Too much pressure for the holidays? Take a look at that midsole of yours…

In the vein of last weeks post on plantar pressures, we find that midsoles DO DECREASE plantar pressures, especially across the midfoot (30% less pressure in this study), again dependent on foot type (In this study, low vs high arched individuals). They also INCREASE plantar contact area. Contact area can be useful for helping to influence biomechanics of different foot types (often more contact area = more force attenuation)

We also saw that they increase pressures LATERALLY (see our post here).

Bottom line? You need to look at foot type and remember that “shoes are medicine”. Watch what you are prescribing and think about what you are trying to accomplish. There is no substitute for good biomechanics.

We are The Gait Guys. Bringing you the best of gait, each week.

Shoe Types and plantar pressures

J Am Podiatr Med Assoc. 2009 Jul-Aug;99(4):330-8. Effect of running shoe type on the distribution and magnitude of plantar pressures in individuals with low- or high-arched feet. Molloy JM, Christie DS, Teyhen DS, Yeykal NS, Tragord BS, Neal MS, Nelson ES, McPoil T. Source US Army-Baylor University Doctoral Program in Physical Therapy, Ft Sam Houston, TX 78234-6138, USA. Joseph.Molloy@amedd.army.mil

Abstract BACKGROUND:

Research addressing the effect of running shoe type on the low- or high-arched foot during gait is limited. We sought 1) to analyze mean plantar pressure and mean contact area differences between low- and high-arched feet across three test conditions, 2) to determine which regions of the foot (rearfoot, midfoot, and forefoot) contributed to potential differences in mean plantar pressure and mean contact area, and 3) to determine the association between the static arch height index and the dynamic modified arch index.

METHODS:

Plantar pressure distributions for 75 participants (40 low arched and 35 high arched) were analyzed across three conditions (nonshod, motion control running shoes, and cushioning running shoes) during treadmill walking.

RESULTS:

In the motion control and cushioning shoe conditions, mean plantar contact area increased in the midfoot (28% for low arched and 68% for high arched), whereas mean plantar pressure decreased by approximately 30% relative to the nonshod condition. There was moderate to good negative correlation between the arch height index and the modified arch index.

CONCLUSIONS:

Cushioning and motion control running shoes tend to increase midfoot mean plantar contact area while decreasing mean plantar pressure across the low- or high-arched foot.

all material copyright 2012  The Gait Guys/ The Homunculus Group. Please ask before using our stuff or Santa will bring you athletes foot this holiday season. 

Podcast #18: Treadmills, ‘Shrooms & Santa

If you do not split a gut laughing by the time the band plays there is something wrong with you ! Who says gait stuff isn’t entertaining !
Perhaps our best podcast to date ? You decide.

Permalink URL
http://thegaitguys.libsyn.com/pod-18-treadmills-shrooms-santa

itunes link:

https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138

Topics: Treadmills, neuroreceptors, foot types, hip biomechanixcs, gait cycle

Neuroscience piece link:

http://www.cannabisculture.com/articles/3136.html

1. from Eric on our FB page:

a. Had a 9yr old girl for a shoe fitting recently. She had a forefoot valgus, with a rearfoot that is neutral or slightly varus. Fairly high arch and rigid Midfoot for a child that age as well. usually a child’s foot is super flexible so this makes me wonder if it’s a compensation for a true FF varus. How do I tell if he has an anatomic FF valgus vs a compensated version?

b. I asked Blaise Dubois his opinion on Treadmill vs outdoor running and he mentioned that the literature indicates TM’s aren’t much different than outdoor. He cites (Wank 1998). To me, running feels completely different and I can’t run nearly as efficiently on a TM as outdoor. i know some people are the opposite, which i subscribe to specificity of training.

the question i have is what basis do you use for your opinion on different motor patterns? i agree with you, but the literature seems to disagree. this is a piece from cybex so of course it will be “pro-treadmill”, but they quote several studies that concur with Wank… http://media.cybexintl.com/cybexinstitute/research/Truth_on_Fit_Apr10.pdf

hope i’m not sending too many questions. i figure you can ignore them if you have too many from other listeners.

http://media.cybexintl.com/cybexinstitute/research/Truth_on_Fit_Apr10.pdf
media.cybexintl.com
2. On the Hip Bio Pt 6 you mention ext rot leg to gain leg length.  This one has been racking my brain.  I could see how this could happen if the person supinates the foot at the same time, but is there some other external rotating mechanism occurring in the hip that would cause this lengthening?  Thanks,Ryan

___________

Hi Gait Guys,

I am a chiropractor in South Africa, and find gait, biomechanics and running fascinating…I’m hoping to become a true gait geek one day.Reading your blog has taught me so much, you guys seem to look at gait from every angle and don’t take things at face value.

