Factors that adversely effect the natural history of the pronated foot.→

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“Risk Factors that may adversely modify the natural history of the pediatric pronated foot."  Clin Podiatr Med Surg. 2000 Jul;17(3):397-417. Napolitano C, Walsh S, Mahoney L, McCrea J.Department of Orthopaedic Surgery, Loyola University Medical Center, Maywood, Illinois, USA.

This article is a nice follow up to the video post from yesterday. The article talks about the flexible and rigid flat foot.  In yesterday’s video example we are dealing with a flexible flat foot deformity.  When he was non-weightbearing (which wasn’t seen in the video) he formed an arch.  As you can see in the video upon weightbearing the arch disappears but you can see that with the correct patterning employed, he can find an arch.  This is what we term a flexible flat foot deformity.  These types of feet have potential if there is sufficient muscular ability and if hyperlaxity in the ligamentous system can be overcome by neuromuscular support. If not, an orthotic may need to be utilized and be assistive.  The rigid flat foot, is one that does not form a competent arch, ever.  These feet are what they are, flat.  But, keep in mind…… some genetics do render a competent flatter foot.  Some of the strongest feet we have seen are on very low arched people / runners.  So, flatter does not always mean weak, be careful.  What you see is not necessarily what you get, even a rusted out Ford Pinto might have a Ferrari engine in it……. you just don’t know by looking, you have to test the competency of the foot (another example, look at Arnold Palmer’s golf swing, it isn’t the prettiest swing by any means…… but you probably wouldn’t bet a penny against him even these days, if you get our drift.)

As the abstract says. "Normally developing infants have a flexible flatfoot and gradually develop a normal arch during the first decade of life."  The key word is NORMALLY.   You must consider risk factors that may affect the foot in its overall development.  The risk factors include ligamentous laxity, obesity, rotational deformities, tibial influence, pathological tibia varum, equinus, presence of an os tibiale externum, and tarsal coalitions.

Again, this is a nice follow up to our video from yesterday and brings home some additional good points to cogitate over. We knew we had a flexible flat foot with potential.  Knowing what you are starting with it vital for your success in treating the problem, and vital in determining long term success. 

We are, The Gait Guys ………. and even a bit geeky in neurodevelopmental physiology. (Yes, we have no life.) 

Shawn and Ivo

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Abstract of the Journal Article……. the link to the article is at the top of the blog post if you wish to obtain the article for further study.

Here is their abstract:

"Flatfoot is one of the most common conditions seen in pediatric podiatry practice. There is no universally accepted definition for flatfoot. Flatfoot is a term used to describe a recognizable clinical deformity created by malalignment at several adjacent joints. Clinically, a flatfoot is one that has a low or absent longitudinal arch. Determining flexibility (physiologic) or rigidity (pathologic) is the first step in management. A flexible flat foot will have an arch that is present in open kinetic chain (off weight-bearing) and lost in closed kinetic chain (weight-bearing). A rigid flatfoot has loss of the longitudinal arch height in open and closed kinetic chain. According to Mosca, "The anatomic characteristics of a flatfoot are excessive eversion of the subtalar complex during weight-bearing with plantarflexion of the talus, plantarflexion of the calcaneus in relation to the tibia, a dorsiflexed and abducted navicular and a supinated forefoot.” Normally developing infants have a flexible flatfoot and gradually develop a normal arch during the first decade of life. When evaluating an infant for a pronated condition, the examiner must also consider other risk factors that may affect the foot in its overall development. These contributing factors will play a role in the development of a treatment plan. The risk factors include ligamentous laxity, obesity, rotational deformities, tibial influence, pathological tibia varum, equinus, presence of an os tibiale externum, and tarsal coalitions. The authors realize other less significant factors exist but are not as detrimental to the foot as the primary ones discussed in depth. The primary risk factors that affect the pronated foot have been outlined. The clinician should always examine for these conditions when presented with a child exhibiting pronatory changes. A thorough explanation to the parents as to the consequential effects of these risk factors and their effects on the pediatric pronated foot is paramount to providing an acceptable comprehensive treatment program. Children often are noncompliant with such treatments as stretching and orthotic maintenance. The support of the parents is crucial to maintaining an effective treatment program continued at home.“

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Stage 1 of Correcting a flat foot, video demonstration.

