Sole Searching: Challenging the Wisdom of Training in Shoes

Monday, February 22nd, 2010

      by Heather Morgan       

              Unless you live under a rock under yet another rock, you have no doubt been privy to the movement toward back to basics training—right down to questioning the efficacy of footwear.  Even sport shoe-making giants have been on to this for a while and are now ironically designing shoes for…{wait for it}… barefoot training!  Then there are the purists belonging to groups who advocate baring it all (below the shin), and who likely scoff at those in the barefoot-like shoes just like they are scoffed at by, well, everyone else. 

                I’m not going to lie. I’m not a fan of sport training shoes or shoes in general.  Yet, I wear them nearly all of the time.  It has nothing to do with shoes being uncomfortable.  In fact, I’m much more comfy in my cross-trainers.  But I suspect that that’s partly because my feet don’t have to work so hard when they are in them.  After all, they are already dysfunctional: limited big toe dorsiflexion (when you lift the toe up off the floor) due to arthritis, heel spurs, and plantar (bottom surface of foot) fascia that never hesitates to let me know that I did a few more foot strikes than it cared to bear the brunt of in a given week.  Rather, I’m “not a fan” because the logical part of me can put it together that, in the grand scheme of things, humans have not been donning shoes on their “dogs” all that long.  And in practice I’ve seen way too many foot, knee, hip, back, and higher up issues borne of improper foot mechanics and gait.  Many of which are perpetuated, and even created, by modern footwear.

                To start, just about any shoe you put on—for training or otherwise—has a higher heel than forefoot.  The only shoes I own that are not like this are my Earth shoes with a negative heel (one that is lower than the forefoot).  They are hideous, but they do work.  I can’t say much about the new rocker sole type“fitness shoes”, but the feedback from wearers has been positive.  Anyhow, it is easy for someone like me, who does what I do all day long, to see the link between elevated heels, short calves, tight hip flexors, and all of the other things that come along with anterior pelvic tilt.  Most notably low back pain resulting from the relative weakening of the hamstrings, gluteals, and abdominals, while low back musculature shortens and tightens.  That’s a classic in the realm of common posture distortions.   But don’t equate “common” with normal, as it can just as easily be seen as epidemic.  Sort of like how the incidence of diabetes shot to the moon with the advent of processed foods, sugars, and artificial sweeteners, a similar phenomenon came about in the 1970’s when the first very cushioned running shoes were created.  Running as a hobby then took off and the field of sport biomechanics exploded shortly thereafter.   According to some, the latter was in response to the need to deal with the injuries of the former. 

“The ankle bone’s connected to the knee bone…”

                One study I reviewed examined the effect of running shoes on lower extremity (hip, knee, ankle) joint torques.  Torque is a twisting force. They looked at a pile of runners of all ability levels and evaluated each of their running gaits both barefoot and with running shoes on.  All subjects wore the same design shoe for the study.  I’ll have to admit that I was shocked when their results showed quite conclusively that there were not only increased torques on all joint areas when wearing running shoes versus being barefoot, but that the torque increases were “disproportionately large” at the hip and knee especially!  They even described the effect as greater than that of wearing high-heeled shoes during walking, and attributed their findings to the elevated heel and increased material in the medial aspect (arch) of most modern running shoes.  Then I noticed that there seems to be a link to one of the MDs leading the study and a biomedical firm which I believe is developing, or has developed, training shoes that mimic barefoot running.  After I said something like “#$*&%*!”, I did some more digging.  (PS I bother to mention the study because it seemed sound except for that possible conflict of interest) 

“There’s nothing worse than a bad foot in a great shoe.” ~Todd Durkin

                In his review of gobs of literature on barefoot versus shod running, Michael Warburton, an Australian Physiotherapist, found the most strong links between wearing running shoes and sustaining acute and chronic injuries, with the opposite outcomes occurring in barefoot runners.  Ankle sprains were found to be caused by decreasing awareness of foot position that would have been provided by feedback from the bottom of the foot in contact with the ground had shoes not been worn.   Likewise, shod runners have more trouble recovering from a stumble due to the change in leverage caused by having something like elevated heels and thick-soled shoes on their feet.   Plantar fasciitis (inflammation of the tissues on the bottom of the feet) is a common chronic issue that intuitively seems to contraindicate running barefoot.  (Or is that just me and my painful piggies that used to think that?)  In fact, the barefoot running gait may transfer much of the force of impact to surrounding musculature versus right to where the plantar fascia attaches at the heel during the heel strike dominant gait promoted by running shoes.  Indeed, it turns out that when we ambulate with naked tootsies, we land mid-foot or on the ball of the foot (not on the heel) which seems to increase the work of the foot and ankle’s support structures, thus increasing their strength, which presumably could mean a reduced risk of injury.  The barefoot landing also seems to have a markedly reduced “impact collision”.   Moreover, on some treadmill studies it was shown that wearing shoes reduced what they called “shock moderating behavior” which then caused increased impact on the feet.  In other words, with sensation decreased due to shoe-wearing, the “ouch, don’t do that” feedback from foot receptors is gone.  It would be interesting to see how that would play out on natural surfaces.  (Side note: It is not recommended for those with diminished or absent sensation in the soles of the feet to go barefoot.  Those with peripheral neuropathy, such as diabetics, are at an increased risk for infection and tissue damage without shoes.)

