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Things may not always be how they appear.

What can you notice about all these kids that you may not have noticed before?

Look north for a moment. What do you notice about all the kids with a head tilt? We are talking about girl in pink on viewers left, gentleman in red 2nd from left, blue shirt all the way on viewers right. Notice how the posture of the 2 on the left are very similar and the one on the right is the mirror image?

What can be said about the rest of their body posture? Can you see how the body is trying to move so that the eyes can be parallel with the horizon? This is part of a vestibulo cerebellar reflex. The system is designed to try and keep the eyes parallel with the horizon. The semicircular canals (see above), located medial to your ears, sense linear and angular acceleration. These structures feed head position information to the cerebellum which then forwards it to the vestibular nucleii, which sends messages down the vestibulo spinal tract and up the medial longitudinal fasiculus to adjust the body position and eye position accordingly. 

Can you see how when we add another parameter to the postural position (in this case, running; yes, it may be staged, but the reflex persists despite that. Neurology does not lie), that there can be a compensation that you may not have expected?

What if one of these 3 (or all three) kids had neck pain. Can you see how it may not be coming from the neck. What do you think happens with cortical (re)mapping over many years of a compensation like this? Hmmm. Makes you think, eh?

Ivo and Shawn. The Gait Guys. Taking you a little further down the rabbit hole, each and every post.

The turned out foot. How far ahead (and how fast) can you think ? 
There are many causes of the turned out foot. The above slide is just one of many logical and possible chain of events.  
There are also reasons above the neck that cannot be ignored…

The turned out foot. How far ahead (and how fast) can you think ? 

There are many causes of the turned out foot. The above slide is just one of many logical and possible chain of events.  

There are also reasons above the neck that cannot be ignored in creating the externally rotated foot (and in resolving it). Things are not always biomechanical in origin so remember this when you are continually doing activation and rehab interventions to get more glute or drive more internal limb spin and your results are met with a non-response.  

Most of us like a biomechanical line of thinking when it comes to apparent biomechanical aberrancies from the norm.  However, more often than you probably think (go back and listen to podcast 58 on Cortical Brain Mapping of injuries), several more purely neurologic reasons are plausible.  For example, changes in input/output in unilateral activity within the pontomedullary reticular formation (PMRF) of the brain can lead to inhibition of the posterior chain muscles below the T6 spinal level (And anterior muscles above T6. And what is awesome is that there are ways to test this kinda stuff on a physical exam !  However, this blog post is not the place to teach these neurologic examination procedures.  But, if this sounds like Janda’s Upper and Lower Crossed Syndromes you are thinking soundly. Just remember though, if you are fixing what you see, you may not be fixing the problem, fix the cause that drove what you are seeing.  If you know your functional neurology you will know where these things come from, they are a cortical phenomenon).  

Of the posterior compartment muscles below T6, the gluteus maximus is probably the largest of this group and when it is inhibited there is loss of control of its ability to stabilize single leg stance.  One strategy around a stability challenge would be to turn the foot/leg into the frontal plane (toe out) via external limb rotation.  Now we can use the remaining muscles in both the sagittal and frontal planes ! We are always more stable when we can engage two or more cardinal planes at the same time.

There are  many more reasons for the externally rotated limb/foot, for example vestibular dysfunction, cerebellar dysfunction, core dysfunction, impaired normal arm swing and the list goes on. We have talked about many of these reasons on many of our blog posts and podcasts.

Mental gymnastics when it comes to the brain are important, Keep your gait and human movement game sharp, work through scenarios in your head regularly because it is what is necessary when you are working up a client.  

Shawn and Ivo

the gait guys

Podcast 58: Brain Mapping Injuries, Muscle Activation & Sleep

The intricacies of how the brain maps a compensation pattern.

A. Link to our server:

Direct Download: 

http://traffic.libsyn.com/thegaitguys/pod_58f.mp3

Permalink: 

http://thegaitguys.libsyn.com/podcast-58-brain-mapping-injuries-muscle-activation-sleep

B. iTunes link:

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

C. Gait Guys online /download store (National Shoe Fit Certification and more !) :

http://store.payloadz.com/results/results.aspx?m=80204

D. other web based Gait Guys lectures:

www.onlinece.com   type in Dr. Waerlop or Dr. Allen,  ”Biomechanics”

_______________
Today’s Show notes:
Neuroscience pieces:
1. Gait Posture. 2013 Jul;38(3):549-51. doi: 10.1016/j.gaitpost.2013.02.008. Epub 2013 Mar 11.