I would like to find out about your Shoe Fit Certification Program. Can people from outside the USA complete the course? Would I be able to take the exam online? and would it give me any creditation in South Africa

 Hope to hear from you soon.

 Regards, Claire

3. I have been watching your video’s on you tube.  I have a cavus foot in which I have had severe nerve pain, why is the high arch caused by nerve pain?

And would any of your exercises help with my nerve pain

Thanks,Wendy

___________
4. Hi guys,
Found your youtube channel. Very interesting stuff. Have started reading up on the whole gait cycle. Its very interesting.
I have a quick question that I hope that you can help me with:
Are you aware of any correlation of hip impingement (cam/pincer) in terms of having an irregular gait cycle?
I am suffering from both CAM & PINCER impingement in my right hip. Had surgery in January, but they did not shave sufficiently off the bone, so going back to surgery soon.
I am therefore interested in seeing how surgery possible could help me with bettering my walk and strain on my lower back / leg / foot. And also in terms of looking into some theory on how to retrain myself in walking cycles.
The problem is, that this kind of rehab/research is not available here in Denmark. So would appreciate if you are aware of any research on the above, and would be able to point me in the direction of that.
Thank you – and keep those great videos coming. 🙂
Best,
Terje (Denmark)

Shoe News You can Use…

The Heel Counter– the back of the upper

This is the back of the shoe that offers structure (just squeeze the back of a shoe. this is the rigid part you feel between your thumb and 1st finger, unless of course, you are using your teeth). This is often part of or integrated with the upper.

A strong, deep heel counter with medial and lateral support is important for motion control; It offers something for the calcaneus (heel bone) to bump up against when as it is everting (moving laterally) during pronation. Look at folks that have a bump on the outside of their heel (particularly the ladies(sorry, true); this is often called a “pump bump”). Now look at the inside of their shoes. See that worn away area on the inside of the back of the shoe? Now you know where that worn away area is coming from!

Lateral support especially for people who invert a great deal or when you’re going to place an orthotic in the shoe which inverts the foot a great deal.  The lateral counter provides the foot (or orthotic) something to give resistance against.  The lateral counter needs to extend at least to the base of the fifth metatarsal, otherwise it can affect the foot during propulsion. A deep heel pocket in the shoe helps to limit the motion of the calcaneus and will also allow space for an orthotic. The heel counter should also grip right above the calcaneus, hugging the Achilles tendon.

We know you want to know more. We can help. Take the National Shoe Fit Certification Program. If you like, sit for the exam and get certified as well. Email us for details thegaitguys@gmail.com

The Gait Guys. We’re your heel counter!


all material copyright 2012 The Homunculus Group/ The Gait Guys. All rights reserved. If you want to use our stuff, please ask. If not, Captain Cunieform may pay you a visit…

Are old running shoes detrimental to your feet? Here is some research.

Are old running shoes detrimental to your feet? A pedobarographic study.

by: Rethnam U, Makwana N.

STUDY BACKGROUND: “Footwear characteristics have been implicated in fatigue and foot pain. The recommended time for changing running shoes is every 500 miles. The aim of our study was to assess and compare plantar peak pressures and pressure time integrals in new and old running shoes.”

CONCLUSION:

“Plantar pressure measurements in general were higher in NEW running shoes. This could be due to the lack of flexibility in new running shoes. The risk of injury to the foot and ankle would appear to be higher if running shoes are changed frequently. We recommend breaking into new running shoes slowly using them for mild physical activity.”

What do The Gait Guys say ? Did you read our post yesterday on this very topic ? Here is the link.  Never let a pair of shoes get too old before breaking in a new pair. The old shoes can be just as much of a problem as the new shoes.  Old shoes break down the foam into possible detrimental biomechanical patterns that can promote overstress to areas and create injury. A new shoe can be stiffer and thus change your biomechanics away from what is clean function for you.

