If you are a sprinter, how you load the forefoot bipod might be a variable for speed or injury. Tendons can change their cross sectional area, if you load them.

Screen Shot 2019-06-10 at 6.17.21 PM.png

Of course this article is not exclusive for sprinters, it pertains to any running sport, even endurance.

Maximum isometric force had increased by 49% and tendon CSA by 17% !
Tendons can change their cross sectional area, if you load them.

Here I show lateral forefoot loading in a heel raise, and a medial forefoot loading in heel raise. This has to be part of the discovery process outlined below. Forefoot types will play into the loading choice, and unequal strength of the medial or lateral calf compartment will also play into the loading choice made. Where do you need to put your strength ? And is the forefoot competent to take that loading challenge ? Meaning, do they have a forefoot valgus? A forefoot supinatus ? These things matter. If you are a sprinter, how you load the forefoot bipod might be a variable of foot type, asymmetrical posterior compartment strength, or foot strike pattern in the frontal plane (search our blog for cross over gait and glute medius targeting strategies for step width) ,or a combination of several or all of the above. These things matter, and why and where you put your strength matters, if you are even aware of where and how you are putting the loads, and why of course. Of course, then there are people like the recent Outside online article that says how you foot strike doesn’t matter, but it does matter. But of course, if you do not know the things we have just mentioned, it is easy to write such an article.

Isometrics are useful, they have their place. In a recent podcast we discussed the place and time to use isometrics, isotonics, eccentrics and concentrics.
One of the goals in a tendinopathy is to restore the tendon stiffness. Isometrics are a safe way to load the muscle tendon complex without engaging a movement that might have to go through a painful arc of movement. With isometrics here is neurologic overspill into the painful arc without having to actually go there.
The key seems to be load. More load seems to get most people further along. Remember, the tendon is often problematic because it is inflammed and cannot provide a stiffness across its expanse. Heavy isometric loading seems to be a huge key for most cases. But, we have to say it here, not everyone fits this mold. Some tendons, in some people, will respond better to eccentrics, and strangely enough, some cases like stretching (perhaps because this is a subset of an eccentric it seems or because there is a range of motion issue in the joint that is a subset of the problem). Now the literature suggests that stretching is foolish, but each case is unique all in its own way, and finding what works for a client is their medicine, regardless of what the literature and research says.
Finding the right load for a given tendon and a right frequency of loading and duraction of loading is also case by case specific. Part of finding the right loading position is a discovery process as well, as noted in the photos above. Finding the fascicles you want to load, and the ones you do not want to load (painful) can be a challenging discovery process for you and your client. Finding the right slice of the pie to load, and the ones not to load takes experimentation. When it is the achilles complex, finding the safe However, if one is looking for a rough template to build from, brief, often, heavy painfree loads is a good template recipe to start with.

Here, in this Geremia et al article, "ultrasound was used to determine Achilles tendon cross-sectional area (CSA), length and elongation as a function of plantar flexion torque during voluntary plantar flexion."
They discovered that, "At the end of the training program, maximum isometric force had increased by 49% and tendon CSA by 17%, but tendon length, maximal tendon elongation and maximal strain were unchanged. Hence, tendon stiffness had increased by 82%, and so had Young’s modulus, by 86%.

Effects of high loading by eccentric triceps surae training on Achilles tendon properties in humans. Jeam Marcel Geremia, Bruno Manfredini Baroni, Maarten Frank Bobbert, Rodrigo Rico Bini, Fabio Juner Lanferdini, Marco Aurélio Vaz
European Journal of Applied Physiology
August 2018, Volume 118, Issue 8, pp 1725–1736

Podcast 123: The Rear foot: Understanding your RearFoot type

Key tag words:
foot types, rearfoot, forefoot, pronation, supination, shoe fit, forefoot varus, forefoot supinatus, rearfoot inversion, ankle rocker, injuries, rehab, corrective exercises

Rearfoot varus and Rearfoot valgus. Knowing the anatomy of your rear foot and its anatomic and functional posturing can lead to many problems in anyone. If you do not know the rearfoot type and posturing, you will not understand the rest of the foot mechanics. Without this knowledge, you will not know the reason for midfoot or forefoot problems, not understand what shoe you are in, or even why the shoe, footbed, orthotic you have chosen is either not fixing your problems, or causing them.  Join us on a journey down the rearfoot rabbit hole over the next hour.  Plus a few funny stories to lighten the biomechanics-heavy dialogue.
 

Show links:
http://traffic.libsyn.com/thegaitguys/pod_123final_cut.mp3

http://thegaitguys.libsyn.com/podcast-123-the-rear-foot-understanding-your-rearfoot-type

Show sponsors:
www.newbalancechicago.com

www.thegaitguys.com
That is our website, and it is all you need to remember. Everything you want, need and wish for is right there on the site.
Interested in our stuff ? Want to buy some of our lectures or our National Shoe Fit program? Click here (thegaitguys.com or thegaitguys.tumblr.com) and you will come to our websites. In the tabs, you will find tabs for STORE, SEMINARS, BOOK etc. We also lecture every 3rd Wednesday of the month on onlineCE.com. We have an extensive catalogued library of our courses there, you can take them any time for a nominal fee (~$20).
 
Our podcast is on iTunes, Soundcloud, and just about every other podcast harbor site, just google "the gait guys podcast", you will find us.
 
Show Notes:

https://www.ncbi.nlm.nih.gov/pubmed/27134364

https://www.ncbi.nlm.nih.gov/pubmed/25364132

RearFoot positions:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3588658/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3990938/

Powers CM, Maffucci R, Hampton S. Rearfoot posture in subjects with patellofemoral pain. J Orthop Sports Phys Ther. 1995 Oct;22(4):155-60.