Altered gait termination strategies following a concussion.

2. lack of sleep, brain damage……… honor  your recovery days and as importantly, honor the things that make you a better runner, that includes sleep !!!!!

4. New minimalist casual shoes:

Zed’s
Well, how convenient. A fantastic picture for teaching from the cover of one of our favorite magazines.
For this post, lets start with the gal on the left in the pink shirt. 1st of all, she is running in flip flops. Since these require so much long …

Well, how convenient. A fantastic picture for teaching from the cover of one of our favorite magazines.

For this post, lets start with the gal on the left in the pink shirt. 1st of all, she is running in flip flops. Since these require so much long flexor activity to keep them on, not the best footwear choice, in our opinion. Check out that exaggerated left sided arm swing. This goes to propel herself forward. Why the extra effort? Check out her right (stance phase leg). What do you see? The knee points outward while the foot is planted. We are looking at either external tibial torsion or a femoral retrotorsion. Did you pick up the compensatory head tilt to the left? The vestibular system has become involved, and the trapezius and levator scapula seem to be it’s target (thus the shoulder hike and ipsilateral rotation), as well as the ipsilateral lateral benders and rotators of the cervical spine, namely the splenius cervicis and capitis (the multifidus/rotatores are contralateral rotators).

How about the subtle pelvic shift to the right? and the mild crossover gait (note the adduction of the left knee across midline).

It would be great to see a shot of her barefoot to see what changes, as increased long flexor activity has both local (impaired ankle rocker, excessive forefoot inversion, reciprocal inhibition of the anterior compartment muscles of the lower leg) as well as long distance (namely increased flexor drive to the brainstem and cerebellum) implications. We would want to see this (as well as examine her) before making any recommendations other than LOSE THE FLIP FLOPS GIRLFRIEND.

Wow, all that and we have only scratched the surface.

We remain the geeks of gait: Ivo and Shawn

Activation, Cortical Remapping and what you are doing wrong to your people.

We are getting ready to step back into the studio to record podcast 58. We have been touching upon this topic off and on in the last 2 podcasts and we are going back in for more on pod #58 because this stuff is just too important not to beat it to a further pulp.  

The gist of this article is that cortical remapping occurs with injuries that are not 100% resolved. Lots of coaches and trainers out there are trying their hands at muscle “activation” and other new trendy tricks and they are missing the boat and making people worse if they are not doing a good sound clinical history and examination. You can activate any muscles and get what appears to be a miracle response, we can teach a 8 year old how to do activation and get a miracle response, but is it the right response or have you created a temporary compensation for your client (right before you send them into training or competition) ?  Activation is a 2 way street, there is the input into the brain and a corresponding motor output. If you are just rubbing out some muscles and get a stronger muscle test afterwards, and that is as far as your thoughts go before you turn your athlete loose, then you are a liability in the system. Are you part of the problem or part of the solution ?

Here are 2 paragraphs from this brilliant article. This is worth your time. As a client adapts to their unresolved, partially resolved (yes, even 95% is unresolved) injury(s) a secondary cascade of neurological changes ensue that often force new cortical remapping.  A remapping that is not as fundamentally safe or as sound as the pre-injury mapping yet one that is necessary for protecting further or other injuries. Yet, because it is not the original pristine pattern, it is also one that can begin undercurrents to corrupt other patterns of stability, mobility and movement in cortical and subcortical mappings. Understanding cortical excitability is important, and it can work for you and your client or against you both. It can be used for good or evil.  

If after you read these 2 paragraphs taken from the Alan Needle article in LER (link) you think you might be part of the problem or realize that you are not the magician you think you are, then good, you are on the track to self enlightenment and actually helping people.  Go read Alan’s article and breathe deep, ready to absorb and start yourself into understanding that you are really fixing the brain and not always the muscle, and that means you are gonna have to learn about the brain and how it works and more so how it can deceive you and your client and your training, treatments or therapy.

