Foot-strike pattern and runners: advantage Barefoot runners?!

Fortunately for runners and running coaches, research continues to emerge that examines the role of “foot-strike” pattern on running, and how running barefoot or in minimalist type shoes contribute to this foot strike pattern.  Three studies published at the end of 2012 and beginning of 2013 provide more insights.

First, in a study ahead of print by Delgado et al (MSSE, 2012), the researchers found that forefoot strike (FFS) landing may not provide the protection against ‘shock absorbtion’ that has been promoted in other studies.  They found that rearfoot striking (RFS) attenuated ground reaction forces better than forefoot strike running, at least in the lumbar spine.  In this study subjects were instructed to  run with a rearfoot strike pattern as well as a forefoot strike pattern. It is not clear by the abstract whether these runners were experienced as FFS or RFS runners.

A study that has recevied quite the buzz on the internet (Twitter, Social Media, News outlets) is the study by Hatala et al (2013) who found that habitual barefoot runners in a group of northern Kenyan runners and found that the majority of these barefoot runners actually ran with a heel-strike pattern. This is quite contrary to the studies by Leiberman et al and others who have documented that habitual barefoot runners are midfoot or forefoot strikers.  But in actuality, the Hatala et al study finds similar foot strike pattern in these Kenyan runners as the speed of running increases.  When running at a comfortable endurance pace, a RFS pattern seems to work for these runners. But as they increase their running speed, they adopt a MFS or FFS pattern of landing, similar to the findings by Leiberman and others.

Similarly, in a recent ahead of  print study by Kasmer et al (2012), foot-strike landing was highly dependent on speed.  They examined the landing pattern of nearly 2000 runners at the 8.1km mark of a local marathon.  They found that 94% (yes 94%) of all runners landed with a heel-strike landing pattern!  BUT, they also found that elite performers (i.e., those running the fastest), were more likely to run with a MFS or FFS pattern.  Hence, running speed, regardless of foot wear, dictated landing style.  Faster running appears to be associated with a MFS or FFS running pattern, although runners of all speeds successfully run with RFS pattern as well.

What are the implications for barefoot runners and those who have switched to minimalist running shoes?  For the barefoot runner, these studies really don’t have much of an impact as they do not support nor challenge the practice of barefoot running.  But for the minimalist shoe runner, one take home message is to consider that simply switching to a minimalist shoe does not  guarantee a FFS or MFS running style.  Even runners in minimalist type shoes were observed to run with a RFS pattern.  To transition to a MFS or FFS running style, similar to the barefoot runner, requires more than a shoe change. It requires a conscious change in leg movement (shorter stride, focusing on landing on the midfoot or forefoot, a bit more knee flexion, higher cadence, etc.).  I will address some strategies for adopting a “barefoot” running style in a forthcoming column.

Barefoot running…Really? Or Really!

Let me first begin by stating some bias points: 1) I have been a recreational runner for 25+ years; 2) I wear running shoes; and 3) I wear orthotics.  In the past 6-months though I have made a very happy transition to “minimalist” running shoes (New Balance Minimus to be specific).  Why did I make this transition?  Morbid curiosity I suppose, spurred mainly by reading McDougal’s book Born to Run.  With that said, I am not a proponent or opponent to barefoot running…I am a proponent of minimalist running footwear.

Now some facts:

  1. McDougal’s book, contrary to so many reports on the internet, is NOT a book about barefoot running…it is a book about ultra distance running and the fact that the human species is actually quite well designed for distance running.  It is a book about individuals running tremendous distances. It is a book about a group of runners from Mexico who run in nothing more than primitive sandals on their feet (not barefoot) – basically they run in “minimalist” shoes.
  2. Barefoot (BF) runners are NOT setting world record times in distance
  3. BF running IS more efficient than shod running (running with shoes), but this efficiency has not translated into improved performance
  4. BF runners run with “different”(note the word “different” and not “better”) biomechanics than shod runners, which include the following:
    1. Decreased stride length
    2. Higher cadence (higher stride frequency)
    3. Primarily landing on the mid or forefoot, rather than the heel
    4. Reduced “impact” force, but same overall average ground reaction force as shod runners (see image below).
    5. BF running (and midfoot running in shoes) requires greater need for ankle range of motion, compared with shod runners
    6. BF running requires greater effort of the ankle plantar flexors (gastrocnemius, soleus, etc.), compared with shod runners
    7. BF running results in greater load to the forefoot, compared with shod runners

    From Lieberman et al 2008:  Note, the maximum GRF remains the same whether barefoot running with a heel strike, shoe running with a heel strike, or barefoot running with midfoot strike. Is the impact transient (first spike) the issue?

