Pete:

I wanted to make a few other comments on your post about Benno Nigg and foot orthoses.
 
I have been a fan of Benno Nigg’s work ever since I did my Biomechanics Fellowship back in 1984-85.  I even lectured with Benno and toured his lab with him in Calgary eleven years ago.  However, since Benno is not a clinician, his terminology for what he considers an “orthotic” is not the same as what most podiatrists consider to be an “orthotic”.
 
Benno, and many other biomechanics researchers, tend to include research using pads inside the shoes as being research about “orthotics”, when, in fact, a medial arch pad is very different from a custom foot orthosis. Therefore, when Benno talks about “orthotics” in his most recent book (I have all of his books in my library), you must realize that he may be talking about a simple medial arch cookie, an over-the-counter arch support that doesn’t fit the arch of the patient’s foot, or a custom foot orthosis that very closely fits the contours of the patient’s foot.  I consider this a very important distinction since, clinically, I often can take an over-the-counter foot orthosis that doesn’t work for the patient, add a few specially designed pads to it, and then make it a very effective foot orthosis for the patient.  In other words, in terms of therapeutic efficacy and biomechanical function, the three-dimensional shape and stiffness of a foot orthosis are critical.  Not all in-shoe inserts, or what many researchers consider to be “orthotics”, are the true custom foot orthoses that we prescribe for our patients.

One last comment is that, as you know, Benno Nigg’s “Preferred Motion Pathway” model is certainly something we consider when teaching the biomechanical function of foot orthoses to students and clinicians.  What is important about the Preferred Motion Pathway model is that it emphasizes the very important controlling effect of the central nervous system on determining how a foot orthosis will alter the kinematics and kinetics of an individual’s foot and lower extremity.

As far as research is concerned, we are just beginning to explore why one individual might pronate more with one orthosis while the same orthosis might supinate another individual.  My research and theoretical papers have focused on the large inter-individual variation in subtalar joint axis location being responsible for much of this varied response from foot orthoses, but there is also likely a huge central nervous system component to this response, in addition to other factors we simply don’t understand at this time.  Suffice it to say that even though custom foot orthoses work extremely well for many individuals and not so well for others, we are not scientifically certain why this is the case, even though we do have plenty of theories to explain their biomechanical effects.  The good news is that there is more foot orthosis research being done now than ever before so that, every year, we are gaining more insight into their mechanical and central nervous system effects.  It is truly an exciting time for those of us who specialize in this field of clinical research.

Cheers,

Kevin

I am not as up on the literature on orthotics, so rather than making
an uniformed statement I simply say that studies that I have read show
mixed results. Just like shoes, if they work and allow you to run pain
free, maybe best to go with it. If they don’t solve your problem,
maybe better to try a different approach. Personally, unless arches
are really extreme, I don’t think the data on arch height being
related to injury are all that compelling.

Pete

Just try it with a standard cell phone or video camera camera – it can at
least give you some idea of what you do.

Pete: 

Probably the best advice I can give to an injured runner who is possibly considering getting custom foot orthoses is to ask their runner-friends or their local running shoe store what their opinion is regarding who the best sports podiatrist is in their area.  This may, of course, mean that the injured runner may need to drive, or even fly, out of their home town to a podiatrist who treats lots of runners, but this is better than wasting their hard-earned money on a pair of foot orthoses that are either ineffective or uncomfortable.

Even though there is a significant amount of scientific research and new theories on how foot orthoses function, the actual making of an effective foot orthosis is based not only on science but is also a lot of what I call “arts and crafts”.  All of the podiatrists that I lecture with at seminars on foot orthosis therapy, and who I consider the best in the country on the subject, will have a grinder, glues, adhesive felts, sheets of EVA and other orthosis fabrication materials in their office by which to modify either their own or another clinician’s foot orthoses for patients.  I would be worried about a clinician that couldn’t modify their own orthoses, or another clinician’s orthoses, in their own office within a few minutes since I firmly believe that being able to modify foot orthoses on the spot (i.e. “arts and crafts”) is a necessary part of having a successful foot orthosis practice. 

