September 22, 2014

Every good story has a villain, our Blog story’s villain is this man. Do you know who he is?

He is John Smeaton, who lived

in 18th century in England.  He was the first self-proclaimed civil engineer, and often regarded as the “father of civil engineering”. He was important in the development of modern cement, because he identified the compositional requirements needed to obtain “hydraulicity” in lime; his work which led ultimately to the invention of Portland cement. Portland cement led to the re-emergence of concrete.  Cement is a good thing right? Not for your feet.

By the 18th century modern man knew that the world was round, but that didn’t stop John Smeaton, he made the world flat again! Think about a day in the life for your feet in this modern flat and hard world.  Your first step out of bed is on to a flat surface (assuming you clean your room), when you leave your flat surfaced house in the morning you walk outside on to cement and asphalt to your car.  Your place of employment is most likely built on a cement slab.  It may seem counterintuitive, but standing on a hard flat surface all day maybe the worst thing you can do to your feet.  Your feet are meant to be mobile adaptors to the ground.  Think of primitive human’s fist walking the savanna, adapting every step.  Human’s feet developed this way for thousands of years and became adaptive and incredibly efficient.

Ancient man’s feet where stronger, and wider then modern man’s feet when we compare fossilized artifacts.  We can also assume that ancient man’s feet were more mobile than ours as well.  Constantly walking on uneven surfaces would naturally mobilize all of the 31 different joints in the human foot.  All of this foot movement was also good for the nervous system. The human foot is the second most sensitive area in your body. There are thousands of nerve endings in the foot that detect the slightest change in the ground surface and send that information to the brain. (The next time you need to act in self-defense, it is actually much more debilitating to stomp on someone’s foot).The ground we walk on today does not challenge the muscles, ligaments, joints, or nerves of the foot. The old saying goes “use it or lose it”; this definitely applies to our feet.  The joints stiffen, the muscles shorten from inactivity and become weak, and our brain doesn’t get the sensory information it needs to coordinate our foot movements. What is even worse is that over the last 30-40 years, we have started housing our feet in little day spas called athletic shoes.  The EVO foam within shoes dampens the sensory input into our feet even more. The trend has also been to add more motion control to shoes, again limiting the foot’s natural ability to move. This ongoing cycle of foot weaknesses and under-stimulation may have caused the recent wave of minimalist shoes to hit the market the last few years.

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Minimalist Shoe RevolutionNow the running and fitness word is in the start of the minimalist shoe revolution.  A Blogger defines the three criteria for
the perfect minimalist shoe:
1) Allows for maximum proprioception for the intended purpose. The purpose defines the trade-offs necessary for thermal and puncture protection.
2) Allows for appropriate shifts in the body’s center of gravity in terms of sole thickness and heel to toe differential.
3) Allows for complete natural movement of the foot in terms of room and flexibility for bone structure and elasticity as well as proper heat dissipation.
Philosophically, minimalist shoes are a great idea if you lived your life on an Amish farm inthe middle of Pennsylvania your whole life. But, most of us have lived our whole lives in athletic shoes walking and exercising in a hard flat world of cement and concrete.  We have been literally trained to live in shoes, and our foot morphology has changed. The good news is, your feet can change back, but it takes time.  Going cold turkey never works, a runner needs a plan before starting to wearing minimalist shoes.

Potential Injuries

If someone makes too dramatic of a change to minimalist shoe or barefoot, several injuries can occur. The most common complaints of runner who switches to minimalist shoes are plantar fasciitis and Achilles tendon injuries.  Both of the mechanisms related to these injuries are due to overloading of tissues that may have been shortened due to years of running with an elevated heal. Typically, minimalist footwear have close to a zero drop, meaning when standing flat on the ground there is the same height difference from the ball of your foot to the ground as there is from the heel of your foot. The extra few millimeters that the heel must travel to hit the ground may not seemlike much in a zero drop shoe.  But, repetitively making the tissues of the plantar fascia and Achilles tendon stretch thousands of times during a simple 3-5 mile jog can easily lead to an injury.   Not as common, but very serious injury associated with minimalist running are tribal stress fractures.  Military research discovered that soldiers with high supinated arches are more likely to have a stress fractures marching while in basic training. Like the military study, switching to a midfoot landing is much like mechanics of marching; therefor the risk of stress fractures might be the same in someone with a ridged foot. It is my belief that when a runner switches to a minimalist shoe, often their running technique changes. Like learning any new skill, you will have flaws in your gait pattern initially.  The problem with minimalist shoes is that if you are running on hard surfaces, there is no room for error with a minimalist shoe because of its lack of built in shock absorption and fractures may happen. Another potential problem with running in minimalist shoe is discussed in Dr. Thomas Michaud’s book Human Locomotion.  Permanent injury may occur to a runners heel pad by running on cement/asphalt barefoot or with a minimalist shoe, especially when still using a heel strike. Unfortunately, if you damage the fat pad in your heel, it may never heal and can lead to chronic pain.

