Monday, March 24, 2014

The Role of Footwear in the Prevention of Running Injuries

This is Part 2 in a series summarizing the new research and trends in the areas of running performance and injuries...  what difference do you think your running shoes make??

Running shoes have made a rapid 'evolution' over the past century...from their humble, simple, minimal beginnings to the massive pumped up, maxed out super shoes of the 90s and beyond.  Every decade shoes came with more and more 'new technologies' promising support, stability, cushioning and improved performance.  

Most recently running shoes have been categorized into one of two main schools:

A: Traditional- big bulky shoes with support, cushioning and an elevated heel.
B: Minimal- lighter shoes minimal support or interference, that mimic bare feet.

Do you think the 'air' in Michael Jordon's shoes helped him (or you) jump?  Are high tech shoes the answer to our running problems?  Do new technologies make us better runners?  Has nature gotten it wrong?  

There is exciting research occurring in the areas footwear, running injuries and performance.  Finally, we have answers to some of these questions and a new perspective on many long standing assumptions about running shoes. 

Open your mind.  Are you ready?  Here we go:

1.  New technologies promoted annually by shoe companies are not supported by published scientific evidence. 

2. Traditional running shoes change natural biomechanics (promotion of heel strike, loss of knee alignment,  decreased cadence, increased pronation, increased vertical loading rate) all of which increase mechanical stress on the skeleton (except the foot).

3. Running shoe cushioning does not decrease the incidence of injuries. **Cushioning does decrease the stress on the foot, however.

4. Anti-pronator shoe technologies do not actually control foot pronation (foot still pronates within the shoe) or lower limb biomechanics.   

5. Running shoes increase oxygen consumption.  0.7-1% per 100g of weight (that is a lot!)- if you were a 4:15 marathoner that would translate into shaving approximately 15-20 minutes off of your time (barefoot vs traditional footwear)!  Heavy running shoes can definitely effect your performance!

6.  Minimal footwear encourages a more natural running gait through 'protective biomechanics' such as decreased vertical loading, mid to forefoot landing and increased cadence.  These features are associated with a decreased risk of injury by decreasing the ground reaction forces on the body.

7.  Transitioning to a minimal shoe does, however, increase the incidence of injuries in the calf and foot if it is done too quickly.  Individual differences will determine the appropriate rate of transition- less is more,  people who have been training in 'traditional' (that is kind of an oxymoron lol) footwear may require months or even years of very gradual transition time.  Some people may be able to transition more quickly-the rate of adaptation varies person to person.

8. Minimal running shoes are not recommended for every runner.  If you have been running in traditional shoes for more than a year, are not injured and are not interested in improving performance then stay in your shoes-they are working for you!  Additional guidelines are based on goals, current training/competition status, health conditions and specific types of acute injuries. However, most runners who wish to improve performance and decrease risk of injury will benefit from a very gradual transition to minimal footwear. 

So...what does all this mean?  Should you toss your running shoes and go barefoot?  Easy there bushman...let's look at what this means for you...

 Here is a very simple flow chart to help you determine which type of shoe, Traditional or Minimal, are best for you, from The Running Clinic.  (PECH, meaning Traditional Shoes).

Here are a couple of important things to consider:

Q: Are you currently training for a competition?  Don't make any changes until your off season.  Making changes to your training (including footwear changes) can increase your risk of injury-especially during demanding training periods- if you do not allow for adequate adaptation time.  Race season is not the time to make big changes.  Wait until the end of your season and follow a very gradual transition program (speak to a specialist for guidelines).

Q:  Are you dealing with a recent injury (less than 6 weeks)?  There are specific guidelines to determine the best shoe for you based on the type and phase of your injury- so it is best to speak with a specialist before making any changes to your footwear.  Certain injuries need to be 'protected' and allowed to heal first and all require a very gradual transition program.

In summary, there is exciting new research in the areas of footwear and running injuries.  Many runners can benefit from transitioning to a more minimal running shoe.  However, this transition must be done very gradually to avoid increasing the risk of injury to the calf and foot.  There are reasons for some people to run in traditional shoes and 'one shoe does not fit all':)

This is just an introduction to the current research- I could write another series on the research details, the relationship between footwear and the biomechanics of running, minimal footwear transitioning guidelines etc.  If you are interesting in learning more on these subjects as well as how to personalize this experience be sure to check out my upcoming Run Tech Workshop on April 5th!!

Next up...more awesome research in the areas of training, injuries and performance! 

Does running increase osteoarthritis in the knees?
Do NSAID's work?
When should you stretch?  Does stretching do anything?

Stay tuned!!

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