Running blog series: Part 7: Footwear and orthotics:
The first thing that runners think of when they start to run is footwear. Well as you can see from this current blog series it’s not all about this. That being said, this article will examine this along with orthotics (insoles). Obviously this subject area is huge, especially the orthotics side so we will only be scratching the surface.
So what do I need then and why?
Well let’s answer why first.
Injury prevention:
The causes of shin splints are many but it is considered
that training methods, training surfaces, muscle dysfunction/inflexibility, shoe
design & the biomechanics of running all impact on an increased injury risk
if these aspects are incorrect.
The different foot types are generally overpronation, oversupination
and neutral. Each type has certain characteristics and needs different things
from footwear.
Most people are overpronators to some degree. (70% has been
quoted in some literature).
Okay so if I am an overpronator what does this mean?
Pronated feet are associated with significantly higher
injury rates in the leg & foot regions (Deydre et al 2013).
Here is an image of over pronation in the foot:
Depending on the severity of your overpronation and your body’s
ability to cope with it, you will need a motion control trainer designed for
overpronators or if more severe then you
may need an anti-pronation orthotic.
Here is an example of anti-pronation orthotic correction:
So are pre-fabricated off the shelf okay or do I need custom made ones?
Well, Once again, this depends but if you need it then
Custom may be better.
What does the evidence say about orthotics?
Custom-made biomechanical insoles may be more effective than
no insoles for reducing shin splints (Yeung et al 2011).
Pronation of the foot: too much, too long or too late can
cause an increase in the dynamic valgus vector force on the patellofemoral
joint.
Pronated position of the foot compromises joint pressure
distribution and joint stability.
Some evidence exists showing that pronated feet demonstrate
greater electromyograhic (EMG) activation of invertor musculature and decrease
evertor musculature. It was also found that orthotics increased EMG activation
of tibialis anterior and peroneus longus. So it doesn’t take a genius to work
out that you can over work these structures and cause injury.
Basically prolonged pronation increases stress on pronation
control mechanisms causing compensation that increases stress on other
mechanisms.
Okay so what if I’m an oversupinator?
Supinators are less common and from a footwear perspective
they need more shock absorption. If the supination is severe enough to cause
problems then orthotics to improve this can be made for you.
Here is a photo of an over supinator:
So what does the research say for these insoles?
The use of shock absorbing insoles reduces stress fractures
in athletes & the military (Gillespie & Grant (2000).
Excessive Supination causes impaired shock absorption =
increased force ‘spikes’ to damage tissues directly.
What if I’m a neutral?
Lucky you if you are neutral then you need a neutral running
shoe and no orthotics at all. Here is a photo of neutral:
I heard certain trainers impacted on performance. Is this true?
Minimalist footwear:
There are no significant changes in running economy with use
of minimalist shoes (Sougiannis et al 2013).
But:
Another study found that minimally shod runners are modestly
but significantly more economical than traditionally shod runners regardless of
strike type, after controlling for shoe mass and stride frequency. The likely
cause of this difference is more elastic energy storage and release in the
lower extremity during minimal shoe running.
Moderate cushioning:
A moderate thickness of foam cushioning generally reduced
the metabolic cost of running (Tung et al 2013).
So economy is slightly improved with less cushioning.
However you still need what you need to prevent injury based on foot type and
only if your body is able to cope with minimalist footwear should you go there.
Are there any differences for Women?
It’s recommended that females select running footwear with
reduction of coronal plane ankle eversion in order to reduce the incidence of
injury (Sinclair et al, 2012). Basically because the biomechanical differences
it is more beneficial to have more motion control (anti-pronation).
Summary:
Clinically, comfort is the most important and relevant
feature when prescribing foot orthoses (Mündermann et al 2003). So make sure after
the getting used to period, they are comfortable and if they aren’t they are
probably wrong for you.
Ryan et al (2011) believes that the current approach of
prescribing in shoe pronation control systems on the basis of foot type is
overly simplistic and potentially injurious. So make sure you see an expert
before buying any orthotics!!
Here are some good places to find the correct running shoes
for you:
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