Here is a case of a young man that was brought into us by his parents. Their concern was that their son was displaying what they thought was foot weakness. 

At the beginning of the video you can see that his foot progression angle is significant.  Certainly greater than the 10-15 degree “so called” normal range.  His arches are also somewhat collapsed. His knees were also displaying some hyperextension which is quite common with flat foot posturing.

This was his third visit into our office. He was given the corrective neuromuscular strategy that you see here and some specific exercises to help him get to this stage of correction.  The first stage of any correction is developing the awareness of what you are doing wrong (ie. become consciously aware of your incompetence). That was session one.  Session two focused on developing this corrective pattern, helping him find the skills to develop some conscious competence with a more normal foot stability skill pattern (endurance and strength still need to be added). 

Here you will see that, when queued, he immediately moves into a narrower base of stance (this will always happen when they can form a competent foot tripod, as you can see here).  In other words, the worse the foot collapse, the wider the feet will be positioned.  In his case, he now positions his feet under his hips and knees. 

You will also see the early success (after just 2 visits !) of a critical neuromuscular pattern.  He is showing some competence in holding the arch up and letting the toes move into flexion onto the ground.  Most flat footed children cannot separate “maintaining arch up, and moving into toes down”, rather they are into the pattern of “when the toes drop to the floor, the arch drops as well”.  This is a critical pattern (ability to hold arch up) to recognize and develop.  The child must develop the ability to independently flex and extend the toes on a static arch, while holding tripod,  before gait retraining can ensue.  This is mainly because the speed of gait and difficulty of single leg stance while displaying the correct pattern is just too much of a skill mastery issue. Often these pupils do not have enough hip frontal plane stability nor pelvic stability as well.

Also, note that he uses the skill of toe extension to help with arch height determination.  This goes right back to our blog posts last week on the Windlass Mechanism.  He is using the power of the windlass effect (toe extension) to take up the slack in the plantar fascial around the great toe metatarsal joint and thus pull the rear foot towards the forefoot (ie. raising the arch via this mechanism ! ).  Without a competent windlass a competent arch cannot be obtained (thus the ridiculousness of plantar fascial release surgery !).  Additionally, understanding the windlass and the effects of this simple video should give you insight into our success in quickly treating plantar fascitis. 

(addendum: also note at the end of the video that i ask him to collapse into his old pattern, this was after 30 minutes of corrective motor pattern exercises.  I laugh because in a solid posture that he shows at the end of the video, plus 30 minutes of new patterning, he found it difficult to find his old collapsed pattern.  This is a frequent occurance ! It gives you and the patient confidence that headway is being made.)

You must develop isometric, eccentric and concentric strength of the plantar intrinsic muscles that stabilize, raise, and control the lowering of the arch (as well as the arch controlling extrinsic muscles such as tibialis anterior and posterior among others) if you are going to make a difference in someones foot mechanics.  Just putting someone into a pair of ANY minimalist shoe (let alone barefoot) doesn’t guarantee strengthening of the foot or a remedy for a pair of feet like in this video. The process is a little more complicated than slipping on a pair of low ramp angle “shoes” and wearing them all day long…….in these types of cases all it does is raise their risk of injury or further foot incompetence down the road. 

For our fellow clinicians out there who are following us and trying to learn more about this kind of stuff……. wouldn’t your clinical world be nice if just prescribing a minimalist shoe would strengthen the foot in the correct pattern !?  We argue that, as in this kids foot, they would strengthen his foot in his poor postured patterns. So, we guess these companies are not lying when they say their shoes “strengthen” your feet, they just leave out the word “correctly”.

So, we do not argue with the point that going minimalist will strengthen your foot…… the question is “do you want to strengthen the correct pattern or a compensated one?”. 

here at The Gait Guys…….we know which pattern we want to strengthen.

We remain strong advocates that not all feet belong in minimalist shoes…… at least not initially, and some, never.  It would be nice if just slipping on a shoe could fix all of your foot problems, but it just isn’t that easy.  This is the topic no one is talking about, except The Gait Guys ……… because it doesn’t sell shoes.

