ARE YOUR SHOES CAUSING RUNNING INJURIES?

By Steve Manning (intraining podiatrist)

The most common reason for a disruption to your training is an injury.  

The most common risk factor in running injuries are training errors.  We have that covered for our runners in the Intraining Running School program.

However, there are a number of other risk factors including structural abnormalities, pathological gait patterns, a change in running terrain, trauma and FOOTWEAR.  

Many people in the running community latch on to one of these factors as if that is the only way to avoid injury.  All you need to do to run injury free is to change to a midfoot strike (wrong) or go to a minimalist shoe (wrong again) or stretch more (increases risk of injury) or run on a softer surface (nope) or improve your core stability (if only that were true).  The evidence for all of these risks factors is sketchy but that is mostly because runners might look the same but are actually very different.  

Your structure determines the best way to run and the best shoe to wear and even the best way to train.  While genetics is probably the major variable in this, training can change some structural factors as you improve strength and gravitate towards your ideal structural balance.

Consistent, progressive and balanced training more than any other factor will reduce your risk of injury.  However, that does not mean that you should not create strategies to deal with the other risk factors.  These strategies will have different levels of importance for each runner.

One of the key avoidable risk factors for running injuries is wearing worn-out shoes.

Running is a relatively cheap sport.  A pair of good quality running shoes will cost a bit over $200 and will last around 600 to 800km.  That comes out to about 25 cents per kilometre or $2.50 per hour if you run at 6 minutes per kilometre. 

The problem with knowing when your shoes are dead is that it is hard to tell the difference from one day to the next.  Looking at the outsole is not a good indicator of shoe wear for most people.  The part of the shoe that usually wears out first is the midsole in the forefoot of the shoe.  By the time you wear through the outsole or uppers, the midsole has usually been dead for a few months.

The midsole is where the cushioning is created.  As midsoles age, they lose their resistance to compression and go soft.  This lack of resistance means they can bottom out at the same time as the softness reduces your feel for the ground.  Together these two things result in an increase in impact forces that go up to your legs.  This increase in stress is thought to then increase the risk of something breaking down.

So what can you do to keep track of your shoe wear and reduce footwear related injury risk?  Here are some strategies to make sure your running shoes are not contributing to your injuries.

FOOTWEAR Risk Reduction STRATEGIES:

1. Record when you purchased your shoes:
   • At intraining, we keep a record of your shoe purchases. You can always call and ask when you last purchased your shoes.  You can also write the date of your purchase underneath the insole or on the side of the midsole.  It is then just a matter of multiplying your average weekly kilometres by how many weeks you have had your shoes.  For example, if you run 40km a week then you will get to 800km in 20 weeks or less than 5 months.
2. Record your shoe kilometres:
   • Apps like Strava allow you to record which shoe you ran in for a session.  They then give you a running tally of how many kilometres a shoe has done.  You can also set up an alarm system where Strava will let you know when a shoe has met a particular mileage mark.  Alternatively, you can keep a running tally on a spreadsheet and start to check your shoes more regularly when they have reached 500km.
3. Check your shoes regularly: 
   • Perhaps the best way to check if your shoes are dead is to keep track of how they feel in training.  Can you start to feel rocks through the midsole or does it feel like the road has become harder?  Have your feet or legs been getting sore after a run?  Do you feel like you are unstable in the shoes?  All of these things may be an indication that it is time to retire a shoe.
4. The dead shoe test:
   • The main way we check in our clinic or in the store for the shoes wear is by doing the dead shoe test.  Resistance is cushioning and a new shoe will resist compression.  Because the forefoot is the thinnest part of the midsole it is usually the first to break down.  If you bend the shoe’s forefoot the opposite way it normally bends when you are running then it should have good resistance if the cushioning is still intact.  If you can touch the toe to the heel then it has probably been dead for a while and should have been replaced earlier.  This test does not work for every shoe as racing shoes may have this flexibility from the start.  Carbon fibre plates and maximal stack height midsoles may have this resistance even when worn out.
5. Alternate between two pair of shoes.
   • As previously mentioned it can be hard to tell that a shoe has worn out from one day to the next.  One way of reducing this risk is by having two pair of shoes that you alternate between runs.  When you find that you no longer want to run in one pair they are probably worn out. 
6. Wear two different types of shoes
   • Running involves the same stress to the same structures over long time periods.  This is especially true for road running.  The same constant stress can lead to fatigue of specific tissues like bones and tendons.  You can reduce this risk factor by having two different types of shoes.  That way the stress will change from one run to the next. It is even better if one shoe is heavier and more supportive and one is lighter and more flexible.
7. Let your feet choose the best shoe
   • When you purchase your running shoes you will often have some preconceptions of what shoe to buy.  You may be influenced by what you have worn before, what has worked for a friend, a recommendation from a health practitioner, what an elite athlete wears,  shoe company marketing or even how a shoe looks.  However, none of these things will help you buy the best shoe to suit you.  The best thing to do is to come into the shop with an open mind.  You should let your feet choose the best shoe to suit you.  Research at the University of Calgary has shown that if you choose your shoes on comfort alone you will have a reduced risk of injury.
8. Get the best advice from the running shoe experts at intraining.
   • At intraining, we have been helping runners find the best shoes to wear since 1979.  Our unique fitting process will help match you to a shoe using the most up to date scientific evidence.  We will not try to sell you the most expensive pair with gimmicks and technological jargon.  Our goal is to give you a great run.  We think that can be achieved by finding you the best shoe regardless of price or popularity.  If you have had problems finding a good shoe then make an appointment with one of our Podiatrists for a complete biomechanical assessment and footwear fitting. 

Book an appointment here!

Donate your old shoes to charity.

intraining has a continual donation program for old shoes.  Your runners will get to the point that they are no longer suitable for running.  However, they may still be in good enough shape to wear around.  You can only have so many shoes to mow the lawn.  Why not pass them on so they can live again for those in need.  Over the years we have donated thousands of old running shoes to charity.  That includes PNG, India and Islander and Aboriginal communities.  Please only donate shoes that have laces and insoles and are in good shape otherwise.  A certain number of donated shoes go straight to the bin because they are too worn out.  Your generosity can make a difference and may even inspire a future Olympian.