Three shoe wear patterns to look for

Author: By Steve “The Footman” Manning Founder of intraini  

The wear on your shoes tell a story

Your shoes tell a subtle story of how you run.

it is more of a mystery novel then a textbook. Meaning is hidden along false paths and wear patterns. The story reveals one perspective of your running style. How your shoe responds to the treatment you give it reflects the interplay between your form and the shoes function. This should not lead you to believe that this is the complete story but it can help tell the future.

We love to analyse your old running shoes!  

At times we can accurately predict what injuries you might be experiencing and get a clearer picture of your running style merely by looking at your shoes. This might seem like magic…  but we call it technical mastery.

The real challenge is connecting what the shoe is showing with what you as a runner is experiencing.

Most times the wear patterns only tell a partial story. We get much more information during the gait analysis when we watch you run on our indoor running track.  

Why does wear happen?

Shoe wear is mostly two dimensional while running moves through three dimensions and includes static as well as dynamic forces. Wear on the outsole occurs only when there is movement between the shoe and the ground. The majority of forces actually occur while the leg and foot is pivoting or rolling over the fixed shoe.

Just looking at the wear can not tell you about all the forces that are contributing to a problem. At the same time these clues can reveal more about possible risks than the forces themselves. How the foot deviates from the ‘norm’ leads you to an understanding of why it happens and how to correct it.

Every time I see someone’s worn out shoes my mind quickly jumps through a complex process of evaluation.

I am trying to answer three pertinent questions:

Q 1. What do the wear patterns tell me about their running style?

Q 2. Are there signs of pathological (injury causing) movement patterns?

Q 3. Do these shoes suit their running style and support their likely problems?

A thorough footwear analysis can be done very quickly with only the relevant facts collected. Through experience you can eliminate the signs of normal wear and focus on those that can cause problems. A few simple questions of the runner give you extra facts about their running and injury history as well as the history of the shoe and how it worked for them. Finally, your suspicions can be confirmed or denied while observing them running in their old shoes or the new ones they are trying

on.

There are four areas I look at when checking the wear of your shoes.

1.   How much wear is there?

Mileage and shoe age:

Many injuries are merely the result of wearing shoes past their use by date. I ask people how many kilometres they average per week and then how long they have had their shoes. A quick calculation will give you a close figure even if they have overestimated their mileage or underestimated how long they have had their shoes. Anything beyond 1000kms is asking for injury and any shoe beyond twelve months old will have compromised protection regardless of its level of wear.

Cushioning is resistance:

I look to see how much resistance still exists in the forefoot midsole and whether the outsoles have worn through. The Dead Shoe test is the easiest way to tell if a shoe has worn.  Below is a picture showing how you can check this.  If you aren’t sure, then come and see our running team.  They will check it for you.

2.   Outsole wear: Footstrike and propulsion

Most people just look at the outsole wear to analyse footwear. But in fact this wear only occurs while the shoe moves against the ground during footstrike, propulsion or a pathological action.

Outsole wear and footstrike

Footstrike is perhaps the most important and misunderstood of these wearing events. The trajectory, velocity and location of footstrike can determine what will happen during the rest of the gait cycle. Of prime importance is the position of the foot at strike and the biomechanics of the individual runners musculoskeletal system.

Heel Strikers

Heel strikers typically land with their foot tilted out in a varus position with their toe high off the ground. The wear is localised on the outside edge of the heel. Contrary to many people’s mistaken belief the more you wear on the lateral edge of the heel the more you generally will

pronate (roll inwards) rather than supinate (roll outwards). Runners who are not in that position at strike wear evenly on the back of the heel and have problems during forefoot loading as the forefoot slaps onto the ground rather than rolls over it.

Midfoot strikers

As runners become more midfoot and forefoot strikers the wear begins to extend on the lateral (outside) border of the outsole. Their toes are not as high off the ground at strike and they tend to take longer to complete the footstrike part of the gait cycle. This can cause a shearing action that quickly wears the outside edge of the midfoot and forefoot.

Your body decides whether you are a forefoot or heel striker, and woe is the runner who goes against its wishes. Worse yet are those runners who try to get a heel striker’s shoe when they are a forefoot striker or visa versa. We frequently are referred runners who have been injured after only a week of running in the wrong shoe.

Outsole wear and propulsion:

The other major event of outsole wear is propulsion (toe off). Propulsion starts just before the heel lifts off the ground and finishes when the toe leaves the ground. As its name implies this is when the foot is pushing against the ground to maintain forward momentum.

