential energy into forward-push force, by applying it to the pole-push or to the next leg-push.

    • It's a way to use the powerful knee-extension leg muscles (e.g. quadriceps ) to add power to classic striding.  Because after the weight of the hips and upper body has been lifted higher, it adds more power when it drops back down to help drive the start of the pole-push and/or when it continues to drop down during the next leg-push.

    • The movement of extending the knee joint to lift the hips forward helps pump more blood through the big leg muscles, so there is less lactic acid build-up than if they held a static position with their legs. 

  • Many elite racers tend to drop lower the hip lower at the end of the leg-push stroke anyway, so the only possible gain in stroke length from a low-hip strategy is by reaching further foward at the start of the leg-stroke. 

  • It would be possible to recover the hip forward without raising it higher, if the ankle were simultaneously flexed to bring the knee joint lower.  I have not yet checked more recent videos to see if elite racers are now doing that.  But if the ankle is flexed more, then the new leg-push foot is not reaching further forward, so the horizontal length of the leg-stroke is not increased.  

  • So the only way remaining to keep the hips low and reach the new leg-push further forward is to not bring the hips forward.  That is, start the new leg-push while the hip is still "sitting back" substantially behind the ankle.  

  • This is theoretically possible, but it requires: 

(a) more quasi-isometric strength in quadriceps; 

(b) more quasi-isometric strength in calf and foot muscles to press toe and ball of foot; 

(c) more stress on the knee joint. 

  • Some elite racers seen already in 1997 videos were initiating the next leg-push with the hip joint a little behind the ankle joint.  So perhaps for elite racers it's not a question of whether to lag the hips behind the ankle, but how much?

    • How many non-elite racers have how much of these kinds of "more"?  

    • How many non-racers have barely any of them? 

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