Come join us on The Gait Guys podcast 58 later this week as we delve into this topic deeper and more broadly.

Shawn and Ivo

PS: nice article Dr. Needle. Thank you !

http://lowerextremityreview.com/article/the-brain-a-new-frontier-in-ankle-instability-research

“Recently Wikstrom and Brown proposed a hypothetical cascade of events that would affect an individual’s ability to “cope” following an ankle sprain and provide a rationale for the varying contributors to instability. For an individual starting from a point of normal function, a lateral ankle sprain will trigger a consistent pattern of changes to the joint from the inflammatory process. Swelling will increase pressure on the joint’s mechanoreceptors, and pain will contribute to inhibition of the reflexes to the joint (arthrogenic inhibition). Together, this means patients will have difficulty sensing the joint and subsequently stabilizing it while excessive mechanical laxity will increase this loss of stability.19

Inflammatory changes may be similar across all patients; however, as symptoms remain and the patient adapts after his or her injury, a secondary cascade of neurological changes may occur that may include cortical remapping. In some patients, these adaptations may be beneficial and serve to protect the joint from further injury. Other patients may maladapt, as sensorimotor reorganization changes the nervous system’s perception of the joint. Variable amounts of laxity, proprioception, and cortical excitability exist throughout populations of healthy, previously injured, and functionally unstable joints. Where these populations diverge may be related to how each is scaled relative to the others. For instance, a joint with greater amounts of laxity may have higher proprioception and excitability to aid in stabilizing the joint, but following injury, these factors may become decoupled, leading to errors in movement and coordination.19”  -Alan Needle, PhD

 

More on EVA foam, impact loading behaviors, and adding shoe inserts.

A few weeks ago we wrote about some thoughts on the maximalist shoe foam trend and how it is possible that more foam could mean alterations in impact loading behaviors that could lead to problems (note we used the word could, and not will).  If there are pre-existing proprioceptive deficits in a limb these issues most likely will rise to the surface. 

The EVA foam in shoes is primarily used to absorb forces via air flow through interconnected air cells in the EVA during shoe deformation under body-weight. When the shoe has seen a finite number of compressive cycles the air cells collapse and the EVA can compact on itself leaving the shoe with an negatively impacting area of compression to fall into.  Shock absorption may be impacted and possibly lead to injury.

The Robbins study we discussed a few weeks ago (link) suggested that the reduction of impact moderating behaviour is 

Reduction of impact-moderating behavior is a response to loss of stability induced by soft-soled cushioned shoes: Humans reduce impact-moderating behavior in direct relation to increased instability.This is presumably an attempt to achieve equilibrium by obtaining a stable, rigid support base through compression of sole materials. Humans reduce impact-moderating behavior, thereby amplifying impact, when they are convinced that they are well protected by the footwear they are wearing. 

These were important points but we wanted to bring to your awareness of the component of the shoe you may have not thought of to this point, the foam foot bed that comes with the shoe, or ones you might add to the shoe  yourself post-purchase. With what we have just taught you in our last blog post and this blog post, we will let you make the connection we are suggesting you be aware of when it come to more foam, changes in foam as the shoes and inserts degrade and impaired impact loading behaviors.

There are just 3 brief study summaries here, take the time to read them and read between the lines now that we have educated you a little better in how to think about them.

Shawn and Ivo

J Appl Biomech. 2007 May;23(2):119-27.

Effects of insoles and additional shock absorption foam on the cushioning properties of sport shoes.

The purpose of this study was to investigate the effects of insoles and additional shock absorption foam on the cushioning properties of various sport shoes with an impact testing method. 

The results of this study seemed to show that the insole or additional shock absorption foam could perform its shock absorption effect well for the shoes with limited midsole cushioning. 

Further, our findings showed that insoles absorbed more, even up to 24-32% of impact energy under low impact energy. 

It seemed to indicate that insoles play a more important role in cushioning properties of sport shoes under a low impact energy condition.

_______

Biomed Mater Eng. 2006;16(5):289-99.

Role of EVA viscoelastic properties in the protective performance of a sport shoe: computational studies.

