Crash Course on Running Shoes

Welcome to Running Shoe - 101.

Why you need to know this....

Generally speaking, it's advantageous to you as a consumer to understand the finer intricacies of what you are buying.  If we know what to look for, we can overcome marketing hype and scams to get what we need versus what we are told to buy.  With modern running shoes, there are many properties to consider depending on what you're used to wearing and what changes you want to make if any.  Last year I had to personally take a step back and throw away everything I learned in physical therapy school about running shoes and how to prescribe them to people.  I didn't quite realize how shaky the science behind the old prescription method was until it wasn't working for me.  That's when I began to dig deeper into the research and personally make the connection between foot health and proper footwear/lifestyle.  Many "discoveries" we make are simply old news and this is certainly the case with recognizing the damaging effects of poor footwear on the human foot.  A quick google search brings up this excellent observational study published in 1905 on shoe wear and foot health.  It's not only an amazing read but it will likely make you wonder why all of the hype surrounding running shoe prescription even exists.

When it comes to running shoes, it's important to realize that we are not told what to do, we are told what to buy.  We are told how to treat symptoms but not fix the problem.  I imagine this occurs for many reasons, not the least of which is that one solution (shoes) is easier for the consumer and allows companies a big profit.  The other solution (teaching people how to run better) is much more difficult to sell.  It means people would actually have to reconsider what they're doing and change something (their mindset, their routine, their training, their goals, etc).  One of those solutions is supported by research and it's not shoes.

Spending more on shoes does not equate to a shoe that works better for you.  This is one such study that debunks this myth.  I had a patient with raging plantar fasciitis recently visit the office.  She had paid $300 for a special pair of shoes just to try to walk without pain.  I cringed at the number of hours the average person would have to work to buy a pair of shoes that do nothing to solve the problem.  Indeed the shoes made little difference.

So what is my current practicing paradigm?
The more support, cushion, or control you think you need in a shoe, the more likely it is that you need to see a professional.

Many of us have accumulated baggage over the years from wearing improper shoes...problems such as muscle weakness, low-bone density, foot deformities, and poor running mechanics.  Not realizing you have some baggage can make any transition to a more natural foot and gait very frustrating.  Some people believe they are just changing their shoes when in reality they are actually changing the structure of their body tissues, down to the cellular level.  It's a big deal and while your body is meant to adapt to new things, it doesn't happen over night.  It takes time for your tissues to grow stronger.  The older you are, the less healthy you are, the more stress you're under, etc...the longer it will take to adapt.  It's still happening mind you, just much slower than when you were 20 years old.  So remember when you eat that healthy meal in place of a quick-fix, you are directly supporting your ability to not only recover but adapt to a higher level than you've ever been before.  Don't sell yourself short.

Now for what you need to know about shoes.

So now on to the topic I promised we would cover.  When you shoe shop you should check all of these components of the shoe for yourself.  I don't recommend basing your decisions on what a salesperson or a shoe company say about a running shoe.  I say this for multiple reasons, not the least of which is that many are still spitting out myths.  In addition, shoe companies don't follow a set criterion when they label a shoe "minimalist.  In reality, they can call any of their shoes "minimalist" if they so desire.  I have seen shoes labeled as minimalist shoes and they do not meet the basic standard - "a light-weight, flexible shoe without support that fits the human foot."  Armed with an understanding of the following shoe components, you'll be able to decide what works for you with much greater confidence.

Shoe Last: this is the mold or shape of a shoe.  My personal opinion is that the shoe last should fit the human foot (your foot specifically).  If it does not, this means your foot is molding to the shoe, which ultimately changes the way your foot can function to a degree.  A minimalist shoe should not change the way your foot functions, it should not mold your foot to fit another shape.

This is an example of a shoe last, one is shaped like the human foot while the other has been shaved down to appear more shoe-like.  Notice they aren't the same.  In general shoes are not actually shaped like the human foot and this ultimately changes the natural foot function (if the shoe inhibits the foot in any way).

Another example of a shoe last.  This is not foot healthy.

Our progression from natural feet (ideal) to what is now considered normal in our society.

Our feet should not change dramatically from the alignment you see here.

Some shoe companies have created shoes with a "natural" toe box to allow for the toes to spread and wiggle within the shoe.  This particular picture was released from the shoe company ALTRA, which makes Zero-Drop shoes with wide toe boxes.  This is an improvement to most modern shoes.  That said, most Altra shoes are still not minimalist despite these properties (I'll get to that later).

