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. 

“I’ll plead the 1st … .”   More foot geek stuff from The Gait Guys.

The 1st Ray that is!

The “1st ray” consists of the 1st metatarsal and the medial cunieform, essentially the long bones associated with the big toe. It is a functional unit we often refer to when discussing foot biomechanics.

You have heard us speak of the 1st ray needing to descend to form the medial tripod of the foot (tripod review: head of 1st metatarsal, head of 5th metetarsal, center of calcaneus). This action depends to some degree on the competency of the peroneus longus, which attaches from the upper lateral fibula and the associates interosseous membrane; curves around the lateral malleolus, crosses under the foot and attaches to the base of the 1st metatarsal and medial cunieform. The tibialis posterior is supportive to this action. This action is opposed (or modulated, for every Yin there is a Yang; it’s all about balance) is the tibialis anterior, which attaches to the top of the base of the 1st metatarsal and 1st cunieform.

As a result, 1st rays can be elevated or depressed. (here is a latin term to impress your friends with: Metatarsus Primus Elevatus, or elevation/dorsiflexion of the 1st ray/metatarsal). Clinically, we see more that are elevated, resulting in a faulty (collapsing) medial tripod of the foot. The important thing is isn’t necessarily its position, but rather its flexibility. The inflexible ones (isn’t it always?) are the problem children, because they result in altered (notice I didn’t say bad) biomechanics. The further we move from ideal, the closer we seem to move to some compensation pattern. The flexible ones are still a problem but we can control and dampen their rate of flexible collapse.

Generally speaking, a plantar flexed 1st ray that is rigid, has a tendency to throw your center of gravity (an often your knee) to the outside of the foot tripod (think of a rigid cavus foot) and a dorsiflexed to the inside of the foot tripod. Sure, there are LOTS of other factors, but we are talking in generalities here.

Look carefully at the images above and note the position of the 1st metatarsal heads. In the top set, the 1st is depressed (or plantarflexed). In the bottom set they are elevated (or dorsiflexed). Cool, eh? 

NOTE: please refrain from using the term “dropped metatarsal”. Nothing gets dropped, it is correctly stated as plantarflexed (rigid or flexible).

Be on the look out for these on your clinical exam.

Ivo and Shawn. Bringing you one step closer to foot geekdom each day!

copyright 2012 The Homunculus Group/The Gait Guys. All rights reserved. If you rip off our stuff, you will be plagued with the curse of Toelio…..

Hiya Gait Guys! I have cross over gait…watched your vids on adopting new style of running (imaginary lines etc) and want to introduce the new way of running i.e. not running on a tightrope!! How quickly can I introduce this new method? I currently run 20 miles per week, generally 3-6 mile runs. I am doing some hip and glute medius strengthening at the same time. Do I introduce it a few miles at a time as I realise it will be working new muscles and how cautious should I be? Thanks

hi !

We will answer this in podcast 19

should launch this week !

thanks for your great question

The Gait Guys

Excessive Supination in a marathoner: Shoe Photos !

Simple visual case today.

Look at the right shoe, can you see how it is canted laterally? Can you see the inversion of the rear foot ?  Without a foot in that shoe it means that “the last”, the heel counter and the EVA foam are all destroyed and deformed into this great runner’s compensation pattern. 

They did not have pain however can you determine the problem here from the photos ? We hope your answer is no.  We did a teleseminar last night on www.onlineCE.com on pedograph foot mappings and we talked long and hard about the possible limitations of determining foot problems from foot pressure mappings from things like pedographs and pedobarographs.  Do you use foot scanners ? If so, user beware !  They gather vital and valuable information that you absolutely need but you need the critical clinical information from the client examination to bring the foot issue info full circle.

In this case there was a significant limitation in hip rotation. Which one ? Can you theorize ?  If you said internal rotation you are right. There was a notable loss of internal right hip rotation in his marathoner.  And it is represented in his shoe photo above. Someone who has a loss of internal hip rotation will often (but not always) have difficulties achieving the normal foot pronation required for clean foot mechanics, they will be stuck in a supination tendancy.  If loss of internal rotation can mean loss of pronation then in this case ample external rotation meant excessive supination (or at the very least rear foot inversion). Hence the shoe presentation described at the beginning of this post. (Note: this is what we would refer to as a “Flexible” Rear foot Varus posturing).

So, is this the wrong shoe prescription for this runner ? No, the shoes were prescribed correctly. This is a biomechanical breakdown of a shoe because of a hip functional problem.

Solution: Dump the shoes for a new pair and quickly restore hip function. Keeping these shoes in the mix will promote the bad pattern.  In this case, functional movement and muscle tested assessments revealed specific weakness of the right lower transverse abdominus, right internal abdominal oblique, right TFL, right vastus lateralis and coccygeal division of the g. max.   Yes, all INTERNAL HIP ROTATORS  or stabilizers or synergists of internal hip rotation.  Immediate post treatment remedy revealed near full internal hip rotation and homework was prescribed to ramp those said muscles up further to support the new movement. 

If he had remained in this shoe, the breakdown in the shoe would continue to promote the biomechanical deviations into the previously engrained faulty motor compensatory pattern. 

Shoes, sometimes they are the problem, sometimes the solution and sometimes caught somewhere in between.

Need to get better at this stuff ? Just follow us daily here on The Gait Guys or consider adding the National Shoe Fit Program to your repertoire !  Email us if you are interested or need some help with your interesting cases !

Shawn and Ivo, The Gait Guys

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