 Using lumped system and finite element models, we studied heel pad stresses and strains during heel-strike in running, considering the viscoelastic constitutive behavior of both the heel pad and EVA midsole. In particular, we simulated wear cases of the EVA, manifested in the modeling by reduced foam thickness, increased elastic stiffness, and shorter stress relaxation with respect to new shoe conditions. Simulations showed that heel pad stresses and strains were sensitive to viscous damping of the EVAWear of the EVA consistently increased heel pad stresses, and reduced EVA thickness was the most influential factor, e.g., for a 50% reduction in thickness, peak heel pad stress increased by 19%. We conclude that modeling of the heel-shoe interaction should consider the viscoelastic properties of the tissue and shoe components, and the age of the studied shoe.

________________

J Biomech. 2004 Sep;37(9):1379-86.

Heel-shoe interactions and the durability of EVA foam running-shoe midsoles.

A finite element analysis (FEA) was made of the stress distribution in the heelpad and a running shoe midsole, using heelpad properties deduced from published force-deflection data, and measured foam properties. The heelpad has a lower initial shear modulus than the foam (100 vs. 1050 kPa), but a higher bulk modulus. The heelpad is more non-linear, with a higher Ogden strain energy function exponent than the foam (30 vs. 4). Measurements of plantar pressure distribution in running shoes confirmed the FEA. The peak plantar pressure increased on average by 100% after 500 km run. Scanning electron microscopy shows that structural damage (wrinkling of faces and some holes) occurred in the foam after 750 km run. Fatigue of the foamreduces heelstrike cushioning, and is a possible cause of running injuries.

 

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Remember this kiddo?

We have been following the natural development of this little guy for some time now. For a review, please see here (1 year ago) and here (2 years ago) for our previous posts on him.

In the top 2 shots, the legs are neutral. The 3rd and 4th shots are full internal rotation of the left and right hips respectively. The last 2 shots are full external rotation of the hips.

Well, what do you think now?

We remember that this child has external tibial torsion and pes planus. As seen in the supine photo, when the knees face forward, the feet have an increased progression angle (they turn out). We are born with some degree / or little to none, tibial torsion and the in-toeing of infants is due to the angle of the talar neck (30 degrees) and femoral anteversion (the angle of the neck of the femur and the distal end is 35 degrees).  The lower limbs rotate outward at a rate of approximately 1.5 degrees per year to reach a final angle of 22 degrees….. that is of course if the normal de rotation that a child’s lower limbs go through occurs timely and completely.

He still has a pronounced valgus angle at the the knees (need a review on Q angles? click here). We remember that the Q angle is negative at birth (ie genu varum) progresses to a maximal angulation of 10-15 degrees at about 3.5 years, then settles down to 5-7 degrees by the time they have stopped growing. He is almost 4 and it ihas lessend since the last check to 15 degrees.

His internal rotation of the hips should be about 40 degrees, which it appears to be. External rotation should match; his is a little more limited than internal rotation, L > R. Remember that the femoral neck angle will be reducing at the rate of about 1.5 degrees per year from 35 degrees to about 12 in the adult (ie, they are becoming less anteverted).

At the same time, the tibia is externally rotating (normal tibial version) from 0 to about 22 degrees. He has fairly normal external tibial version on the right and still has some persistent internal tibial version on the left. Picture the hips rotating in and the lower leg rotating out. In this little fellow, his tibia is outpacing the hips. Nothing to worry about, but we do need to keep and eye on it.

What do we tell his folks?

  • He is developing normally and has improved significantly since his original presentation to the office
  • Having the child walk barefoot has been a good thing and has provided some intrinsic strength to the feet
  • He needs to continue to walk barefoot and when not, wear shoes with little torsional rigidity, to encourage additional intrinsic strength to the feet
  • He should limit “W” sitting, as this will tend to increase the genu valgus present
  • We gave him 1 leg balancing “games” and encouraged agility activities, like balance beam, hopping, skipping and jumping on each leg individually

We are the Gait Guys, promoting gait and foot literacy, each and every post.