There is much more to it than this video shows……. but we have to start somewhere.  Educating you with the issues we feel passionate about is the first step sometimes.

We remain…….obviously passionate………..

Shawn and Ivo….. The Gait Guys

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The London Looter’s Getaway Stride: Gait analysis by The Gait Guys We did this one yesterday in collaboration with our good friends at Zero-drop.com on their awesome blog.  Check out their stuff. The images coming out of England of young hoodi…

The London Looter’s Getaway Stride: Gait analysis by The Gait Guys

We did this one yesterday in collaboration with our good friends at Zero-drop.com on their awesome blog.  Check out their stuff.

The images coming out of England of young hoodie-wearing hoodlums rioting, stealing, smashing store windows, torching cars, and causing all-out mayhem in London and elsewhere is unsettling for several reasons. What exactly are these lawless yobs protesting? Are these race-induced riots? Public outcry over political and social injustice? Or are these roaming gangs of hooligans more interested in something else–like getting their hands on free stuff such as 46-inch flat-screen high-definition televisions and Nike sneakers.

In the photo here, it appears as though a young lad has just swiped a bottle of something lip smacking  from a Manchester food store. It seems that he dressed for the occasion –Adidas track suit and running shoes–  to facilitate a quick, speed getaway. He’s much too young to be hitting the bottle. Plus, one can easily assume that he didn’t expect to make the front page of the U.K. Daily Mail where this photo first appeared. (He’s probably sitting right now in juvie detention.) In any case, Zero Drop asked the Gait Guys to look at his running stride. Here’s their expert analysis:

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This chap looks a bit young to be drinking, and we doubt he is a courier. Let’s see if he will make a clean getaway, shall we?

Beginning from the bottom, we see his left foot is turned in and his knee appears straight, He does appear to be banking a left turn, but we would expect him to probably have his toe out a bit for stability since he is really banking heavily into the frontal plane (he must have a great right gluteus medius because he is holding a fairly decent pelvic line into the bank), so our guess is he has a bit of internal tibial torsion (i.e., his foot points in when his knee is straight ahead. This is usually a condition from birth). Folks with internal tibial torsion tend to have their feet in supination more, so they are excellent levers, but it usually means they lack some shock absorption (so maybe we find a forefoot valgus in that shoe, who knows). Because his knee is not in line with his line of forward progression, there will be a conflict there, which could potentially hurt his knee, besides cutting down on his mechanical efficiency (the knee is like a door hinge, and works best when moving in one direction).

His lean to the left nicely complements his probable forefoot varus (or inversion of the forefoot), so at least he has that working for him. There is a little hip sag on the left, indicating a weak gluteus medius on the right; which further cuts down his mechanical efficiency; it is moving to the right as he is cutting to the left. Holding that bottle sure cuts down on his arm swing, and he looks a bit tense, as his left shoulder is higher than the right. Like he is trying to hide something. Finally, his head posture looks forward. This facilitates his flexors and inhibits his extensors, taking away from power to drive him forward. We could go on and on, and we have. Guess we told you how to build a clock and you only wanted to know what time it is. In short, whether he gets caught depends on the biomechanics of his pursuer.

We hope he doesn’t have internet access to our blog, we would hate for him to recognize his problems and improve upon them.  We would be contributing to improved “get-aways” in the future.  That wouldn’t be good, unless someone was chasing him with a .22 , then we might feel ok with it.

Hooch for the youngers, it’s not just for the back alley’s anymore !

- the gait guys

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A different kind of Marathon: So you think you are tough ? This guy was tough. A marathon a day for over 120 days…..on one leg, with cancer. Today, a Tribute to Terry Fox.

Half of The Gait Guys grew up in Canada. We were barely a teenager when Terry began his plight.  His mission, 26 miles a day, every day, until he had crossed the expanse of Canada. He made it an amazing 120+ days in a row, 3339 miles, before his cancer returned. The whole country stood cheering watching him do something no mortal man would attempt, let along with one leg, and cancer.  Today we pay a tribute to this rockstar……. his candle went out long before it should have.  So, still think you are a tough runner ? This kind of stuff amazes us. RIP Terry.  You did more in 22 years of life than most of us will do in a lifetime.  We have neither not forgotten you nor what you stood for, and we never will.   Shawn & Ivo

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A brief gait analysis of a pretty famous barefooter from a pretty famous study…

OK so we know this rather famous person is on a treadmill, so yes, there is a component of preload to the hip extensors, as well as an increased deceleration component (but those are topics for another post!), but there is some great stuff to look at here.

