Injury prevention

Assessing your old running shoes

May 25, 2020

Worn out running shoes can be the cause of numerous injuries. With the rising cost of pretty much everything, running shoes included, it’s easy to be tempted to try and push your shoes as far as possible. However the potential for injury far outweighs the few extra kilometres.

Below are a few ways to check if your shoes are ready for their last run.

Old running shoes

Firstly, shoes that are worn out, simply need to be replaced. Don’t wait till “peak season”, when you’re in a panic about your training, to rush in and buy a pair of shoes in a hurry. Take your time and make sure you buy the correct shoe.

Secondly, even if your shoes are not worn out, it is a good idea to buy a spare pair. How many of us have run in the rain one day and found our shoes still wet the following day?  Also, alternating running shoes enables us to keep them in better condition for longer.

Thirdly, if you have a pair of shoes that you are particularly comfortable in and that suit your purposes, I recommend that you go out and buy yourself another pair of the identical shoes. Manufacturers of running shoes are constantly changing styles of shoes in their range and the style you are happy with may be discontinued. If a shoe works for you, it is a good idea to “stick with it”.

The best method of determining which pair of running shoes to buy is to examine your old shoes. An assessment of the wear of the shoes you’ve been using will help you in deciding the best shoe to suit your particular needs.

Wear of the outer sole

Turn the shoes upside down and look at the outer sole. The normal wear pattern will have wear on the outside of the heel and the centre of the forefoot.

Excessive wear on the outside of the forefoot indicates a “supinator”, and this type of runner would require “soft” shoes for extra cushioning.

Excessive wear on the inside of the forefoot, indicates a “pronator” and this type of runner would require “firm” shoes for good motion control.

Runners who wear out the heel sooner than the forefoot will need a harder wearing outer-sole, and a thin layer of shoe patch should be applied after every run.

Look at the shoes from behind

Stand the shoes side by side on a table and look at the shoes from behind, drawing an imaginary line down the centre of the heel counter.

Deviation inwards indicates pronation and deviation outwards indicates supination. Both these conditions require good rear-foot control i.e. a firm or reinforced heel-counter. The deviation however, may be due to a collapsed mid-sole at the heel, and one would need to measure the width of the mid-sole at equal points on the inside and outside of the heel in order to detect a collapse.

Excessive pronation will cause severe compression of the inside heel and one would need a shoe with more substantial mid-sole material. These may be in the form of either denser EVA, polyurethane, or medial plugs.

A collapsed mid-sole of a relatively new shoe indicates a fault in the shoe. With modern technology, premature collapsing of the mid-sole, either medially or laterally, has been reduced to a very small percentage. However, with the high volume of shoes manufactured, it is inevitable that flaws occur. The advantage of shopping at a specialist shoe store is that they will recognise this flaw in the manufacturing and will readily replace the shoes.

The mid-sole

The mid-sole is a very important feature of the shoe and has two functions – shock absorption and pronation control. To a large extent these two characteristics are mutually exclusive i.e. a mid-sole with good shock absorption will be soft but will have very poor pronation control. On the other hand, a shoe built to control pronation will be firm, and its shock absorption qualities will be poor. Some of the better shoes have mid-soles of varying hardness in different areas in an attempt to combine these two functions. A careful examination of the state of collapse of the mid-sole should be made regularly as the mid-sole of the shoe will inevitably wear out.

The “pinch test” can determine whether the mid-sole is supportive enough. If pinching the mid-sole between your fingers near the heel counter results in a 25% or less compression, the mid-sole is firm. A more than 25% compression indicates the mid-sole is soft. This may be by design, i.e. that the shoes were made to have a soft mid-sole, or it could be a firm mid-sole that has now softened.

Many a runner mistakenly has the worn outer sole of the shoe replaced in order to increase the mileage of a particular pair of shoes. Unfortunately this is often a useless exercise. The most important consideration of the life of a shoe is actually the mid-sole and once the mid-sole has lost its “spring” the runner is more susceptible to injury. By the time the outer sole needs to be replaced the mid-sole of the shoe is worthless.

Look at the general appearance of the shoe

There comes a time in the life of a shoe – no matter how loyal, respected and loved the shoe is – when the shoe is worn out and ready for replacement. This may manifest itself in torn uppers, loss of rigidity or shape, or a generally “battered” looking shoe.

There have been incredible advances in the research and manufacture of running shoes and we should all be able to find one that suits our needs. Use your old shoes as a guideline and shop at specialist running shoe stores where staff are able to give advice and assistance. The correct shoe can prevent many an injury and make running as pain-free and enjoyable as it should be.

Gary Sobel

Gary is a physiotherapist based in Linksfield West in Johannesburg. He has a special interest in treating sports injuries, running injuries and orthopaedics. He has also assisted a number of top Comrades and Iron Man athletes with treatment. Read more about Gary here.

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