Originally Posted by zentune
Chad, would it surprise you to learn that some learned people hip-"centric" skiing first but then actually improved their skiing once they learned to use their feet and ankles?
Not at all Zenny, it enhanced mine. Would it be surprising to learn that anklecentric skiers also may gain improvement once they learn to feel how the dynamics above the ankle work.
Originally Posted by ChuckT
Chad, I am no expert on human CNS or motion, but I think what you said about how we rely on developed synergies in our movements makes a lot of sense. But wouldn't you agree that in certain situations, for a certain outcome, a particular movement or sequence of movements is optimal?
Take a karate straight punch. To deliver the most power, you twist the hips first, a split second before launching the fist since the core muscles are more powerful but have to move a more massive trunk and therefore slower. This punch is slower and telegraphs itself more clearly to the opponent than the jab. But if you need the power, that's the best thing to do as far as I know. Move the arm before or without activating the hips wouldn't be as powerful. That's just physics and biomechanics.
If you accept that, then the notion that pushing the hips into the turn is not as efficient or versatile as tipping the feet shouldn't be considered at odd with the human body or nervous system. Consideration of forces, masses, and the characteristics of the muscles involved makes a pretty convincing case to me. I wouldn't automatically rule out the case for hips first, but I haven't heard a cogent, specific argument for it, if there is one.
I have seen elite racers making powerful movements with their upper body, scrub speed, pivot, etc. I would not be willing to accept that those are mistakes. I am more inclined to think they or their body instinctively, after much training, do what need to be done for the course, the speed, the snow... But I would venture those are not the basis for good skiing but things you can do when you are already very good. Likewise, skiing hips-centric may be a fine thing to do in some particular situations once you already know how to ski feet-centric, to borrow Zenny's terms.
I'm no expert either and I would agree Chuck, its why I wonder why the teaching paradigm only allows room for one of those sequences.
With regard to the jab analogy chuck, even a jab movement that is not using the recoil properties of the pelvic/spine/hip twist requires trunk coordination, maximizing the effectiveness of the jab still requires proper trunk organization, something on the back of the body can not interfere with contraction on the front of the body, it is not as strong not only because the synergy along the front of the body didn't get stretched before contraction (physio 101- a lengthened muscle can generate more force) but also because the muscles that fire to deliver the jab aren't interfered with from the opposing side, antagonist groups, your jab still needs optimal coordination.
Let me be clear, I am not saying it is at odds, it obviously is a mechanism and point of attention in movement that helps people, even I can feel it. Its the people calling anything other than their preference stupid. It isn't even hips first I am suggesting, that is the default some people can't get past. I said it above, a human can influence their hips through manipulation of the spine and pelvis, its what makes us unique as bipedal movers and allows us to be THE MOST energy efficient moving structure, yet somehow, skiing should begin only at my feet.
look at Josh's video. you could easily direct the same person to shift their attention to how they move their pelvis and use their whole spine above the stance leg femoral head(ball), its not as if the ankle shuts off or the leg mysteriously disappears, we still can feel the balance on the bottom of the foot, as HS said early, teaching a feeling. In fact, one could even say that as the use of the ankle and foot are so important for the fine control potential would that not dictate we keep the joint and associated muscle as relaxed as possible so the joint can be manipulated more quickly. A person would have to believe though that the ability to manipulate joint is dependent on how to minimize the effort needed. (dynamic instability rears its ugly, illogical head again) For clarity, it doesn't say no effort, its is maximizing the efficiency of the muscle control. Its also why being aware of the backhoe arms in playing piano may enhance the placement skill of the bucket (for you SMJ :) ),if your only option is to dump your pelvis over your femoral head, than yeah, your screwed, but the control of joint comes from around the whole thing, not just the bottom up.
The debate here perpetuates because some believe anything that isn't controlled at the ankle is less dynamic, static, more energy consumptive, etc, as if the rest of the body is dumb beyond command. whatever dumping issues you guys are defaulting to are as much a dysfunction of what is happening above the hip as the control issues happening below it, after all they are connected I think.
I was going to drop this, but I like the discussion with you chuck