Podcast 57: The Brain, Ankle Instability, Heel Striking

A. Link to our server:

Direct Download: 

http://traffic.libsyn.com/thegaitguys/pod_5777final.mp3

Permalink: 

http://thegaitguys.libsyn.com/podcast-57-the-brain-ankle-instability-heel-striking

B. iTunes link:

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

C. Gait Guys online /download store (National Shoe Fit Certification and more !) :

http://store.payloadz.com/results/results.aspx?m=80204

D. other web based Gait Guys lectures:

www.onlinece.com   type in Dr. Waerlop or Dr. Allen,  ”Biomechanics”

________________________________________

* Today’s show notes:

Neuroscience

Focus on BDNF: Brain Derived Neurotrophic Factor and Gait

http://www.ncbi.nlm.nih.gov/pubmed/10868966

Diabetes. 2000 Mar;49(3):436-44.
Brain-derived neurotrophic factor regulates glucose metabolism by modulating energy balance in diabetic mice.

http://ep.physoc.org/content/94/12/1153.full

Experimental Physiology –
Hot Topic Review
Role of exercise-induced brain-derived neurotrophic factor production in the regulation of energy homeostasis in mammals

The Brain: A new frontier in ankle instability Research
http://lowerextremityreview.com/article/the-brain-a-new-frontier-in-ankle-instability-research

Young Girls and Future injury risk.
http://lowerextremityreview.com/news/in-the-moment-sports-medicine/neuromuscular-training-in-young-girls-boosts-skills-may-reduce-future-risks

PRP review:
http://lowerextremityreview.com/news/in-the-moment-sports-medicine/platelet-rich-progress-data-support-prp-use-for-heel-pain

case: gait guys,

so i got orthotics which hurt like crazy (only on my bad foot). these were not the answer for me. i have an appointment with a hip specialist to see if my  … .
phil

DISCLAIMER

elliptical questions: 
Tried searching your blog but did not find anything on ellipticals.

What correct position is needed to use the machine?
I assume one that would take you out of the anterior pelvic tilt?
By doing this, would that enable  … . 
Q  :)

Alternative office furniture to avoid sitting at a desk all day
http://www.latimes.com/health/la-he-healthy-workplace-desks-20140222,0,5603953.story

Heel Landing Beats Midfoot In Half-Marathon Study
http://www.runnersworld.com/running-tips/heel-landing-beats-midfoot-in-half-marathon-study
More shoe foam may mean more problems.
Last night we had a great online teleseminar (www.onlinece.com).  The talk was minimialism.  Here was 2 of our take home points:
More foam in the shoe is not always good. 
“Shoes with cushioning fail to a…

More shoe foam may mean more problems.

Last night we had a great online teleseminar (www.onlinece.com). The talk was minimialism. Here was 2 of our take home points:

More foam in the shoe is not always good.

“Shoes with cushioning fail to absorb impact when humans run and jump, and amplify force under certain conditions, because soft materials used as interfaces between the foot and support surface elicit a predictable reduction in impact-moderating behavior. ” -Robbins

Basically barefoot feet, and even shoes with thinner foam/soled shoes, tend to judge impact more precisely because there is less foam to dampen proprioceptive input. The more foam you stack under the foot, the more material that must be deformed before a sufficiently rigid surface can be detected by the foot. Think of this, what do we do in rehab ? We stand people on stacked foam to give them an unstable surface (if they have championed balance challenges on a stable surface first, this is an important first step). When the foot cannot find a firm platform it searches for stability and drowns in the instability. This can be what more foam under the foot provides, inability to reference stable ground surface can negatively impact proprioceptive joint and tissue receptors.

2. Impact loading behaviors.

if we know the surface (the shoe or the actual surface/ground) is unstable, we will modify the pending impact loading behavior. In other words, you will jump differently onto a frozen puddle than you would dry ground. Studies have shown that the more foam a shoe has (ie. the more the potential instability from the example above) the greater the reduction of impact moderating behavior.