Minimalist Shoe Transition RecommendationsMy recommendation for switching to minimalist shoe is building in a large transition zone to prevent injury and give your body and feet a time to adapt.  Before someone goes out a buys a minimalist shoe, I would consult an expert in the field of gait and sports medicine, like myself (shameless self-promotion warning).  A proper biomechanical evaluation should be performed to see if switching shoes is appropriate for you.  Individuals may need to preform exercises and stretches prior to even attempting the switch to minimalist shoes.  To begin the transition to minimalist shoes, an individual should start by wearing the minimalist shoes around their house for a week, prior to running.  The first few weeks of running in the minimalist shoes should be performed by alternating running days in traditional shoes and the new minimalist shoes.  Distances should build very gradually with minimalist shoes. It may take several weeks to run three miles in a minimalist shoe even if you are used to ten mile runs in traditional shoes.  Training on softer surfaces like dirt or grass can also degrees the new stresses associated with minimalist shoe running.  Another smart idea when switching to minimalist shoes is not jumping in to a shoe like an aggressive Vibrum Five Finger first.  They have started to sell hybrid models that give your body more time to adapt to the gait changes and mechanical changes associated with minimalist shoed running.  If you continue to plan to do the majority of your running on hard surfaces, invest in a hybrid shoe( like a Saucony Kinvara) for your long run days and then wear a true minimalist shoe for the light training days.

Minimalist Shoe Gait Changes

There are a few typical changes in gait mechanics observed in gait mechanics when a person starts to run and train in minimalist shoes.  First and the most significant change noticed is in the contact zone of the foot on initial foot strike.  Whereas traditional running shoes with a high heel and a positive drop, cause runners to inherently contact the ground with their heel first. (This heal contact will be addressed in future blog posts.) Wearing a minimalist usually leads to a midfoot or forefoot strike.  Minimalist shoed runners also have a higher cadence in running.  An average recreational runner may have a cadence of 120 steps a minute; by switching to a minimalist shoe a runner’s cadence may increase to 150-160 steps a minute.  This increase in cadence is caused by three factors.  First, minimalist runners shorten their stride length, or more importantly they don’t over stride.  Second, minimalist shoe runners decrease their vertical elevation while running (decreasing ground reaction forces). Lastly, minimalist runner’s shoes are much lighter than even the lightest traditional running shoe.

The proven benefits to running in a minimalist shoe are: smoother ground impacts, maximum shoe and foot flexibility, increased traction, increased sensory input in your foot (proprioception), increased toe function, and finally it gives the runner more of a chance to self-analyze and “feel” their running gait mechanics.  Because the protective shock absorption is gone from the traditional running shoe, the minimalist shoe runner really feels every step (proprioception).  Subconsciously, the runner will intuitively find ways to reduce the stress of running by changing their gait mechanics.

I think it is important to note that shoes are just tools.  Man’s ability to use tools has set our species apart for the rest of the animal kingdom. But, our use of tools is not without mistakes and failures along the way.  Ideally, everyone should be able to put on a minimalist shoe and run a 5k and feel great.  Unfortunately, that’s not possible because our bodies have adapted to our surroundings. We are used to wearing traditional running shoes and our running and daily walking surfaces are hard and flat. This is not the minimalist shoes fault, but it is an undeniable truth we must accept.

Per Dr. Feils guide to minimalist shoes.