  5. These biomechanical differences (4a-g) have not been associated with increase or decrease injury risk. The ONLY factors associated with injury risk in runners are “pre-existing” injuries, weekly mileage, age, and training errors (and possible relationships to “foot type”).
  6. Of these biomechanical differences, it is quite interesting that “elite” shod runners tend to run with similar biomechanics as barefoot runners – this suggests that the body adapts its running to be most effective, regardless of footwear.  Nearly 40% of “elite” shod runners use a forefoot landing style with high stride frequency and decreased stride length (less stance and float time).  This running form is seen in shod runners.
  7. BUT, with all the amazing “improvements” to the modern running shoe, the injury prevalence in runners has NOT diminished (35-70%) in the past 40 years.
  8. BF running has NOT been proven to reduce injury risk; in fact anecdotal evidence from sports medicine folks report an increase in Achilles tendon pathology, calf strain, and midfoot related injuries in barefoot runners.  However, anecdotally, many runners report less injury when switching to barefoot running – as evidenced by a new study by Goss and Gross (2012) – I’ll write more on that “self-report” study another time.  But, in a paper they wrote in a prior study, they suspect forefoot landing might place the runner at greater injury risk to the ankle muscles and the forefoot.

    Goss and Gross 2012

Two last points:

  1. BF running “might” increase foot muscle strength, but there is no evidence that this is of any use for injury prevention
  2. Modern running shoes, contrary to the internet, are not “bad” for runners, but in the same light they have not proven to be helpful in preventing injuries. There is no evidence in either case.  Modern running shoes are confining, restrictive, and expensive, but, the new Minimalist shoes are also expensive (my own pair of NB Minimus retail for over $100).

So, where do these facts leave us? There is no evidence to support barefoot running claims as less injurious to the runner; there is no evidence to support internet claims that running shoes are harmful. And, well, in modern society, finding a surface to run barefoot safely (glass, debris, hot pavement, cold pavement, etc.) is increasingly challenging. Hence the advantage of the minimalist running shoe.

Are minimalist running shoes better than the typical modern day running shoe? I don’t know because we don’t have any research evidence to support these claims. Are they lighter – yes. Do they force the runner to run more like a barefoot runner (or like an elite runner) – yes. Is this a good thing? I don’t know. But it seems logical that for those individuals who would like to run barefoot, but fear injuries to the bottom of the foot, the minimalist shoe is a viable option.

It also seems logical that for the runner without any inherent biomechanical issues, the minimalist shoe is a viable option that will allow this runner to achieve a more efficient running form.

It is possible too that for the biomechanically challenged foot (read abnormal pronator), that the minimalist shoe might be a viable option, reducing demand to the rearfoot (subtalar joint) and placing greater demand on the forefoot. However, the biomechanically challenged foot (read hallux valgus, hallux rigidus) might be better advised to continue using a standard, modern running shoe.

Do you, or do you know a runner, wishing to go au natural?  Or, at least transition to a minimalist shoe?  If so, here is some “transition” advice:

  1. Running barefoot or with minimalist shoe requires the runner to land on the forefoot or ball of the foot. This does not happen naturally and requires some “break” in time – some training and adaptation time.  Just like with any new exercise (read “stress”) the body needs time to adapt.
    1. Begin with shorter runs
    2. Alternate days between minimalist and standard running shoe until comfortable form feels natural – this may take up to 3-months (according to research)
    3. Find a gentle hill and train running/walking uphill.  Uphill requires forefoot loading and places greater stress on the calf muscles – those muscles needed for forefoot running.  Treat this as a dosage exercise, like any other strength/conditioning program…perhaps a few sets 2-3 days/week.
  2. Be prepared to shorten your stride
  3. and quicken your cadence
  4. and land more softly when running in minimalist shoes

Until we have sufficient research to support/refute all the internet claims, proceed with caution when making the switch from a standard running shoe to a minimalist running shoe, or even to BF running.  And since we have sufficient research to support the benefits of running, Just Do…oh wait, I am not about to support that slogan…Just get out and run!

Dan | Follow me on Twitter at https://twitter.com/danielcip3