                Furthermore, there was another strong link between hyper-engineered (read: expensive) running shoes and increased risk of injury.  As noted above, when the shoe is doing the thinking, and, no less, thinking in a way contrary to how our unshod “hooves” would, many sensory inputs are lessened or nullified, and inherent weaknesses can develop in the foot-ankle complex which translates right up the leg and beyond, stressing joints one by one up the chain.  Researchers noted way more owies (2x more) in those runners who bought into the marketing hype and went for the spendy shoes versus their budget-conscious counterparts.  Save the money for the Manolos, ladies!  That false sense of security provided by your pricey paw-covers may be doing you wrong.  (I feel so used…)  In spite of the fact that sport training shoes now have computer chips, memory foam, roll bars, and can whip up your post-workout meal for you, common ailments such as Achilles tendonitis and Iliotibial Band (ITB) Syndrome, have not decreased since the introduction of modern sport shoes in the 1970s. 

                I didn’t find tons of stuff linking sport performance advantages to either barefoot running or shod running with regard to one being better than the other. However one study did show a 4% reduction in energy cost of running when doing it barefoot.  Another demonstrated increased oxygen consumption with running shoes, theoretically due to the weight of the shoe, and to the reduced ability of the leg to act like an energy-absorbing spring.  This was correlated further when oxygen consumption increased further with the addition of thicker shoe inserts.  In other words, without the energy return from the ground due to the shoe absorbing so much of the force, you end up working harder while wearing shoes.  Most of us have experienced this phenomenon when running on the beach (shoes or no shoes)—the sand absorbs everything and gives nothing back, leading to a grueling workout.  We could also look at it this way, being injured and/or having joint and soft tissue problems and weaknesses due to improper foot mechanics is decidedly NOT performance enhancing.  And there have been elite barefoot running champions who have been victorious over their shod competitors.  Not exactly strong support for one method over the other, per se, but at least we know that being barefoot has mechanical advantages associated with it, and that you can indeed be a champion without shoes if that is your choice.   

Freeing up your “flippers”

                Okay, so the VAST majority of what I looked at pertains to running.  That is likely because barefoot running is by far more controversial than other barefoot training.  It’s not like we don’t witness barefoot training and sports without having a moment over it.  (Examples: dance, gymnastics, martial arts.)  Even watching someone weight train without traditional fitness shoes on is quite common depending on the setting.  And when I said I’m not a fan of wearing shoes all of the time, including during training, I was mostly referring to resistance training because I’ve felt the benefits of it myself.  I have yet to try running this way. But even if you can get into the science supporting barefoot running’s more optimal foot mechanics, is it realistic for most?  In short, no.  But you know I’m going to elaborate, right? 

                “No” because most of us have faulty feet.  Were we born that way, a victim of coming into this world as a {gasp!} bipedal being?  While the shoe-making giants would have you believe that, I am of the belief that most joint issues that occur over time are a function of living in modern society where we sit way too much, walk on unnatural surfaces, and wear horrible footwear. (Is the crappy flip-flop craze over? Because that has kept me up all night for years now!).  So, in all honesty, it’s probably a good thing to wear a decent training shoe.  I know for me, the very thought of “bearing my sole” during some activities makes me wince because of my arthritis.  {shudder}  But that’s where all-or-nothing thinking keeps us from progressing.  Here’s what I mean…