LEMS is another shoe company that makes casual shoes, boots, and athletic shoes with a wider toe box.

Stack Height: this is the overall height of your shoe.  Some companies have gone above and beyond with stack height by adding copious amounts of cushioning.  Their assumption is that more is better.  I not only question the need for such cushioning but would also point out the negative consequences of your shoe becoming the equivalent of a lazy-boy recliner.  The term midsole applies to the stuff between your foot and the rubber outer sole in direct contact with the ground.  The midsole is the cushioning component, often made of EVA, and may also have things like, "dual-density" properties or even plastics embedded within them to control pronation.

Currently all HOKA shoes carry a big stack-height.  The premise?
Running isn't inherently safe, but if you buy this shoe you will have more protection from this harmful activity.
Really???

Heel-Toe Drop: This term highlights the difference (if any) between the height of the heel of the shoe and the height of the forefoot.  High heels are an obvious example of a large heel-to-toe discrepancy.  The existence of a heel in the shoe exists only because many modern shoes have become too inflexible.  An inflexible shoe puts a stop to natural movement of the foot and ankle.  The industry's solution was to create a "rocker effect" in their shoes.  When you make the heel higher than the forefoot and when you add a "toe spring" (more on that later), it creates a rocking motion to propel you forward.  Rockers work okay for walking because walking is naturally a heel-to-toe gait pattern.  You know what isn't naturally a heel-to-toe gait pattern?  Running.

Having any heel on your shoe creates compensation at the spine to remain erect.
Without your spine compensating, you would fall forward.
All heels mis-align the spine to some degree.

Toe Spring:  this is a toe-deforming shoe feature present in most shoes, including athletic shoes. Toe spring is the elevation of your shoe's toe box above the ground or supporting surface. The current industry standard for toe spring for most types of footwear is 15 degrees.  The toe spring exists because most shoes are entirely too stiff so they're creating a rocker effect to compensate.  Other problems with toe spring are that it weakens the arches of the feet by over-stretching the intrinsic muscles.

Toe spring, like an elevated heel, is NOT natural.
Specifically, toe spring leads to toe deformities.

When toe spring became the 'norm' in our society so did these toe deformities.  Notice they are all flexion-type deformities brought on by hyper-extension of the metatarsal-phalangeal joint.  This increases the stretch on the flexors and causes them to curl the toes.  Hold that position long enough you get stuck that way!

Shoe Flexibility: In general the healthiest shoes will be extremely flexible both longitudinally and torsionally.  There are some cases when a stiffer shoe is appropriate, but it's more of a case by case basis.  Wear a stiff shoe all of the time and your foot starts to lose some of its natural spring.

"Longitudinal Stiffness" - many modern shoes are primarily flexible at the ball of the foot (some are BARELY flexible there even).  There exists podiatrists (and some ankle/foot ortho guys) who will say that if you have foot pain you should get a stiffer shoe.  While it may help in the short term by taking some stress off the foot, it's hiding a bigger problem and will cause you to compensate somewhere else in your body.  Toe spring and/or a narrow toe box (or a weak foot/chronic cushioning) is often the culprit of pain and too many simply say, "get a stiffer shoe."  No the actual answer is to get rid of the bad shoe altogether and retrain your foot to be healthy again.  You can and should always test this before buying a pair of shoes, know what you're getting and want what you get.

All Altra shoes are zero-drop (no heel) and have a foot-friendly toe box (room to wiggle),
some versions of their shoes retain the "overstiffness" of today's conventional running shoes
while some versions are more flexible.
They also make a few shoes that are maximalist cushioned which
do not fit the criterion for a minimalist shoe.
Are there conditions when a stiffer shoe is desirable?  Probably.
(could be helpful on very sharp-rocky terrain)
Should you always wear a super stiff shoe regardless of the type of run?  Probably not.
(you risk not developing normal foot spring mechanisms - see previous blogs about spring development)

"Torsional Stiffness" - represents the resistance to rotation within the length of the shoe.  Most shoes today have minimal to no torsional flexibility.  Thinking that we need a stiff shoe 24/7 is not only incorrect, it's disabling the natural foot function and health of millions of people.

This Vivobarefoot brand shoe displays excellent flexibility throughout the entire shoe,
to include rotating through the shoe (torsional flexibility).
When you wear a shoe like this you take away all restrictions to natural foot motion.
This is generally a good thing but realize your foot will need to be very strong to handle this kind of power!
Transition slowly and your foot strength will improve dramatically.