1st off, note the great technique: mid to forefoot strike, good toe dorsiflexion (although it could stand to be a bit increased to help prepare for even better tripod contact), and good ankle rocker. You can see his excellent shock absorption, through midfoot pronation, ankle dorsiflexion, knee flexion and hip flexion. Also check out the awesome action of his peroneals on his L leg, driving that 1st ray down to the ground for a great foot tripod and prelude to supinaion

But did you notice something else? How about the lack of hip extension? He barely gets past zero. How about the flexion at the waist? We bet his hip flexors are tight! Is some of this caused by the treadmill? Probably, but we would need to see some non-treadmill footage to be sure.

The Gait Guys….No gait is safe from us

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Yesterday’s Video Case: The Gaits of Hell

We have received many emails on this case already. Overwhelmingly people are saying……. “Hey, this isn’t easy….. It’s easy when you guys tell us right away because we can see it."  
Yes, when we are all alone to solve these gait problems our heads can start to swim with all the variables. Gait analysis is not easy.  Even the video assessment computer programs do not give you the answers and diagnosis, they just give you variables and data.  The thinking still has to be  done at the end of the day.


I remember how much I struggled with this case back during my orthopedics residency. I remember even pulling out my undergrad notes from Univ. of Waterloo as a student of the famous Dr Stewart McGill and mapping out FBD’s (Force-Body Diagrams) on this case. Oh, the horror !!!  I still have occasional FBD nightmares, being asked to solve an equation in front of the whole class. Pure anxiety ! Holy night terrors ! But, it is amazing what a few decades of study will do for you, we can now look at this case and see things for what they are, see them quickly and know what is going on almost immediately.  It takes some time, so if you are new to this stuff, be patient…… it will come.

CASE REVIEW:

in this video we see the following:

  1. large step length off of the left foot abruptly onto the right, this step is sudden and he crashes down on to the right foot sooner than he normally would to catch his forward moving body mass. ( this will make more sense after reading #5).
  2. there is a delayed left heel rise and delayed left calf recruitment , actually, it’s not delayed, it’s absent. )
  3. the left foot remains supinated through the entire gait cycle. 
  4. the left foot shows extraordinary long toe flexor recruitment (seen on the end of the video during the foot close up)…….this point is important
  5. pelvic unleveling is apparent but a mirage for the most part. We really do not see a true Trendelenberg style gait (although it sort of looks like the left hip drops) rather, what you see is the result of the manufactured delayed left limb departure and subsequent impact at right limb load … but this is not a Trendelenberg gait, he had no Gluteus medius weakness.  Explained another way, he is having troubles departing off of the left foot (this diagnosis is the reason, he has compensated from a neurologic lesion affecting the strength of the calf) and so he extends ( behind him) the left leg longer and further than normal because he cannot push off, plus he hyperextends the left knee because of these factors. Normally, the calf fires after passive heel lift occurs. But with a lesion affecting the calf it has arrested the push off. So, in his case, the heel stays on the ground until it is dragged off from enough  forward body carriage. So, when you see this from a sagittal view the left hip will look like it is dipping as it does here, but it is not truly, he is just taking a long lurching step off of the left and onto the right, the longer left hip extension behind him sets up the illusion of a left hip drop.  Try this at home to feel this gait, walk down your hallway and try to delay the left heel rise for as long as you can.  You will find that you get into your left gluteals more, take a longer step on the left, and take a sudden lurching load onto the right limb to catch your forward progressing body mass. This is exactly what this chap is doing.  But why ? The left calf lesion. 
  6. continuing on #5, there is abrupt right frontal plane loading (because of the sudden transition from left foot to right the frontal plane is engaged longer than normal) and thus the pelvis is carried further to the right in the frontal plane.  He makes a  noble attempt to protect this range by turning out the right foot into the frontal plane (aka. increased right foot progression angle) to allow the quadricep muscles to assist the gluteus medius, abdominal obliques and lateral limb stabiliers in decelerating this frontal plane challenge.

