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Athletic development specialists dedicated to the art and science of excellence in movement

Reasons NOT to Coach Running Form: Part III

Part I and Part II

“[O]ne cannot conclude that impact forces are important factors in the development of chronic and/or acute running-related injuries. A new paradigm for impact forces during running proposes that impact forces are input signals that produce muscle tuning shortly before the next contact with the ground to minimize soft tissue vibration and/or reduce joint and tendon loading. Muscle tuning might affect fatigue, comfort, work, and performance. Experimental evidence suggests that the concept of "aligning the skeleton" with shoes, inserts, and orthotics should be reconsidered. They produce only small, not systematic. and subject-specific changes of foot and leg movement.” (Nigg 2001)

In other words, you can’t simply look at runners and determine who is applying the most mechanical stress simply based on alignment…

Case in point…..Below is a picture from the men’s 5000m at the recent US Olympic Trials. (For the complete photoset visit BYU Biomechanics.)

Had these unfortunate fellows walked into a running store, podiatrist’s office, or biomechanics lab, they might have walked out with

1)      Motion control shoes

2)      Orthotics

3)      Inserts

4)      Appointments for Sessions of “Running Form Coaching”

Had they hung out with some barefoot cult members they may have been told to discard shoes altogether...

I’m not suggesting these interventions are inherently bad.  For the right person, in the right situation these can all be useful approaches.  The problem is the thought process that funnels people to certain conclusions based on lazy thinking or people automatically trying to cure problems with whatever tool they happen to have in their toolbox.  Had skeletal alignment been the determining factor for these runners, they never would have made the start line!

Key term is “sensitivity.”  Sensitivity basically means whether a particular variable predicts what it is supposed to predict, within a suitable range of likelihood.  In this case the question is whether pronation foretells injury or impairs performance?  We certainly can’t tell from pictures alone, but it’s the relevant question to ask. 

We might think sensitivity is a sign of increased care.  Who can argue with being proactive, right?  And if you are a coach or clinician, if someone shows up to your door, they want you to do SOMETHING.  Unfortunately, too much sensitivity can be equally bad, if not worse, than not enough.   

Too much sensitivity leads to false positives.  False positives can be fatal in medicine when a risk factor classifies someone at risk and they're given a treatment they don't need.  Running isn’t quite that dangerous, so runners generally take a haphazard approach and are more willing to experiment.  Heck, worst that happens is that you’ll get a separate running injury go along with the one that you already had!

If you view these pictures of extreme pronation, and it would seem that pronation is a horrible predictor of injury.  In fairness, these guys aren’t the most representative sample for runners as a whole, but it does raise some questions.  What strategies are their bodies using to thrive with a form “flaw” that has been deemed so venomous that people will fork over hundreds (and yes, perhaps thousands!) to “fix” something like this?   If you didn’t know how fast these dudes were, you might say they are running “incorrectly” (if there is such a thing….)

The literature is mixed whether pronation and foot position are reliable predictors of injury.   One common measure is navicular drop, which is essentially a measure of foot flatness.  However…

  • Plisky (2007) studied high school runners and found no relationship between navicular drop and medial tibial stress injury.  The only factor related to medial tibial stress injury was Body Mass Index (BMI).   
  • Reinking (2006) studied two college running teams with a collective injury rate over 50% and found no relationship between pronation (as measured by navicular drop) and lower leg injury.   
  • In another collegiate running study Reinking (2007) studied five teams with a collective low leg injury rate of 68%.  None of the three foot measures (navicular drop, medial longitudinal arch, and visual foot type assessment) correlated with injury.  The only risk factor predicting injury was having a previous injury. 

Even where a connection exits, unanswered questions remain.  Does pronation actually CAUSE the injury, or does pronation change in response to pain elsewhere?  As we know pain is often unrelated to specific biomechanics, despite the lazy shorthand that many coaches use to convince people that “correct form” will cure people of injury.  It certainly helpful to ingrain sound movement habits in beginners and those with an injury may need changes, but those changes will vary by individual. 

Ultimately, as we’ve noted repeatedly, form is the body’s movement strategy based on each individual runner’s physical assets and liabilities.  To make corrections based on cosmetics alone in the name of “efficiency” or “economy” (without actually measuring for baseline and improvements in those areas), does a horrible disservice yet has built a nice little cottage industry in the running and triathlon worlds.

If honest, the best one can say is, “That looks odd and may deserve attention as many different neurological and structural pathways can lead to that outcome.  But based on biomechanics alone and what the state of evidence tells us, all we can do is guess that direct changes to form will yield improvements and hope that changes won’t make things worse.”   

Better to focus attention on areas where the relationship between risk factors and injury is more robust: protecting those with previous injury (as previous injury is highly predictive of future injury), resolving asymmetries, improving basic movement patterns, and managing stress levels with appropriate training loads. 

References

Nigg BM.  The role of impact forces and foot pronation: a new paradigm.  Clin J Sport Med. 2001 Jan;11(1):2-9.

Plisky MS, Rauh MJHeiderscheit B, Underwood FB, Tank RT.  Medial tibial stress syndrome in high school cross-country runners: incidence and risk factors.  J Orthop Sports Phys Ther. 2007 Feb;37(2):40-7.

Reinking MF, Hayes AM.  Intrinsic factors associated with exercise-related leg pain in collegiate cross-country runners.  Clin J Sport Med. 2006 Jan;16(1):10-4.

Reinking MF, Austin TM, Hayes AM.  Exercise-related leg pain in collegiate cross-country athletes: extrinsic and intrinsic risk factors.  J Orthop Sports Phys Ther. 2007 Nov;37(11):670-8.

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