Summary of what to look for if moving away from mis-appropriated shoe technology.

The shoe on the left allows your foot to function naturally.
The shoe on the right attempts to improve upon nature and fails miserably.

What are the unintended consequences of modern conventional running shoes?

FOOT DEFORMITIES

LOSS OF MUSCLE MASS

LOSS OF LOCAL BONE DENSITY

MAL-ALIGNMENT OF FEET

LOSS OF SPRING MECHANISM

LOSS OF ARCH FUNCTION

ALTERED RUNNING GAIT

LESS EFFICIENT MOVEMENT

ALTERED BALANCE

LESS NATURAL PRONATION CONTROL

Let's talk more about that last one.  Pronation control.  Shoe companies want you to think that you need their product to "control pronation" otherwise you'll be injured.  But here are some facts on the subject; #1 - shoes do a very poor job at controlling pronation, your foot actually moves inside the shoe to some degree.  It doesn't matter what platform you hope to run upon if you're sliding over the top of it.  #2 - shoes take away your own body's ability to control pronation.  It's actually desirable for your own body to decide with each step exactly how much pronation is needed.  #3 - pronation isn't a bad thing and there is no scientific standard by which someone can measure you to say, "this is too much pronation."  #4 -  pronation will change depending on your terrain, how fast you're running, your stride length, etc.  Pronation is not a static measurement, nor should it be, it's one of many variables your body uses to react to the circumstances.  Sometimes you will over-pronate and that over-pronation may actually be protective for you.  Sometimes you will under-pronate and that was the movement which was needed for that particular step you just took.  #5 - If you cannot control your own pronation very well, putting your foot in a splint only makes the problem worse.  You had no control to begin with (you're carrying baggage from years of poor shoe choices) and now you sabotage yourself by making it impossible to improve your own foot function.  Nothing gets better with a splint (it's a last resort at best) and yet shoe companies continue to market the myth that a shoe attempting to control your pronation will make you a healthier runner.  I'll believe it when the research supports it.

You'd be better off if you just forget you ever saw this...

So how do I change doc?
Slowly, gradually, move towards wearing shoes with minimalist characteristics.  Some companies offer a line of shoes to help you transition to less shoe over time.  This is certainly one way to go.  However, armed with what you now know, you can slowly decrease supportive structures, cushioning, toe spring, and heel-drop and increase the flexibility and light-weight component of your shoes over time.  You can change one component at a time if you'd like (which like an elimination diet would allow you to see how your body reacts to one change at a time).  The more time you give your body to adapt the better.  An easy place to start is simply ensuring the shoe has a wide toe-box for your toes to wiggle freely.  After that you might start lowering your heel and wearing a shoe that has more flexibility. Down the road you may find that you don't really need all the cushioning and you only use it when you really need it.  Whatever changes you make, don't be in a rush.  Listen to your body and give your feet time to adapt.

Soreness is normal.  If your soreness improves with activity, you're on the right track.  If your soreness doesn't improve with activity, you did too much and need to transition slower.  If you have pain you definitely did too much.  Take a day or two off.  Maybe a week.  When you recover come back but slow the process down more.  Also remember that having multiple pairs of running shoes can be very helpful.  It's great to have different shoes for different terrain, distances, paces, etc.  For example, I will choose a shoe with some cushion and a bit of stiffness when running over sharp rocks.  If running on the road I choose a super thin shoe without cushioning (and on clean sidewalks or roads I can run completely barefoot).  Choose the minimum amount of shoe that YOU NEED for the task.  It isn't one size fits all and how much you need will likely change with time and training.

Merrell is an example of a company that has a range of shoes, choose one that is more minimalist than what you are used to and very gradually spend more time in your new shoes.

Do not get new shoes and simply start running in them.  If you get new running shoes, especially if they are very different than what you are used to, start with 5-10% of your run in the new shoes, then change into the old ones to finish your run.  Increase mileage 5-10% per week ONLY if you're not having pain or major soreness.  If you are, slow down the transition.  It doesn't matter that you're doing the right thing by improving your foot health, if you overdo it and transition too quickly you can easily get injured.  Each workout breaks down tissue and each recovery period you give yourself strengthens the tissue.  The process takes weeks and months to get going and years to fully manifest (you can start to feel better in a matter of weeks but your body may continue to strengthen for a very long time, 1-2 years easily).

Give it time and you will be glad you did.  GO SLOW TO GO FAST.

