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Author Topic: Pronation and Supination Correction Questions and Idea  (Read 712 times)

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Offline Query

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Pronation and Supination Correction Questions and Idea
« on: October 04, 2015, 11:06:56 AM »
Pronation and Supination Correction Questions and Idea:

Based on typical shoe shapes, most people's feet are shaped such that they are most comfortable in shoes that have arch support, i.e, a raised arch in the middle/inside portion of the bottom of the foot bed that touches their feet, but are otherwise not tilted to the left or right. Mine are a little different, possibly because one leg is about 1/4" - 1/2" longer than the other - both of my feet are most comfortable tilting a little bit downwards to the left - which I have thought of as supination in the left foot, and pronation in the right foot. In particular, I modify skate insoles to do that, else I have trouble controlling edging, because I don't have equal left-wise and right-wise pressure on the bottoms of my feet. I generally don't need to bother in other shoes, but it matters a lot to me in skates. So, on my web page on modifying boots, I say to try to equalize pressure over the foot, especially the bottoms. For example, if they feel less pressure on the left side of a foot, they should place adhesive tape or foam underneath the insole there. [Note: you can also to some extant solve the problem by shifting the blade mount position sideways.]

But a number of people who have been diagnosed with pronation have told me it works the opposite way for them - that they can control their edges better (i.e., they otherwise have trouble reaching outside edges) by placing tape or foam under the outsides of their feet.

1. So my first question is: is this typical for pronating feet, that it works better in skates to use tape under the OUTSIDE bottom portion of the foot rather than the inside?

As near as I can figure it out, what foot doctors call "pronation" or "supination" isn't always or maybe even usually an asymmetric tilt to the feet, like I have. Instead, it means that when their arches collapse due to weight support or jumps, they collapse asymmetrically. (Note: depending on how you define things and which books you read, most of us have about 5 weight support arches in each foot, which collapse a bit in jumps, thereby helping to absorb impacts and make bone fractures less frequent. There are  two main "lateral" [sideways] arches across the foot, one at the toes, one mid-foot, and 3 "longitudinal" arches extending from the heel to the toe area, one on the inside of the foot [the medial longitudinal arch, which is what most people call the "arch"], one roughly down the middle, and one on the outside of the foot. In addition, there are lots of little arches, e.g., along the toes, and across each joint of each toe.) E.g., in a pronating foot, the longitudinal arch along the inside collapses under weight support and jumps more than the outside one, and the inside arch feels "soft". Books say this is often caused by a "lax ligament" - a ligament which isn't tight, and allows the foot to tilt without much pressure.

For many people with these issues, this can lead to pain, which presumably implies tissue damage, and is therefore bad for you. For a skater, it also  means that it is hard to hold a constant tilt to an edge, as you transfer weight, take-off or land-jumps. E.g., a pronating foot may dip into a deeper inside edge as you transfer weight to it, or may lose an outside edge altogether.

So, let us see if I understand what is happening for such people: In a normal shoe, people solve the problem by putting extra tape or foam (or equivalently, an orthotic) under the collapsing arch, or, if they want to get fancy, by using an insole with stiffer foam on the collapsing side. This provides extra support for that arch - e.g., under the inside arch for a pronating foot, because when the shoe is on the ground, pressure across the width and length of the shoe forces the bottom of the shoe to be almost flat on the ground. But in a skate, such a small width of blade is on the ice at any one time, that the boot is free to tilt left or right, to equalize torque (rotational forces). Hence, putting tape or foam under the inside of an excessively collapsing arch does NOT support the arch - the boot just tilts to approximately equalize forces, rendering that technique ineffective. Though it seems to me it would support the arch a little - because the tilt of the boot will be limited as the TOP outside of the boot presses against the outside of the leg, above the ankle, thereby limiting the tilt of the boot.

OTOH, if you put the tape or foam underneath the arch on the side that doesn't collapse as much, that forces the bottom of the boot to ALWAYS (even in the air) be pressed against the foot harder on the inside (for a pronating foot), so it can't collapse further. The TOP inside of the boot presses against the inside of the leg, above the ankle, which allows this extra pressure to be created.

The problem is, this means the arch is NOT well supported, so if pronation goes to the point of pain, it would still hurt and cause damage.

2. Have I got that right?

Some people use what I consider an extreme solution. They fill space next to the mid-foot on both sides, pinching the foot across the longitudinal arches. This prevents the midfoot lateral arch from collapsing. In addition, because the foot needs to flatten when the longitudinal arches collapse, it largely prevents all the longitudinal arches from collapsing - so they can't collapse assymetrically.

That works for some people. But there are two obvious possible problems. First, it has got to be uncomfortable, and must reduce blood flow. In addition, preventing the arches from collapsing places extra stresses on the bone, so I think it increases the likelihood of a bone fracture, especially from jumps.

3. Have I got that right?

I have another solution: Support the excessively collapsing arch by putting tape or foam under it, like in a normal shoe, but also heat mold the boot with the ankle bent towards the inside. (To the outside for supinating feet.) That will create extra torque on the outside of the leg, even when the ankle isn't bent, which will force the boot to tilt in such a way as to create more pressure under the excessively collapsing (inside) arch, so support of the arch DOES occur.

3. Has anyone tried this?

Note: Obviously, none of these solutions replicate what happens inside a normal foot, and it may therefore not be as healthy or comfortable as a normal foot, because our bodies are presumably designed to work well in the normal way. In particular, we are trying to use external selective compressive pressure to compensate for insufficient internal ligament tension. This is the best we can do, non-surgically, to create similar torques.

Offline Query

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Re: Pronation and Supination Correction Questions and Idea
« Reply #1 on: October 05, 2015, 10:05:12 AM »
BTW, I have cross-posted this, to http://skatingforums.com/index.php?topic=6849.0, and to https://ca.groups.yahoo.com/neo/groups/compadultsk8s/conversations/messages/75682

Let me add something to my first post:

A lot of people just offset their blades - i.e., mount them to one side or the other, to compensate for pronation or supination.

But in of itself, that doesn't compensate for the difficulty in holding the same edge depth, or, for pain that some people have caused by arch collapse.

So many people use arch support too - using an orthotic made by a medical professional, or a home-made alternative, as discussed above.

I would claim those two things alone may not be optimal. In particular, it means most of the bodies weight is predominantly supported up one side of your leg - e.g., on the inside of the leg for pronation. That excessive muscle over-use could create muscle soreness, unbalanced muscle development, and perhaps medical issues. Making the changes inside the boot allows you to balance inside and outside leg use. Depending on the boot design, it can also gradually twist the boot out of shape, though that was most commonly discussed in connection with one boot brand (Klingbeil) that is no longer being made.

(ALL of the problems discussed in these two posts can to some extant be compensated for by muscle use. But I think it is better to compensate using equipment, to avoid the over-use issue.)

Perhaps the optimum correction for some people would be a combination of all three techniques - arch support, blade offset, and tilted heat molding.