Sock with a sole: training tool for foreward foot strike during running

Warning: Opinion only (albeit hopefully based on science and experience : )

Having examined much of the research on barefoot running, minimalist shoe running, foot strike patterns, and the relationship of these variables to injury risk and performance, I’ve come to two (2) conclusions: 1) Running is risky (over 50% of all runners will experience injury at some point in his/her career) and 2) Injury risk varies depending on foot strike running style.  All runners, regardless of foot strike pattern, are at risk of injury because running is a tremendous musculoskeletal stress.  Fortunately, the musculoskeletal system is quite adept at adapting to stress; if the runner properly “doses” the stresses to the body, the body will happily and effectively adapt. But if the runner over-doses these stresses, the body will react negatively (i.e., injuries), regardless of the foot strike landing style, shoe wear (or lack thereof), experience, etc.

In terms of injury risk, it appears that barefoot runners (and runners who land with a midfoot or forefoot strike) have lower risk of injury at the knee and hip, but perhaps an elevated risk of injury at the foot and Achilles tendon.  There remains insufficient evidence to verify this – I make this observation strictly based on biomechanical studies of landing forces.  Heel strike runners (most of us) place greater stresses on the knee and hip, compared with midfoot/forefoot strikers.  So, while each style “reduces” risk of injury, each style also comes with elevated risk of injury.  The key remains: Dosage!  But, there is a slowly growing body of evidence to suggest that forefoot/midfoot strike landing might, I repeat might, be perhaps a bit more safe than heel strike landing.  With that said, how might one transition to a forefoot/midfoot strike runner?  The key is likely foot wear.

There are dozens of “minimalist” running shoes on the market.  However, based on a few observational studies, even running in a minimalist shoe does not guarantee a foreward striking running style.  Heel striking continues to be observed in runners even when wearing minimalist shoes. I suspect part of the dilemma is the fact that even the most minimal of minimalist  “running shoes” remain too similar to their standard running shoe cousins: in general appearance (laces, heel counter, uppers, outer sole, etc.).  Anecdotally, running friends have told me they need to really “concentrate” on their running form, in order to land more forward on the foot, even when wearing their “minimalist” shoes. I have experienced similar when testing multiple different minimalist shoes.  That is, until I tried on a pair of what I would call “Socks with a sole” (Sockwa G3).

What is more minimal than a sock?  Given that a sock provides absolutely no support to the foot, and essentially no protection to the bottom of the foot, a sock is truly minimal.  The Sockwa is basically one slight upgrade over a sock in that it adds a protective sole to the bottom of the sock.  When I ran in the G3, I was actually forced to land with a foreward strike pattern – identical to how I run when barefoot.  I am not a barefoot runner, but of course I do run barefoot (to get the mail, to run home from the beach, etc.).  The Sockwa G3 is as close to running barefoot as I have experienced – and no comparison at all to the “minimalist” running shoes on the market. This is not to disparage minimalist running shoes but only to point out that a sock is about as close to barefoot running as a shoe can become.

I have successfully completed several runs now in the G3 and have had no difficulty at all maintaining a forward striking running style.  It happens naturally, without much thought.  This is quite different than my experiences with my “minimalist” shoes in which I have to consciously work on my stride to maintain a forward strike running style. Again, this is my own personal experience.  But I have found in a short time that the G3 is a better foot cover for running in terms of promoting a barefoot type running technique.

So, if your running goal includes transitioning to a foreward foot strike running style (like barefoot running) because you hope to change your risk of injury, I certainly recommend giving the G3 a try.  And as with all new stress, don’t over-dose.  Gradually add new running stresses – listening to your body as it reacts to these stressors.  If you are an experienced runner, but new to foreward strike landing, or new to a minimalist shoe, begin with shorter runs to give your Achilles tendon and your foot bones (the tarsals and metatarsals in particular) a chance to adapt to this new running form.  If you are new runner, ditto J  I cannot recommend a specific level of dosage – this is person dependent – but your body should be able to provide you with important feedback – so listen carefully to what it is telling you.





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.

What the Sockwa?

Being quite new to “minimalist” running, I have tried to keep up on all the new research that continues to emerge on the topic of Barefoot (BF) running and Minimalist Shoe (MS) running.  I am a Traditional Shoe (TS) runner having run in stable, motion control shoes for 20+ years.  And during most of those years I’ve worn semi-rigid custom orthotics in my shoes. The original reaon for the orthotics was persistent hip and lateral knee pain when I first started running – and I just continued wearing the orthotics because they helped so well at the time.

I recently made the leap to MS (Minimal shoe) running, tossing my orthotics and stable, motion control shoes for the New Balance “Minimus” running shoe. I fell in love almost immediately – I loved the light weight shoe, and the fact that I could almost, almost, feel the ground beneath my feet.  But, I still felt like I was running like a TS runner – even with the minimal heel of the New Balance Minimalist – I continue to land with a heel strike running form. The good news was that I was able to run with minimal protection and without orthotics and without my old hip or knee pain.  I cannot attribute the minimal shoe or lack of orthotics to painfree running – it is just as likely that 20 years of running allowed me to positively adapt physically to running.

In any case I was also intrigued by the notion of barefoot running (BF running) and have the ambition to one day run “like” the barefoot runner.  But, I want sufficient protection to the bottom of my feet. As most now know, BF embraces a midfoot or forefoot landing style of the foot, rather than the traditional heel strike pattern. I will be writing more about what we know in the research literature about the pros/cons of midfoot/forefoot striking compared with heel striking, but suffice to say there is sufficient research to entice me to try to make this transition as a runner.

Knowing that “true” barefoot running would require that I learn to land on my midfoot and/or forefoot (at least for higher speed running), I knew I needed to learn how to transition from my heel striking ways to that of the midfoot striker.  Unfortunately, the Minimus shoe was a bit too close to the traditional shoe to help me  sufficiently with this transition.  And while I am sure the Vibram Five-Finger would likely do the trick, I am “toe-space” sensitive. I am quite sure I would not tolerate toe socks – I cannot tolerate a single “big toe thong” type sandle…so, something between each toe was not going to work.

And then I stumbled upon Sockwa – through Twitter.  Clever name (Sockwa = sock with attitude) – these “shoes” slip on almost like a crew cut sock but they have sufficient minimal rubber on the sole to offer protection to the bottom of the foot.  The Sockwa G3 (which is what I am wearing) are deigned to allow for running outdoors. And because they have absolutely no heel reinforcement, no heel thickness at all, the Sockwa encourages the runner to land softly on the midfoot or forefoot, essentially as if running barefoot.  As soon as I slipped on my Sockwa G3′s I knew I was in for a treat.  My feet felt almost naked…and I was excited to go for a short run.  Kind of reminded me of the moccasins I wore as  kid playing in the backyard.

My first run was a combination of concrete road surface, gravel road, and rock/dirt trail.  I kept the run short (about 3-miles) but right from the start I knew I was landing on my midfoot and not on my heels. Even when I tried to land on my heels I did not like the sensation and immediately resorted to midfoot landing. This naturally required a slightly higher cadence, a shorter stride, and a bit more “tall” running posture – but, well, that is actually the idea – and the basic requirement of BF running.  I only wish I had picked a route that also had some minor hills – I just felt like I wanted to surge – which is unusual for me as a runner.  What a total joy – and I am not one to gush about running.  I anxiously await to see how I feel tomorrow…and am looking foward to my next run.  The G3 is super comfortable and feels almost as if running without anything on my feet - about as close to BF running as I’ll get – but with the requisite protection.  Thank you Sockwa!!!!!

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