So what is the solution ? If you read our blog post yesterday you know the answer (see #5 in yesterday’s blog post). LINK  (Blog post December 5th, 2012).

Shawn and Ivo, The Gait Guys

BMC Res Notes. 2011 Aug 24;4:307.

Are old running shoes detrimental to your feet? A pedobarographic study.

Source

Department of Orthopaedics, Glan Clwyd Hospital, Rhyl, UK. ulfinr@yahoo.com.

http://www.ncbi.nlm.nih.gov/pubmed/21864342

The Great Myth of Rotating your Shoes : Here are the Actual Facts as we see them.

Everyone has heard the rules, rotate into new shoes about every 400-500 miles.  We disagree, kind of, and we have talked about it on previous blog posts in the past and on our podcasts.  Many shoe reps have agreed with the methods we employ for our runners.

The EVA foam often used in shoe manufacturing has a lifespan, or better put, a given number of compression and shear cycles. It can go through a rather fixed number of compression cycles before it loses its original structural properties, the older the foam gets the faster the degradation process and the more risks it poses for runners.  It is known that EVA foam compressed into a focal vector or area over and over again becomes softer and more giving into that vector/area over time.  Hence, if you have a compensation pattern or a known foot type (forefoot varus, forefoot valgus, rearfoot varus, rearfoot valgus or a combination of these 4) you will break down a certain region or zone of the shoe’s EVA foam. For example a forefoot varus foot type will often drive some heavy focal compression into the foam under the first metatarsal. However, if you combine it with a rear foot valgus it will drive shear forces and compression into the  EVA foam along the entire medial aspect of the shoe (see the 2 pictures attached, you can see the evidence of excessive medial compression and medial shear in a foot that has severe rearfoot valgus and forefoot varus. This is a very poor shoe prescription for the foot type involved).

Here is what you need to do / know:

1- Know your athletes foot type so you can make more informed decisions.

2- Know the type of foam of the shoes you are recommending (ie. Altra uses A-Bound foam instead of EVA just as an example. A-Bound is an environmentally friendly energy-return compound is made of recycled materials. It reduces the impact of hard surfaces while still maintaining ground feedback. Traditional running shoe foam compresses 70-90% while A-Bound™ compresses 2-3x less so it won’t deform over time.).  Cheap shoes use cheap materials.  Altra goes the extra mile for foam quality and many others are beginning to follow suit. If you think you are getting a deal on shoes, know what “the deal” is, it just may be cheaper materials.

3-  500 miles is not the rule for everyone and every shoe.  If you have a relatively neutral forefoot and you are a forefoot or midfoot strike runner you will get far more miles out of a shoe.  If you depend on a stability shoe with dual densities of foam to slow your pronation and control your medial foot because of a rearfoot valgus and/or forefoot varus know that the shoe’s foam will break down less uniformly because of foam interface junctions and whatnot.  This is a science. Engineers call it “the mechanics of material deformation”.  We wonder how many mechanical engineers shoe companies have on board in their R&D divisions ?  We know for a fact that a few do not. There was a reason we snuck quietly into the mechanical engineering departments of our Alma Mater and sat quietly in the “Materials” classes. At the time our roommates just told us it was  cool class, little did we know why it was so interesting to us, until now.

4- Here is what we recommend. Fit the foot type to the right shoe selection. If you are weak in this territory consider taking our intense “National Shoe Fit” program. Fit is everything. Make the wrong choice for your client and the shoes will break down quicker and into poor and risky patterns. Make the right choice and be their hero. If you are looking for a way to improve clientele happiness and store loyalty our Shoe Fit Program is the way. Just read the testimonials here on our blog. Some of the top stores in the Nation have quietly taken the National Shoe Fit Program from us, they have good reason to. They also have good reason to keep it quiet, to get the edge on the competition.

You can email us to get this information and the e-file program download. Why not certify your entire store staff ?

Email us at   thegaitguys@gmail.com.  This program will teach you foot anatomy, functional anatomy, shoe anatomy, foot types and matching foot type to shoe type as well as many other aspects of gait and lower limb biomechanics.

