PRONATION: FORCES IN THE FEET – PART 3


As stated in my previous 2 posts on pronation there is a camp that advocates stabilizing the foot in a neutral position based on the unproven theory that this is the most functional configuration for skiing.

A neutral position of the foot is an alignment in which the foot is neither pronated or supinated. In a neutral configuration, an arbitrary reference axis would not deviate when the other major joints of the foot and leg;  tibial-talar, knee and hip joints, articulate.

The graphic below shows three configurations of the right foot: Left – pronated 20 degrees, Centre – neutral, Right – Supinated 30 degrees. According to the camp that advocates stabilizing the foot in neutral with footbeds and alignment, the foot should not pronate or supinate in skiing.

Stabilize literally means to prevent change.

Screen Shot 2014-02-08 at 12.53.21 PM

Before taking this theory to the ski slopes to assess the impact, let’s have a look at how stabilizing the foot (actually, the feet) in neutral affects the ability to align forces when standing on a flat, horizontal, solid surface.

Locked Neutral

Well, this doesn’t seem to work too well does it? In fact, it doesn’t work at all. But hey, this is quiet standing on a flat, solid, horizontal surface. Nothing like skiing when the feet are on edge. Things will be different in skiing….. won’t they? We’ll find out in the next post.

2 comments

  1. maybe some people are confused about what pronation is ? I thought a pronated person standing in ski boots with no footbed would tend to have knees together but feet apart, causing problems for grabbing an edge on that outside ski since leg already angled in on a flat ski.
    and then on flexing that knee goes inside even more, making it even harder to find edge with knee angulation …but then too the inside leg gets in the way of the outside leg too……This is all just an impression of pronation . I’m curious if the impression is wrong ? This I think is an impression that lots of people have including me about how pronation affects skiing …So I look forward to more…of how this all works..

    1. Your perception is correct. Few people understand what pronation is, including medical professionals, and especially the role pronation plays in skiing. The issues you are referring to are due to sublaxation of the knee and joints of the ankle complex caused by the ski boot preventing the foot from becoming structurally functional in terms of activation of what is called the ‘auto support’ mechanism. A metaphor is an umbrella that is partially open. In this state the membrane between the ribs is loose. So the umbrella has no structural shape. When the umbrella is fully open and locked, the membrane between the ribs is taut and the umbrella has structure. The auto support mechanism of the foot works in a similar manner when the weight of the body is applied to the foot. Functional pronation occurs in gait on the supporting foot in response to a sequential recruitment of the major muscles on the back of the leg in progressive extension and specific joint angles; soleus-gastrocnemius-hamstrings. There is much mystique about Ted Ligety and extension. Ligety has learned (probably unconsciously) how to use the auto-support activation sequence to engage an auto-edging mechanism as have Shiffrin, Vonn and all the great natural skiers. Keep giving me the feedback until you understand how pronation works. What I call the Ski Move is simple and easy to teach. But the science behind it is extremely complex. In addition, few can make the Ski Move because ski boots, especially components like footbeds and an injected and thermoformable liners, are intentionally blocking the necessary joint actions.

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