Another complicating factor in foot orthosis therapy is that there are a huge number of permutations in orthosis design that may spell the difference between orthosis success and orthosis failure.  For example, when I teach orthosis design to podiatry students and podiatrists, here is a partial list of the various orthosis modifications that may affect foot orthosis comfort and function:

-Negative casting type
-Foot joint position during negative casting
-Frontal plane balancing position of positive cast
-Medial heel skive or lateral heel skive thickness
-Medial expansion plaster thickness
-Plantar fascial accommodation thickness
-Orthosis plate material
-Orthosis plate thickness
-Rearfoot post material
-Rearfoot post angle and motion
-Heel contact point thickness (i.e. heel lift)
-Anterior orthosis edge length, shape and thickness
-Metatarsal pad size, shape and location on orthosis plate
-Topcover material
-Topcover length
-Forefoot extension material
-Pattern, thickness and shape of forefoot extension material
-Medial and/or lateral longitudinal arch filler material and thickness

The subject of orthosis design, orthosis function and the body’s response to different orthosis designs comprise much of the academic material that I have published in my scientific papers, I have written in my books and have taught in my lectures over the past quarter century.  By its nature, it is a very complex subject.  Suffice it to say, that there are probably tens of billions of foot orthosis design permutations if you factor in all the materials, shapes, thicknesses and angles that a foot orthosis can be made, with only a fraction of these orthosis design permutations being able to be worn daily by the runner, make them run with less injury and with more comfort.  Luckily, the human body is quite adaptable so that orthosis imperfections do not always translate into problems for my patients, with some individuals being quite like the “princess and the pea”, feeling every little surface imperfection, with other individuals being more tolerant of imperfections in their shoes, their socks and their foot orthoses. 

Hopefully, I have been able to at least partially answer your question.  I could go on and on since this is a fascinating subject for me and is a subject I have spent most of my adult life researching, thinking about, writing about and teaching.  For those of you who want to learn more about both over-the-counter foot orthoses and custom foot orthoses, you may want to check out some of the excellent discussions we have had over the years (in the archives) on Podiatry Arena at http://www.podiatry-arena.com.   

Sincerely, 

Kevin A. Kirby, DPM

Could it be the reduced (because of the shoe) and consistent ground feel of concrete plays a role in our strike in a minimalist shoe?

 very good point, when running barefoot over an uneven terrain or where there are lots of objects (pincones/acorns in my case) on the ground I tend to shorten my stride even more and reach more with the forefoot. On an lang stetch of bare dirt ill revert to a much less forefoot strike.

Still put me in my Ronin’s and a race on concrete and im heel striking like a champion (or not as most dont seem too)… Im not ready to go to a lower heel toe drop just yet. probably with the next shoes i get.

Paul:

There are many varieties and styles of custom foot orthoses that are used to treat running injuries.  These custom foot orthoses (i.e. orthotics) can be made with thousands of design permutations in order to accomplish the goals of foot orthosis therapy.  Therefore, one must first understand that custom foot orthoses can have a wide range of shapes, lengths, widths,  stiffnesses, thicknesses, cushioning and ability to control or encourage certain foot and lower extremity motions that 1) will decrease the stress on the injured structure(s) of the runner’s body, 2) will optimize their running gait, and 3)  will not cause other new problems to occur.

Most sports podiatrists try to design their running orthoses based on the patient’s weight, foot type, running style, individual biomechanics and specific foot and/or lower extremity injury, to name a few factors.  We also try to “tune” the orthosis/shoe combination in order to get the runner back on the road as soon as possible with the best results and with the least chance of injury in the future.  This may include getting the runner into a lighter weight less controlling shoe, into a heavier weight more controlling shoe, into a minimalist shoe, etc.