The ideal wear site is underneath the toes on the lateral (outside) border of the big toe. In this position you will get the maximum force applied as well as an extended time of propulsion.

There is considerable variation from this ideal.

This variation is often the result of pathomechanics or injury causing movements.

The most common variations:

The most common variations involve Circular Wear pattern under the Forefoot, and Wear along the inside edge of the toe, and wear along the outside border.

A circular wear pattern under the forefoot

This is often the result of the big toe locking up when you try to flex at the first metatarsophalangeal joint. As the foot can not flex under this joint it is forced to pivot to maintain the necessary movement required to achieve toe off. This pivoting action causes wear under this joint or under the forefoot rather than under the toes.

Wear along the ‘inside’ edge of the big toe

Excessive pronation causes the inside border of the foot at the arch to collapse. The foot is supposed to resupinate before propulsion leading to toe off. In a foot that is excessively pronating where the arch is collapsing, arch resupination can not occur and wear occurs on the medial border (inside edge) of the big toe.

Wear along the ‘outside’ edge of the big toe

Excessive supination will do the opposite with lateral wear at the toes. This usually occurs if your foot is stiffer, does not pronate or you are an excessive Forefoot striker. It can be made worse by a shoe that has too much pronation correction or too stiff.

There are many variations on this and traps for the unwary. Some outsole wear patterns that look like they are obvious turn out to be something totally different when a gait analysis is done.

3.   Midsole wear – your cushioning

The resistance of the midsole (cushioning) to compression is what wears in the midsole.

The compression set indicates something about the magnitude and nature of forces that the midsole has been exposed to. Torsional or twisting motions will cause much greater midsole wear because they cause stretching of the midsole which it can not cope with as well. A localised loss of

resistance will indicate the axis of this torsional motion. Peaks of force may cause early destruction of the midsole and can often indicate whether someone is a heel or midfoot striker regardless of what the outsole wear patterns say.

Uneven medial-lateral heel height leads to a diagnosis of possible over-pronation or supination problems. Scuffmarks on the medial midsole can occur in runners whose legs are externally rotated (toed out) as they swing their other leg past the foot on the ground. Sometimes the midsole will conform to the shape of the foot in the midstance position showing a forefoot varus (forefoot tilted out in comparison to the rearfoot) or valgas (forefoot tilted in). The toe can wrap up causing a C shape to the midsole in response to overuse of the long extensors.

4.   Upper wear

The uppers can also show signs of deformity.

Tears and creases in the upper materials point to excessive movement in a direction that the shoe is not designed for. This can also be because the shape of the shoe does not match the shape of their foot.

Wear on the inside of the shoe, particularly at the heel, indicates excessive movement of the foot inside the shoe. Heel Counter failure or collapse can be the result of excessive rearfoot movement.

Wearing inside the heel can be a good sign that the shoe is not a great match for your running biomechanics and definitely worth investigating further.

The insole wear and molding are also useful to identify any structural or dynamic problems of the foot

What to do next?

After looking at the shoes you can get a good idea of what kinds of problems you might be at risk of getting as well as your probable running form. The major question you need to ask is, “Are my current shoes supporting my foot-type or has it been contributing to my problem?”

The next logical step is what is the ideal type of shoe to suit your foot-type based on the evidence of the wear patterns left on your old shoes. From there you can go on to safer injury-free running in shoes that feel better and last longer.

Take the time to find the right shoe for you.  Look at your wear patterns and feel what it’s like to run in the shoe.  Always compare different types, particularly if you have any of the signs above.

Our running team in the shop and in our podiatry and physiotherapy clinic are more than happy to take you through the process of trying, testing and working out what shoe will make your running so much more enjoyable.

CASE STUDY: The pseudo-pronator and excessive heel wear

I had a client who came to see me complaining of transient shin pain for the last few years. He had finally decided to get some advice because his shoes were not lasting as long as he thought they should. He had been told he was a pronator and had used a severe over-pronators shoe for most of that time. After looking at the wear patterns he was certainly wearing excessively on the outside of the heel although it was extended a bit further forward then normal. There was also a wear pattern in the medial forefoot consistent with pronation.

After seeing him running it looked like he was striking hard in the heel and pronating during propulsion. I started with a lightweight neutral shoe. The heelstrike and the pronation during propulsion disappeared. A significant change was the decrease in sound at footstrike.

After trying on a variety of other shoes it became apparent that the more rearfoot control he had the more he pronated. On examination he had a rigid rearfoot and a flexible midfoot. The stability in the heel was forcing him to fight the shoe and pivot in order to get heel lift and toe off.


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