                All of this post I’ve been saying “barefoot”, but, as I alluded to early on, some shoe manufacturers are on to the old skool craze of K.I.S.S. and have developed shoes that are very like being unshod.  I consider being barefoot or wearing one of these new breed of shoes to be one and the same for this post’s purposes.  Some of these shoes provide a nice alternative to completely choosing yay or nay with regard to footwear.   Most of these shoes sport much thinner soles, some to the point of being barely more than a sock.  Several have taken out the heel elevation (my favorite change from a conventional shoe, actually), and all of them are very flexible, thus allowing one’s foot to move and land as it sees fit.  The card-carrying members of Running Barefoot might call these “transition shoes”, assuming it’s not a requirement to completely shun them.  I call wearing them just plain good sense.  I mean, have you ever just looked at the ground when walking the dog, running errands, using a public toilet?  I mean SOMETHING has to protect us from all of that yuck and spit and broken shards of glass and bugs and… eeeyew…  And let’s not even get into the crusty-foot look.  Girl, at that point, the slingbacks you bought with what you saved by not buying massively-marketed sneakers just aren’t going to have the same sex appeal.  Lastly, harking back to the harder working muscles when barefootin’, start out slowly if you want to try shoeless training.  Suddenly going barefoot or barefoot-ish would be like getting up from a 20 year nap and doing a max lift followed by some EDT and finishing with a Tabata interval.  If you don’t know what that means, just imagine being so destroyed from a training session that a full body ice cast sounds heavenly.   

                What’s a girl who wants her feet to be strong, healthy functioning, independent-thinkers like herself to do?   Well, without having to relegate yourself to a sanitized treadmill and a weekly appointment at the Pedicure Palace, here are some suggestions.  Read over them while I go use my research findings to defend my “need” for some Vibram Five Fingers KSOs to my husband…

• Start simply.  Make one change: Go barefoot more often whenever safe.  Just around the house even, or also at work if you can get away with it.  (Hint: If you are self-employed, this may mean writing off pedicures.  My massage therapist and yoga/pilates teacher friends do. ) 
• If outside, in warmer temps transition to going barefoot on known-safe playing fields, turfs, and (the best!) beaches.  Just walk around, hang out.  You’ll very quickly have no doubt about how shut off our feet get from wearing shoes. 
• If you want to try out training barefoot—indoors or out—start with doing just your dynamic warm up and cool down sans shoes, then add in parts of your training if it feels right.  This is really most easily done with lifting (esp kettlebells) and bodyweight training. 
• If you start getting into it, and it’s convenient for you, you can work up to running barefoot with these tips from Warburton’s report (if you want to see what material he’s referencing here, see the “sportsci” link below in the resources section):

Adapting to Barefoot Running

Thirty minutes of daily barefoot locomotion is a recommended starting point to allow thickening of the sole of the foot and adaptation of muscles and ligaments (Robbins et al., 1993). Begin by walking barefoot at every reasonable opportunity then progress to jogging, gradually increasing the intensity and duration (Yessis 2000, p.124). After 3-4 weeks, the plantar skin eventually becomes robust and allows longer periods of barefoot running at higher average velocities (Robbins et al., 1993). To facilitate adaptation, perform progressive strengthening exercises for the foot and ankle, including foot inversion, toe flexion, and walking on the balls of the feet. Barefoot locomotion on uneven surfaces will also help stimulate the plantar surface and provide increased sensory feedback (Yessis 2000, p.125).

• If “al fresco footsies” becomes your passion, and you want to follow in the naked footsteps of Zola Budd and other champions who shunned shoe-wearing, check out www.runningbarefoot.org (these folks are serious, don’t even wear socks when you log on), or www.barefootrunner.com (informative blog)

Let’s face it, most commercial gyms are not going to let you train barefoot.  You may be able to get away with some of the like-barefoot shoes that are out now.  And we already went there about the disgusting and questionable nature of most surfaces, be they gym floors or truck stop bathrooms.  If you choose to go the sortofa-shoe-sorta-not route,  here are some brands to investigate:

• Vibram Five Fingers (most barefoot-like thing I’ve seen and worn, right down to the separate toes)
• Nike Free (most conventional looking, they do have a somewhat elevated heel, for most this might have the most efficacy as a running shoe, hubs likes these)
• Feelmax
• Terra Plana
• Earth Shoes (these are the negative heel ones, not sure about these for longer distance running, but I do like some models for walking and weight training, they have a super flex zip up model that’s fab for casual/work and easy off-on at airports!)    

Resources:

http://www.webmd.com/fitness-exercise/news/20100127/barefoot-running-laced-with-health-benefits (an easy WebMD read with another recommendation for building up to barefoot running) 

http://www.sportsci.org/jour/0103/mw.htm (Warburton)

http://www.nytimes.com/2009/08/30/business/30shoe.html (lighter article about the upsurge in barefoot running and barefoot-shoe companies) 

http://www.sciencedaily.com/releases/2010/01/100104122310.htm (article that lead me to the study below)

http://www.pmrjournal.org/article/S1934-1482(09)01367-7/abstract (the study that annoyed me when I figured out there might be a bias, still interesting especially if you have running related joint pain)