Humans reduce impact-moderating behavior in direct relation to increased instability.- Robbins

hope to see you in the next online teleseminar in 4 weeks !

shawn and ivo

reference:

BioMechanics April 1998

Materials: Do soft soles improve running shoes?
Most athletic shoes advertise injury protection through “cushioning,” but real world studies have not shown impact moderation.
By Steven Robbins, MD, Edward Waked, PhD, and Gad Saad, PhD

Tomorrow we lecture on Minimalistic Footwear and its impact on runners on onlinece.com and chirocredit.com. Join Us. Biomechaics 318; 8PM Eastern, 7 Central, 6 Mountain, 5 Pacific.
All the cool people will be there and if you attend, you will know w…

Tomorrow we lecture on Minimalistic Footwear and its impact on runners on onlinece.com and chirocredit.com. Join Us. Biomechaics 318; 8PM Eastern, 7 Central, 6 Mountain, 5 Pacific.

All the cool people will be there and if you attend, you will know why barefoot is not the same as minimal

Yep, you read it here. Exercise good: Sugar…Not so good for your brain
“Thus, BDNF appears to be released from the human brain, and the cerebral output of BDNF is negatively regulated by high plasma glucose levels, but not by high levels of i…

Yep, you read it here. Exercise good: Sugar…Not so good for your brain

“Thus, BDNF appears to be released from the human brain, and the cerebral output of BDNF is negatively regulated by high plasma glucose levels, but not by high levels of insulin”

Let us boil it down to two simple equations for you:

Exercise = More BDNF

Sugar (Glucose) = Less BDNF

So what is BDNF? It stands for “Brain Derived Neurotrophic Factor”. It’s the stuff that makes our brain grow.

Neurotrophins are a family of structurally related growth factors, including brain-derived neurotrophic factor (BDNF), which exert many of their effects on neurons in the brain, but also many other metabolic processes in the body.

Brain-derived neurotrophic factor has been shown to regulate neuronal
development and to modulate synaptic plasticity (ie it is a mind expanding compound; literally). Recent studies show that BDNF is also expressed in non-neurogenic tissues, including skeletal muscle. BDNF has also been identified as a key component of the hypothalamic pathway that controls body weight and energy homeostasis and it appears to
be a major player not only in central metabolic pathways,but also as a regulator of metabolism in skeletal muscle.

So, before you replenish those glycogen stores with some simple sugars post run or workout; remember that it may be at the expense of your brain function. Are we saying not to replenish? No, we are saying stick to lower glycemic choices, which yes, will fill the glycogen stores slower, but can help preserve your noggin. Glucose IS the preferred fuel of the brain, but it can make it from fats and proteins as well; remember something called gluconeogenesis from physiology class? Some of the latest studies show that ketosis isn’t as bad as we previously thought, but that is the subject of another post…

We are The Gait Guys and we are all things gait; even those that are peripherally related.



Krabbe KS, Nielsen AR, Krogh-Madsen R, Plomgaard P, Rasmussen P, Erikstrup C, Fischer CP, Lindegaard B, Petersen AM, Taudorf S, Secher NH, Pilegaard H, Bruunsgaard H & Pedersen BK (2007). Brain-derived neurotrophic factor (BDNF) and type 2 diabetes. Diabetologia 50, 431–438.

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Vintage Nike Niobe

I best recall being told that this shoe was worn three times, the third run was a marathon, and as you can see that was its last day on the road.

This is what happens when someone who should not be in a curve lasted shoe, chooses to run in one. The Nike Niobe was a curve lasted simple shoe. It was very light weight, small stack height and narrow ramp from heel to forefoot. This was likely a fast shoe for someone, for the right foot type. 

This person was obviously having some distal toe pain, so they pre-shredded the tip of the shoe to offer some “space”. Perhaps they were sized wrong, perhaps this person had a tender 2nd toe/nail.  But this is not the purpose of today’s blog post.

Today we wanted to bring up shoe LASTS again.

The Last (the part between the midsole and insole)

Strictly speaking, a last is the mold or template for creating the shoe. It defines theshape of a shoe. Remember that men’s and women’s feet are shaped differently. Men (usually) have rectangular feet (the forefoot and heels are wider, or have less difference in width); Ladies (usually) have triangular feet (the forefoot is much wider than the heel). This is why it is important to know if the shoes you are fitting are a men’s or women’s specific last. Many times, the shoes come off the production line and the boy shoes are blue and the girls pink: both made from the same last.

