From a biomechanical basis, edging movements that feel like they come from the ankle actually come from the movement of the femur in the hip socket.
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Most movements in skiing would be considered closed chain movements. Basically closed chain refers to the foot being in contact with a surface and weighted.
This is the big divide. If we skied in a closed chain mode, I would have to agree with you. And most skiers do, I will submit that...
But, while there are certainly differences between long GS at 100kmh and short SL turns at half that, I try to spend a big part of the turn floating or with a very light touch, setting me up for that 30% or thereabouts of max pressure. I do try to maintain ski-snow contact, but only as far as to feel the snow and enable some proprioception, but I do not ski in closed chain mode for the biggest part of the turn!!! I simply don't need the support from the snow - on the contrary, when weighted, movement is limited, so I see weightlessness precisely to allow movement that is otherwise limited!
Not only that, but since I try to direct all/most force to the outside ski, my inside half is generally unweighted throughout the turn, free to move about, in open chain mode!
The reality(science), is that the movement comes from the femur moving in the hip socket. You can believe it or not but that is the truth of it. Let’s explore the opposing opinion and talk about why the distinction is important.
I am very seriously open-minded, it's the only way to learn a lot... and I have to ask the question: what is the evidence? You said it was scientifically proven that the foot movement comes from the femur? So what is this evidence that foot movement comes from the femur rotation??
I look at Takao for instance and how his hip follows the feet around, with none to minimal femur rotation, while it is clear he's skiing with the feet, I can't help but think I'm totally missing something, when you state that there is scientifical evidence about the contrary...
And to be clear, I am not opposed to femur rotating, I use it a lot, even around its own axis. But I gotta ask, because you're saying
it comes from the femur moving in the hip socket, while I see it as
being allowed by femur moving in the hip socket. When I tip my feet, I definitely focus on and the big effort and movement is on inversion/eversion, with sufficient relaxation to allow femurs and knees ROM and any other joints enough ROM as needed, especially as the skis start to turn and I counter and/or flex/extend.
Foot tipping - and let's take the inside foot specifically, it's a bigger range of motion - is a complex movement, starting in the feet, called inversion.
Here's some articles on this movement:
Information on inversion of the foot by the AnatomyZone daily feed. Subscribe to learn interesting facts about the human body every day.
anatomyzone.com
Or the human anatomy coursework at Dartmouth:
"The chief movements of the foot distal to the ankle joint are inversion and eversion. In inversion, the sole of the foot is directed medially. In eversion, the sole is turned so that it faces laterally (see fig.
17-6). Inversion and eversion occur mainly at the subtalar and transverse tarsal joints. "
The word femur does not even appear in any of these articles.
Even this is based on pushing and they have no centripetal to hold them up and femur rotation is secondary:
p.s. full disclosure, when you add boots and skis to the equation, an amount of external femur rotation is required, to allow the tibia to point into the turn. Deep flexing of the inside foot, for those of us skiing at higher angles, complicates the equation further...
p.s.
@LiquidFeet note that inversion/eversion, i.e. foot tipping, are movements of the foot "distal to the ankle joint" i.e. "away from the ankle joint".
just sayin' that we don't tip the ankle, but the foot