* 5- Try this recommendation.  At 250 miles buy a new shoe to accompany your shoe that already has 250 miles. Now you are rotating 2 shoes. From this 250 mile point moving forward, alternate the newer show with the older shoe. This way you are never in a shoe that is notably more deformed in a specific area of the EVA foam because of your compensations, limitations or foot type. Essentially you are always just a day away from a newer shoe that has less driving force into abnormally compressed EVA foam.  The older the shoe gets the more it accelerates your foot and body into that deformation and hence why many injuries occur as their shoes get older. Continue to alternate shoes on every other run (new, old, new, old).  Once you hit 400-500 miles on the old shoes, ditch them and get a new pair again to restore the cycle once again.  In fact, to be specific here is what we recommend. Monday, old shoe. Tuesday, new shoe. Wednesday do not run, rather, rest or cross train. Thursday go back to the older shoe. Friday new shoe and repeat. This way you are 4 days between runs in the older more deformed shoe. The one day off running in mid week gives tissues that were challenged by the “old shoe run” a bit more time to repair.

6- Dedicate your shoes to running only. Running gait is not the same as walking gait. Why would you want to break down the EVA foam at the rear foot during walking (because heel strike is normal in walking) when in running you are a mid-forefoot striker ?  Keep walking shoes for walking, running shoes for running. Otherwise you are just asking for trouble.

Check out our National Shoe Fit program and certification process here as well as links to our other teaching DVD’s & e-downloads:
 http://store.payloadz.com/results/results.asp?m=80204

Shawn and Ivo. Helping you use your head (and shoe knowledge) better everyday.
The Gait Guys  (have you checked out our RebelMouse page ? https://www.rebelmouse.com/TheGaitGuys/

Keeping up with our awesome informative podcasts ? It is all free stuff ! https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138

How about our youtube channel ? http://www.youtube.com/user/thegaitguys

How about our Facebook PAGE ?  https://www.facebook.com/pages/The-Gait-Guys/169366033103080

Gait Forensics: Why the government and their cameras will get it right

On Podcast 17 (click here for a link to our iTunes account) we mentioned and shared a brief snippet from a recent Nova Now (video.pbs.org) entitled “How the Brain Works”. In this podcast we discuss astrophysicist extraordinaire Neil DeGrasse Tyson’s thoughts on how vision can fool us because of 2 basic types of neuroreceptors, one that detects motion while the other suppresses the background. This occurs when we are tracking an object in something called smooth pursuit.  In other words, the brain doesn’t pay attention to everything our eyes look at.  The brain just cannot process all of the visual information accurately. This is a handicap as a human. It is what can make us good at some aspects of vision and less good at others, the question is “Can this be taught and refined ?”  Great basketball players for example can see the the entire court and see plays developing. Wayne Gretzky was also reportedly great at this. This is what led him to say “I skate to where the puck is going to be, not where the puck currently is.”  Watch any youth soccer  game and you will see just the opposite. You will see a hoard of little arms and legs all huddled around the soccer ball, no play is developing rather they are all in the moment competing to get the soccer ball.

Why are we talking about this from this perspective ?  Well there have been continued developments in the government’s gait recognition software, something we refer to as “Gait Forensics”.  Here are 2 links.

1. http://www.dnaindia.com/scitech/report_now-cameras-can-identify-thieves-from-their-walk_1743650

2. http://rt.com/news/identify-walk-system-britain-668/

Computers will likely have the advantage of gathering all of the info on a persons gait. It will not get caught up on the face or the clothes, there will be no discrimination. The software will likely capture head carriage, arm swing, stride length, step length, cadence, postural characteristics and so much more.  It will be more information than the human will likely be able to process because computers will not likely suppress any aspects of a persons gait like we mentioned in the opening paragraphs of this blog piece. To the computer, all  parameters will have equal and top priority, at least in gathering information.  Interpretation remains another matter. But we are most sure that in time that too will be ironed out.

Shawn and Ivo

More to say about the National Shoe Fit Certification Program…
“I found the course to be the perfect blend between science and retail practices, making it an essential tool for any specialty running store. Immediately after finishing the video I was able to recognize specific issues in my customer’s feet and their reaction to my knowledge couldn’t have been more positive. As a result of becoming certified I will have happier and healthier customers and will know when to refer particular foot and gait issues to my partner doctors and physical therapists. The video will be a resource long after becoming certified.”

Ben Nelson is the manager of Goldstream Running, the farthest north run specialty shop in North America (and maybe the world!), located in the Goldstream Valley outside of Fairbanks, Alaska. He also coaches high school cross country and track and field.

Want to know more about getting certified? drop us an email: thegaitguys@gmail.com