The pundits on Epic, whether they are boot fitters or instructors, are off the mark when trying to offer proof for their theories of skiing; their certainty about how feet function in open chain examples aren?t relevant and don?t apply in skiing function.
This is where a little knowledge and not enough practical experience at the higher levels of skiing starts to breakdown the discussion. There is no argument that the foot and ankle have ?triplaner? movement capability in certain situations. However when you analyze foot movement ?when applied in skiing situations? things change dramatically.
Foot capability and range of movement are highly controlled and influenced when equipment such as ski boots and skis are affixed. In addition in application a skier has other influences to deal with such as, ground reaction, ski mass, the weight and length of the ski, and outside forces.
If you want to really test, compare and isolate the differences between the actions that are happening from eversion of a foot outside a boot and in a ski boot, you can perform this series of comparisons. These exercises don't include the influence of outside forces, which are presented later in this article.
Test 1. Bare feet with the foot lifted or hanging from a chair. Evert your right foot, if you stop the movement at the ankle, you will see, abduction of the toes, adduction of the heel and pronation at the arch. If you allow bigger movements to effect the leg higher up you will see internal rotation of the tibia. The femur should not be affected unless you become very forceful and use your femur adductors, but this as I explained in another post is a voluntary action. In rotational movements from the foot the kinetematic chain does not apply to subconsciously recruit balancing muscles. You have to voluntarily contract the larger muscles, which in this example is not recommended as an effective skiing movement.
Test 2. Bare feet foot lightly planted on the floor. You will find slight tibia movement, and ankle movement to the medial side. If you have twisting of the foot you are recruiting other muscles than the evertors of the foot and it then becomes a deliberate attempt to rotate, which we don?t want do in functional skiing.
Test 3. Do the same tests with ski boots on.
Notice you will have similar results as test 1&2, but you might have to use more force, bigger contractions.
Test 4. Do the same with ski boots on and a ski attached. Now it takes a much greater effort or force from your evertors, which aren?t strong enough and don?t have the leverage to generate or create twist, especially with the ski even lightly on the flat floor.
If a ski boot is properly fit with an active or dynamic footbed, there is only one result from creating eversion that is possible and it?s the one you want. Reference: ?PMTS Instructor Manual? copyright 1998. page Bio-23, Section Inversion/Eversion.
?Contraction of the peroneal (muscles) everts and plantar flexes the foot. Eversion is used in skiing to engage (tip the ski) and stabilize the big toe edge of the outside ski in a turn.?
This section of the manual has extensive information of how the body can and should move when skiing. Also in ?Anyone can be an Expert Skier?, the alignment section, all references to foot movement, are presented in and with weight bearing situations, as that applies to skiing.
The effort to create eversion acts on the ski boot side wall and tips the boot (and ski) on edge. What the discussion on Epic has lost sight of, are the other dynamics of the turn and the release. Why does everyone always want and try to isolate skiing into a static bit, presentation. It?s not valid to do this and it doesn?t make it more understandable or simpler, it creates confusion. The actions of the release cause, relative to the foot?s ability, huge forces to direct the CG, to aid in transition. The ankle and foot have a role, yes, but it is so limited compared to the other dynamics occurring. Attempting or encouraging a twist, is such a low priority, and can become adversely influential in a skiers development. I can?t believe it?s consumes pages of discussion.
We should be skiing with an understanding of what movements are valid and beneficial. Movements we can feel and we can count on, for example side loading of the medial wall of the boot, with eversion of the foot. This is a stabilizing movement that helps to give the larger muscles that are recruited, through movements at the base, more precise and better control over their efforts, through the neurological system. When movements are activated by fine tuning muscles; then supported by movements by bigger muscles, the actions of the large muscles are appropriate to the needs of the movement. If movement begins with bigger muscles, as with beginning skiers, precision and control are rare.