Diagnosis:This doctor came to see me while I was completing my orthopedics residency and mid way through my course work in the neurology post doctoral program. He had been treated for mechanical low back pain with failed results ( well, to be accurate. his low back pain had resolved but pain had peripheralized into the left leg. To review, peripheralizing pain is rarely a good neurologic sign.)  After an examination showing an absent left S1 Achilles reflex it was highly suspicious we were dealing with a radiculopathy. An MRI confirmed a substantial left foraminal disc herniation obliterating the left S1 nerve root foraminally. The S1 nerve root expands into branches feeding input into the lower limb muscles.  In this case, the unfortunate group affected was the gastrocnemius almost exclusively. So in this case this makes sense to what is presented clinically and on gait evaluation. He is overutilizing his long toe flexors (fortunately untouched) as seen in the video because they are basically all that is available to him to plantarflex the foot ( create heel rise and push off).  They are certainly not well suited for this task but subconsciously the brain will use what is available to it, worthy or not. In this case they are a feeble attempt at best. There is no way the long toe flexors can lift his body mass into heel rise and propulse it forward, they are synergists of this task and not agonists / prime movers.
Sequencing Summary:So, this is a case of an aberrant or pathological gait pattern that will be permanent because the nerve damage was fixed by the time i had seen him.  Muscular wasting of the gastroc complex had already occurred.  The culprit was the space occupying lesion (disc in this case) in the left spinal vertebral foramina effacing and deforming the nerve root sufficient enough to create dennervation.  A surgical consult and EMG/NCV (as best as i can recall) confirmed this case was non-surgical at that time (no one wanted to touch the case).  The nerve damage disabled the calf so that push off was impaired.  He thus delays his ability to create adequate heel rise and propulsion so the long toe flexors are called to attempt the feat.  The foot supinates to maintain its rigidity ( it is also hard to pronate through the foot when the toe flexors are in an all out contraction). And because the heel does not rise on its own from muscular strategies, the foot waits to be lifted off of the ground by simple forward progression of the body.  This creates an increased left hip extension range and gives the appearance of a left hip drop which is a false appearance pseudo-Trendelenberg sign.  Due to the fact that he is on the left limb longer, he will be on the right limb for a shorter period.  This right stance phase is initiated abruptly as he falls from the delayed left stance phase. The abruptness of the load on the right challenges the right frontal plane as evidenced by the right foot turn out and right pelvis sway (subtle).  He then departs off the right to  begin the cycle once again.
PS: It is coming a little late, but thank you Dr McGill. Your teachings to a young undergrad set my biomechanical thinking on the right path very early in my studies of human kinetics. Thank you, Sincerely. 
Dr Shawn Allen…… The other half of The Gait Guys

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New feature: “The Gaits of Hell - Heaven’s Gaits”.

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Something new here on The Gait Guys blog…….we are introducing our case of the month in the new feature for The Gait Guys………the feature is called “The Gaits of Hell - Heaven’s Gaits”.  A bit of a play on words, but the goal of the monthly or bimonthly feature will be to put up either a disasterous gait (such as this one) or a gorgeous gait.  We will provide detailed commentary on the cases, to let you inside our heads. 

Have a look at the video today……study it.  Dissect it.  Replay it over and over until you have it figured out. In some respects, you should have a list of lets say……. 3 diagnostic differentials on your list of possibilities.  If after several viewings you cannot figure out the limp, put it aside……..and do what we do……. mimic the gait pattern and figure out what they are doing by what you are feeling.  We just gave away one of our biggest secrets with this little tidbit.  Give it a try.  We will have the answers Tuesday. 

We were going to give the summary here today…….but then we figured you might not struggle with it enough to learn what you need to from this case.  The learning principles here are huge……. so spend some time with it……get out a piece of paper and a pencil and put it all down…….. ie. which side is the limp on, which planes of motion are being violated, what are the compensations.