I'll finish this post with pictures of some of my shoes.

Former version of Altra's Lone Peak.  It's pretty minimalist except for the lack of flexibility we observed earlier.
It also has a midsole and some cushioning which I try to avoid as much as possible (unless I really need it for rock protection...possibly would use a thin midsole for ultra-marathons as well because eventually you get tired and your foot muscles may be overwhelmed.  In that situation, some cushioning makes sense)

I appreciate that Altra offers a natural toe box without toe spring or an elevated heel.
These are healthy features of running shoes.
BTW, it's not fungus on my 2nd toe, it's a bruise from dropping my huge iPhone 6 Plus on my toe.

This is the Soft Star Run Amok shoe.  The website allows you to personalize the shoe.
This is a 2-mm thick street sole and I use it for road running or easy trails.

Inside the shoe you can see there is no support or cushion.
It's leather attached to a thin rubber sole.

I ordered the WIDE version to ensure my toes had plenty of space.

This is a picture of the 2-mm thin street sole. 

Full shoe flexibility.  Unfortunately this isn't the norm in modern conventional running shoes
but that doesn't mean it shouldn't be.  You'll see that almost all of my shoes are similarly flexible.

Zem Gear makes several types of shoes, some of which are "sock-like."
This one has no cushion or support, it's just a sock-like shoe with a thin rubber sole.
I've run a 32-mile ultra in this shoe on rocky terrain.  It performed fine except for the rocks
in which case I would have preferred a slightly stiffer shoe for protection.
That said, I survived without any injuries, my feet were sore for one day and then I was fine.
So much for the HOKA theory.

 I ordered the NINJA or "split-toe" version.  If I buy another pair I will get the normal style because the separation for the big toe stretches my foot a little too much.  For some this may not be a problem.

Thin 3-mm tread

Good longitudinal flexibility

My Vivobarefoot - ideal for road running.

Fairly wide at the forefoot, although with my feet in particular I wish they were even wider.

Good tread for roads.

It doesn't get more flexible than this.

Xero shoe sandal.  This one is 2-mm thick.  I started my rehab using this sandal and going barefoot.
Notice that the "toe box" area reflects my exact foot shape.  This is a kit that
allows you to cut your own sandal to your exact foot shape.
I wish I could do this with all of my shoes.

Nice tread.  It's inexpensive to begin with but you can get a new sole
from Xero shoes if this one wears out in under 5,000 miles.

I prefer shoes I can roll up and put in my pocket.
Unless I'm on sharp rocks...then not so much.

Another Soft Star shoe.  Fits like a sock, easy on and off.
THIS IS A RUNNING SHOE believe it or not.

Personally it's a little narrow for me in the forefoot, I haven't worn them much for that reason.

Soft Star Run Amok shoe with the 4-mm trail sole for more protection.

Again got mine WIDE

Trail tread

A thicker tread somewhat decreases the flexibility of the shoe.
Still highly flexible compared to most shoes.

This was kind of a transition shoe for me, it's probably 5-6 years old now.  Note this shoe actually has a MIDSOLE with cushioning and a small toe spring/heel.

At the time it was wide enough in the forefoot for me.  However my feet have naturally widened over the past year and these shoes no longer fit me width-wise.

Still reasonably flexible despite the midsole material/thickness.

What do I like about the Vibrams?  They are truly minimalist.
What do I not like?  The toe spreading actually over-stretches my foot somewhat and creates pain after I run awhile.  Not everyone has that experience but realize this could happen and you may just need a minimalist shoe that doesn't spread your toes for you.

I ran Imogene Pass this year in this Vibram, fairly good on trails but I would avoid super rocky terrain (of the sharp rock variety).  Luna sandals would have worked much better for sharp, rocky terrain.

Still nice and flexible though.

Luna Mono sandals.  

These thick sandals actually molded to my foot overtime, they don't have a "real" toe spring.
I got them thicker for some protection on very rocky terrain

The sole.

Despite thickness, these are still quite flexible.  You will always make a trade with your shoes,
my recommendation is use the least amount of shoe possible given the terrain and your personal history.
The more shoe, the stiffer it is and the more ground feel you will lose.

As a crash course, there are likely some things I haven't covered or some questions you might have.  Feel free to leave a question and I will respond with what I know and what research I can find on the topic.  I hope this guide proves helpful to you in understanding some important components of shoes and what to look for in order to begin restoring healthy, natural foot function again.

Namaste for today!