The last determines whether a shoe is  a high, medium or low volume shoe… Pretty important, if they have a high instep or flat foot. Companies like Altra have as many as 6 different, sex specific lasts. This results in a wide range of fit (and thus a bigger market share).

Take off your clients shoes and look at their feet. Note their shape and curve. Lasts need to match that “curve” so they can be relatively straight or curved (this refers to the shape of the “sole” of the shoe: see above). Turn a shoe over and look at the sole. Mentally bisect the heel with a line going to the front of the shoe. If the line bisects the front of the shoe, it is a straight lasted shoe (this corresponds to the axis of the 2nd metatarsal, or slightly lateral to it). If more of the shoe falls medial to this (more of the sole on the big toe side) it has a curved last.

Curved last shoes can vary in the degree of curvature. Curved last shoes are designed to help control pronation, as they provide medial support and slow its rate by causing a relative supination of the foot after heel strike (it weights the lateral border of the shoe for a longer period of time, theoretically allowing less pronation). Curved last shoes can put more motion into a foot, especially one with limited rearfoot motion (it still must pronate, but due to the lack of rearfoot motion, the forefoot must compensate and now must do so in a shorter period of time).The last is the surface that the insole of the shoe lays on, where the sole and upper are attached.    Shoes are board lasted, slip lasted or combination lasted. A board lasted shoe is very stiff and has a piece of cardboard or fiber overlying the shank and sole (sometimes the shank is incorporated into the midsole or last) .  It is very effective for motion control (pronation) but can be uncomfortable for somebody who does not have this problem.  A slip lasted shoe is made like a slipper and is sewn up the middle.  It allows great amounts of flexibility, which is better for people with more rigid feet.  A combination lasted shoe has a board lasted heel and slip lasted front portion, giving you the best of both worlds. 

When evaluating a shoe, you want to look at the shape of the last (or sole).   Bisecting the heel and drawing an imaginary line along the sole of the shoe determines the last shape.  This line should pass between the second and third metatarsal.  If you do this to the Nike Niobe shoe you will see a nice gentle curved line, it is not as much as one would think because the severity of the carved away instep/arch gives it the appearance of a more curved last than it truly is.  Drawing this imaginary line, you are looking for equal amounts of shoe to be on either side of this line. Shoes have either a straight or curved last.  The original idea of a curved last (banana shaped shoe) was to help with pronation.  A curved last puts more motion into the foot and may force the foot through mechanics that is not accustomed to. Most people should have a straight last shoe. Folks who have pronation challenges will do better with a semi-curved to straight lasted shoe.  Few people need a truly curve lasted shoe. A general rule of thumb is: You really can’t go wrong with a straight last. It will work for all feet, especially if you are using an orthotic. This is especially important with people with forefoot abductus, moderate to severe pronators and rigid feet (rear or forefoot). A forefoot abductus and severe pronator’s feet will move laterally in the shoe, often causing crushing, rubbing, cramping and blistering of the little toe against the side of the shoe. A rigid foot, because the foot needs to be able to pronate at the mid and forefoot, will have a similar problem. You can use a curved last with people with mobile or hypermobile feet, provided their pronation is not too severe (clinical judgment, trial and error).

You won’t see any Nike Niobe’s anymore, they are even mere ghost stories even on the internet.  It is cool to see where shoe fabrication logic was long ago, and to see how far it has come. RIP Niobe.  

This was clearly an example of a heavy pronator (note the medial heel blow out) starting at the rearfoot heel contact. They were also likely a heel striker, but that was “the thing” back then.  The gentle curve in this shoe’s last did not do this person any favors, heck this runner was likely crippled for a week with arch pain, tibialis posterior pain and medial knee pain.  A shoe can really tell a story !

Want to learn more about shoe anatomy and how to pair shoes to certain foot types ?  Do you find yourself wanting to know more about a forefoot varus, forefoot valgus, compensated and uncompensated variants of these or rearfoot variances ? Here is where you should start:

Gait Guys online /download store (National Shoe Fit Certification and more) :

http://store.payloadz.com/results/results.aspx?m=80204

Or, other web based Gait Guys lectures: www.onlinece.com   type in Dr. Waerlop or Dr. Allen,  ”Biomechanics”

Thanks to Wayne  over at Dick Pond Shoes for this little gift 10 years ago. We came across it doing some thinning out of “the herd” of great shoe pathology samples we like to keep.