The scientific research on the foot orthoses in running supports the principle that foot orthoses perform their therapeutic effects by altering the kinematics (i.e. motion patterns) and the kinetics (i.e. forces and moments) of running gait.  Foot orthoses are designed to facilitate normal motion and normal forces/momentsand to eliminate abnormal motion and abnormal forces/moments.  They can certainly be used along with “minimalist shoes” and, if designed correctly, can be used in practically any running shoe.

By the way, Paul, you seem to suggest that “big cushioned running shoes”, (whatever that means) promote “an unnatural gait”.  Do you have any scientific evidence of that?  I would be very interested if you could point me toward any scientific research that supports the interesting notion that cushioned running shoes cause an “unnatural gait”  since, as far as I know, there is no research that comes close to supporting that idea.

Kevin A. Kirby, DPM
Adjunct Associate Professor
Department of Applied Biomechanics
California School of Podiatric Medicine

I think you have a useful datapoint in understanding what drives the transition between landing types.  I also agree that ground feel as well as heel drop is an important role in pushing us to one landing type or another.My guess is that you aren’t yet a habitual midfoot/forefoot runners so when you revert to landing type it’s heel strike when it can.  Think of the heel strike as your default that you’ll return unless a sufficient stimulus is applied.What happens when you run barefoot on concrete?  My guess is that this will provide a bit more stimulus to the nerve ending in your heel to push you over to landing on your midfoot/forefoot.My own experience is that I still have to consciously land on my midfoot when running in more cushioned and shoes with a heel drop greater than 6mm, but now anything less than this will midfoot strike on all surfaces without thinking about it.  I put this down to the amount of plantar flexion on landing becoming habitualized, that I no longer need a strong stimulus to change my landing type.  I don’t know how long you’ve been transititioning, but I’ve been flirting with midfoot strike for two years now but only seriously running with minimal shoes for the last six months. It’s only in the last six months that I think I’ve started become a habitual midfoot runner – landing on my heel now feels forced and unnatural.

Pete:

I don’t know what you mean by the “competition store”.  Of course, being here in Sacramento, with lots of runners like myself, and with the original Fleet Feet store starting here on J Street 35 years ago, maybe my view or definition of a running specialty store is different from yours.  I also sold running shoes at two different running shoe stores in San Francisco while I was a podiatry student (1979-1983) and I clearly remember racing flats, what you now call “minimalist shoes”, being on the shelves for runners to purchase if they wanted to.  I know because I sold them to runners back 30 years ago.  If the runner wanted the shoe, there were absolutely no restrictions from them buying them.  So, maybe in your neck of the woods, “minimalist shoes” have only been available for 5 years, but in my neck of the woods, they have been available for decades.

I do agree with you, however, that having the “minimalist shoe” option can be a good thing for some runners and that it should be made more accessible to runners.  However, I also see lots of runners jumping on the “minimalist shoe bandwagon” and getting injured doing so.  And this is despite any controlled trials looking at the efficacy of “minimalist shoes” preventing injuries.

And the reason I brought up the racing shoe history is that Marty made it sound like wearing racing flats with thin heels was something new or special or unique.  We were all doing it in the 70’s and 80’s when I was in peak racing form. Therefore, I do believe that the argument needs to be made that runners have been wearing thin soled shoes to race in and train in for decades and that to suggest that this interest in “minimalist shoes” is something new, to me, sounds like people are trying to create something that sounds new, when, in fact, it is an old idea, with a new name: analogous to instead of “used cars” we now call the same items,  “pre-owned cars”.

Cheers,

Kevin

Hi Kevin,

Your explanation of a little of the ins-and-out of custom orthothotics struck me that this personalised approach is something that shouldn’t really be limited to just othotics.  Personally I’d love to have an world where everyones
shoes can be tailored from the ground up for them.  

Roll back a hundred years and many people who could afford shoes had them made for them by a cobbler.  Mass manufacture has taken us long way from this.  From your description a skilled podaristist is adding back in the personalized tailoring.

I have an engineering and computing background so can’t help but wonder if technology combined with a little local craft skill might be able to bring personallized shoe manufacture to all.  Do you know if inserts ever been manufactured using 3D printing?

Robert.