Originally published on 26 January 2016

 

Do you know when you should be looking to replace your running shoes?

A recent client came in to see me with foot pain. One question I always ask is “how long have you had your footwear for?”

In this particular case, the client had owned this pair for 3 years.

This is by no means an isolated case, as many people are unaware what impact deteriorating footwear may have on their feet.

We acknowledge the importance of selecting the correct running shoe when buying new shoes, however, identifying signs of wear and deterioration in our current footwear and knowing when they should be replaced is not common knowledge.

 

It is usually left only until part of the shoe has obvious signs of degradation, be it a tear, rip or soles coming away, or maybe you like the look of the new Nike’s advertised on TV.

Traditionally running shoes were built with a midsole out of a co-polymer foam called ethyl vinyl acetate (EVA), with a view to absorb shock and cushion impact with running. Recently this cushioning technology has evolved to include gels, rubber, altered EVA, embedded air and springs. These technologies have great cushioning ability.

I briefly scoured the research to find out what impact worn footwear can have. I found the following interesting points.

 

How long should your shoes last?

Wang and colleagues (2012) also wanted to know; they set up an experiment that replicated the effect of someone running kilometers in a shoe. They found that after 500km of running the shoe loses 5% of its cushioning properties.

 

Will getting new shoes reduce your injury risk?

Newer running shoes may have a protective mechanism. Having new shoes with ‘fresh’ support and cushioning can reduce your risk of developing an injury. If you’re an injured runner be wary, as new footwear can also be a risk for developing an injury. Taunton and colleagues (2003) found that injured runners are more likely to have different shoes/brands.

 

If I wear old running shoes, will it change my running style?

Worn out running shoes can also impact your running style. The degraded cushioning can cause you to alter your running style, as different body parts adapt to help absorb the load put through the body and joints.

Old running shoes with degraded cushioning will alter your running style. Different body parts will be called upon to support those no longer supported by the worn running shoes.

This has been seen in the stance phase of gait with differences noted in the toe off, ankle joint movement and torso positioning (Kong, 2008).

“This may be a really important factor in overall performance and reducing running fatigue.”

 

Signs your shoes are ‘dead’

  1. You have worn through the rubber outer sole or have holes in the upper liner (mesh).
  2. You can bend the sole of your shoe backwards, at the point of the heel (normally this is very stiff).
  3. You can see compression lines in the midsole (looks like wrinkles).
  4. You have started to get aching feet, or sore joints after your recent runs.

 

If you are unsure of when to replace your worn footwear speak to a specialist.

Your podiatrist will definitely be able to help, however there are speciality shops such as The Running Centre and The Athletes Foot which offer sound advise on running footwear.