Shawn and Ivo, The Gait Guys

Today’s Rewind includes an older “Gait Guys at the Movies” clip of Carey Grant! Sit back and enjoy!

Run, Carey, Run?

Lets look at this Hitchcock classic “North by Northwest” and check out Cary’s form.

1st of all, what an arm swing! Think of all that energy it is sapping from the rest of his muscular system. He must be hiding something, but what? We can only see him from the waist up, so we may never actually know. Did you notice how he initially only turns to the right? Did you pick up on the flexion at the waist? How about that torso bob from side to side? Not much to his hip abductors now are there?

The only thing he has going for him is he is wearing leather soled shoes, which have been shown to have one of the lowest impact loading on the body (yes, you read that right; increased cushioning INCREASES impact forces, but that’s not what we are here to talk about). Oh yea, he actually impacts the ground at the end of the sequence. I guess if his technique was better, he would have hit even HARDER.

Next sequence, we are off to a good start, look at that forward lean to start! This is essential to good technique. He loses that form pretty quickly; we can still see that forward flexion at the waist; certainly costing him energy by not using his core.

Finally, we get a posterior view at the end, but the uneven surface makes it difficult to make an analysis.

We think Cary would certainly give Lola a run for her money. Cary, next time, engage your core and watch your step…

We Remain….The Gait Guys

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Holy Hand Grenades! What kind of shoe do I put these feet in?

Take a look at these feet. (* click on each of the photos to see the full photo, they get cropped in the viewer) Pretty bad, eh? How about a motion control shoe to help things along? NOT! OK. but WHY NOT? Let’s take a look and talk about it.

To orient you:

  • top photo: full internal rotation of the Left leg
  • 2nd photo: full internal rotation of the Right leg
  • 3rd photo: full external rotation of the Left leg
  • last photo: full external rotation of the Right leg

Yes, this gal has internal tibial torsion (yikes! what’s that? click here for a review).

Yes, it is worse on the Left side

Yes, she has a moderate genu valgus, bilaterally.

If someone has internal tibial torsion, the foot points inward when the knee is in the saggital plane (it is like a hinge). The brain will not allow us to walk this way, as we would trip, so we rotate the feet out. This moves the knee out of the saggital plane (ie. now it points outward).

What happens when we place a motion control shoe (with a generous arch and midfoot and rearfoot control) under the foot? It lifts the arch (ie it creates supination and it PREVENTS pronation). This creates EXTERNAL rotation of the leg and thigh, moving the knee EVEN FURTHER outside the saggital plane. No bueno for walking forward and bad news for the menisci.

Another point worth mentioning is the genu valgus. What happens when you pick up the arch? It forces the knee laterally, correct? It does this by externally rotating the leg. This places more pressure/compression on the medial aspect of the knee joint (particularly the medial condyle of the femur). Not a good idea if there is any degeneration present, as it will increase pain. And this is no way to let younger clients start out their life either.

So, what type of shoe would be best?

  • a shoe with little to no torsional rigidity (the shoe needs to have some “give”)
  • a shoe with no motion control features
  • a shoe with less of a ramp delta (ie; less drop, because more drop = more supination of the foot (supination is plantarflexion, inversion and adduction)
  • a shoe that matches her sox, so as not to interfere with the harmonic radiation of the colors (OK, maybe not so much…)

Sometimes giving the foot what it appears to need can wreak  havoc elsewhere. One needs to understand the whole system and understand what interventions will do to each part. Sometimes one has to compromise to a partial remedy in one area so as not to create a problem elsewhere. (Kind of like your eye-glass doctor. Rarely do they give you the full prescription you need, because the full prescription might be too much for the brain all at once.  Better to see decent and not fall over, than to see perfectly while face down in the dirt.) 

Want to know more? Consider taking the National Shoe Fit Certification Program. Email us for details: thegaitguys@gmail.com.

We are the Gait Guys, and yes, we like her sox : )