Running Myth 5: Clarifying the link between Biomechanics and Running Injuries

MYTH

Anatomical abnormalities of the lower body such as flat feet or knee valgus make people more susceptible to running injuries.

REALITY

Research shows there is *generally no relationship between biomechanical abnormalities and pathologies in the lower limbs

*read further for the exceptions

ELABORATION

In a world that admires perfection, it is easy to get hung up on finding absolute symmetry in our bodies. As a Physio and Pilates Instructor, I spend lots of time talking to people about finding a “neutral” position and giving advice on postural alignment. But the wonderful thing about humans is that we are all unique and each of us have own version of “neutral”. Some of us are born with flat feet, others with high arches. Some people are pigeon toed, others stand in a plie! These are all considered anatomical abnormalities. But when do these variances become a risk factor for injuries?

There has been extensive research published investigating the link between abnormal biomechanics and injury. Let’s take the topic of flat feet or excessive pronation as a causative factor in lower limb pathologies such as Achilles tendinopathy or plantar fasciitis. There are numerous studies that cite excessive pronation as a risk factor in running injuries, yet numerous others which suggest the opposite. Flat, rigid feet are a common feature among some of the world’s highest ranking African runners yet these athletes are not suffering from recurrent bouts of plantar fasciitis. So what is the missing link you ask?

When are abnormal biomechanics considered pathological?

  • If there is a significant asymmetry eg.> 2cm leg length discrepancy confirmed on non weight bearing X-ray
  • New onset of abnormal biomechanics, secondary to an acute change
  • Significant weakness that causes a gross change to lower limb biomechanics

With sudden changes in biomechanics, the body does not have time to adapt to the new mechanical stress and tissue breakdown occurs. We once again, refer back to the very first post of this series on the cause of running injuries.

BOTTOM LINE

To my fellow Physios and fitness advocates:

  • Remember to look at the bigger picture – What has changed recently? Is the causative factor really the flat feet that they’ve been running with for 20 years or the recent increase in their training schedule?
  • Look at gross range of motion and biomechanics using functional tests such as the step down and look for significant biomechanical faults
  • Is a biomechanical fault long standing or of new onset eg. excessive pronation throughout life or due to recent lumbar nerve root compression

To my fellow runners:

  • Be aware of any seemingly insignificant strains or sprains that occur during your runs. Take note and mention these to your physiotherapist if an injury crops up. There may be a link that will help determine the factors involved.
  • Be cautious in your return to running after sustaining an injury. Consult a physiotherapist with experience in running injury prevention to make sure you are ready to return to training and have addressed any new biomechanical faults.
  • As always, allow your body time to adapt whether you are new to running, returning after an injury, or beginning the new season.

Stay tuned for #TeamJina’s next post by @linaenglundpt this Thursday. Lina will be touching on biomechanics again in relation to orthotics.

For more Physio related information, stay updated by following @jeanlewispt and @linaenglundpt on Twitter.

References: “New Trends in the Prevention of Running Injuries” – Blaise Dubois BScPT, The Running Clinic

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1 Comment

  1. Andrew says:

    great blog Jean! 
    The thing about common sense is….. It’s not very common ! 

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