We actually know the precise diagnosis in this mid 20 year old doctor, he was a patient of Dr. Allen’s back in his residency days almost 16 years ago.  Yes, if you look closely that young lad with the tie and all the hair is actually me…… man what i would do for a head of hair like that once again ! 

Enjoy, …… struggle with this one……it is a good one. 

(film quality, sorry kids….. this was on VHS to start with ! Then it was converted to AVI…..and then to quicktime.  So, yes……. its a bit grainy and not HiDef……. but this case is worth every second of its painful low quality !)

Dr. Allen

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The Windlass Mechanism of the Plantar fascia. What is a Windlass anyway? After yesterdays post, we thought we might provide more insight to the Windlass mechanism and low and behold; we found AN ENTIRE PAPER on it! Wow, were we thrilled since there …

The Windlass Mechanism of the Plantar fascia. What is a Windlass anyway?

After yesterdays post, we thought we might provide more insight to the Windlass mechanism and low and behold; we found AN ENTIRE PAPER on it! Wow, were we thrilled since there is not a ton of decent stuff out on this topic (yes, we are a little geeky, but then again so are you if you are reading this !).

A Windlass is the tightening of a rope or cable around a pivot point. The plantar fascia acts like a cable between the calcaneus and its distal insertion into the proximal phalanyx at the metatarsal phalangeal joints. When the toes are dorsiflexed (as in forefoot rocker from yesterdays post, see bottom diagram above), the heel and toes SHOULD become approximated, as the plantar fascia shortens from its winding around the metatarsal head, contributing to supination of the foot.

To be accurate, this concept of the Windlass mechanism is quite complex because the dorsiflexion of the great toe also shortens the length of the flexor hallucis brevis.  And we know that the sesamoid bones under the big toe are embedded in its tendon. Their repositioning as the Windlass engages will drive the sesamoids under the metatarsal, elevating it, and shift this joints eccentric axis.  But this is a complex story and post better left for another day.  Simply put, this is a complex joint, do not let anyone fool you otherwise.  Don’t beleive us ? Ask any bunion (or God forbid a fusion) surgery patient how they are doing.  You will get the point then. 

Here’s the link to the article (we know you want to read it ! )

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC385265/

The Windlass Mechanism. Just another fascinating foot fact from The Gait Guys.

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Forefoot Rocker and Premature Heel Rise:

 

Remember the rockers? We did a series on this a few weeks ago. Remember there are three: heel, ankle and forefoot. We are going to concentrate on the forefoot today. As a reminder, forefoot rocker occurs at the 1st metatarsal phalangeal joint (big toe knuckle) as the tibia progresses over the forefoot during forward movement. There are 4 things that SHOULD happen at this point to ensure the heel comes up :

 

1. continued forward momentum  of the body

2. the posterior compartment (primarily the gastroc/soleus group and tibilais posterior) contract to accelerate the rate of forward limb movement.

3. passive tension in the posterior compartment muscles

4  the windlass effect of the plantar fascia (see diagram)

Watch this slow motion video and what do you see? You should see some midfoot collapse and premature heel rise, especially on the right foot. Did you notice the little “bounce” in his step? How about the subtle adduction of his heel, L > R?  Watch it again until you see it. (The bounce is generated by the premature heel lift and premature firing of the calf compartment muscles.  Normally the body mass is further forward of the heel rise event, and thus contraction of the calf generates a more forward directed vector, however, when the heel rise is premature the body mass is still somewhat over the foot.  Thus, if the calf were to fire at this moment, it would cause a vertical body mass movement vector.  When this occurs bilaterally these clients will have a very “bouncy” vertically oriented gait strategy.  This is very inefficient gait when it occurs. Plus there is a dramatic reduction in the pronation phase of gait, so shock absorption is severely reduced.)

Does he have forward progression of the body mass? Yes

Do you think the posterior compartment is actively contracting? Probably too much. Remember the medial gastrocnemius adducts the heel at the end of terminal stance to assist in supination.

Does there appear to be increased passive tension in the posterior compartment? Yes, it appears to be the case !

How is his windlass mechanism? Good but not good enough. (see our next blog post regarding the Windlass)

Premature heel rise… Coming to a midfoot overpronator and people with loss of hip extension near you.

Telling it like it is. We are the Gait guys…..