Power V, Clifford AM. The Effects of Rearfoot Position on Lower Limb Kinematics during Bilateral Squatting in Asymptomatic Individuals with a Pronated Foot Type. J Hum Kinet. 2012 Mar;31:5-15. doi: 10.2478/v10078-012-0001-0. Epub 2012 Apr 3.

Shultz SP, Song J, Kraszewski AP, Hafer JF, Rao S, Backus , Mootanah R, Hillstrom HJ. An Investigation of Structure, Flexibility and Function Variables that Discriminate Asymptomatic Foot Types. J Appl Biomech. 2016 Dec 19:1-25. [Epub ahead of print]

 

Forefoot varus and patellofemoral cartilage damage.

So you just give everyone a FOOT TRIPOD and ANKLE ROCKER exercise and think the world will all be sunshine and rainbows huh ? Beware all you movement wizards, there is far more to it !

"Knowing enough to think you're doing it right, but not enough to know you're doing it wrong." - Neil deGrasse Tyson

So your client has knee pain huh ? Look far and wide, this is a global game amigos.
"Of the 51% of limbs with forefoot varus, 91.3% had medial and 78.3% had lateral PFJ cartilage damage. . . . . this study suggest a relationship between forefoot varus and medial PFJ cartilage damage in older adults"- Lufler et al. (study link below)

*If you do not know your client has a rigid forefoot varus, and they have hip or low back pain and cannot keep their glutes activated and participating in movements, how long are you going to fail your client ? The forefoot varus may need addressed because of the excessive, abrupt degree of internal spin on the limb.

If you are truly going to treat people, people who move (yes, that means everyone !), you have to know feet and gait, BOTH. Your knowledge must go far past rudimentary knowledge of:
- high / low arch
- flat feet
- prontation and supination
- orthotics and footbeds

You will have to know your foot types, you will have to understand shoe anatomy, foot anatomy, flexible semi-flexible and rigid foot types, compensated and uncompensated foot types, and of course know how each of these responds under various loading responses. Forefoot varus will load differently in cutting sports than in sagittal locomotion such as walking and running (both of which are different even in themselves despite both being sagittal). A foot that looks like it has a flat collapsed arch has far more to it than that, and thus remedy and intervention MUST go far beyond rudimentary interventions like a "stability shoe" or orthotic. Are you practicing, coaching, training and being part of your client's solution, or are you part of the problem ? If you want to get better at this stuff, we cover it all in our several hour (very difficult for some) National Shoe Fit program (the link is on our website if you wish to become a foot/gait/shoe jediwww.thegaitguys.com). Do not be mistaken, this is far more than "shoe Fit". To know how to properly shoe fit someone, you have to know the foot types and how they compensate, load, and respond. Without this knowledge, you are just another bump in the "road of problems" without ample solutions.

- Dr. Shawn Allen, one of the gait guys

The Association of Forefoot Varus Deformity with Patellofemoral Cartilage Damage in Older Adult Cadavers. Lufler, Stefanik, Niu, Sawyer, Hoagland, Gross http://onlinelibrary.wiley.com/doi/10.1002/ar.23524/full

images courtesy of aaronswansonpt.com and studyblue.com

SoftScience “The Terrain Ultra Lyte” shoe update:  Introducing “The Terrain Ultra Lyte”.  Fresh off the UPS truck today 
and just unboxed ! Uber excited. Wearing them right now. Dang, zero drop
 with good cush. I could run in these babies ! And I will just to try, 
even thought that is likely not their intended purpose.  Gorgeous roomy 
toe box. True to fit. These feel like a favorite pair of worn in 
favorite leather gloves …  they are soft cotton canvass right out of
 the box.  I don’t think i even need to wait a few days, they
 should have a label that says “pre-worn in”. I may have just found yet 
another new favorite weekend casual shoes, I will save my Altra 
Everyday’s for work. I can see where the thinking came when the partners
 brought their wisdom over from Crocs (only the best parts were brought,
 the materials, from what i can see).    Removable, washable Trileon™ insole, non-marking, slip-resistant outsole  Ultra lightweight, a pair in size 10 weighs just 1.6 lbs. (that is per pair !)    *Welcome to Soft Science. one of our Podcast sponsors. Because we believe in them.     Update one day later:     Some have been asking about this shoe. I 
think they have done something unique here. This shoe is about 6 oz, 
yes, that is seriously uber light. That means there is no room for 
stabilizing rigidity factors in this shoe. It appears to be a well 
thought out “outsole” and a soft cotton canvas upper. That is it. If you
 need control, this shoe may not be for you. The outsole however offers a
 nice wide foot print with some flare of the sole out from the foot 
(look at their website, look at the shoe from behind), and that in 
itself offers stabilizing over something compared to like a glove type 
shoe.   Now, on to the insole:  I know what the website says, a 
“minimal heal to toe elevation”. I emailed the guru over as Soft 
Science. I have been told they are zero drop and after wearing i believe
 they are, and if not, maybe a millimeter ? I have sensitive feet, I 
wear zero drop all day long at work because I can. Not everyone can and 
this is important to note.  I do not have any info outsole thickness 
of this particular shoe, the foot does recede somewhat into the outsole 
that you see, so there is not a tremendous amount of stack height as 
portrayed in photos, some of that is the outsole lipping up to grab onto
 the shoe’s upper.   TRileon Insole:There is a VERY mild arch 
contour, not as much as in crocs (as one person asked) but it is present
 and mild. If you have a flatter arch, you will feel it, but, Trileon is
 uber cush so it is not offending at all. If you have a normal arch 
posture, you may not even notice it, it is that subtle.   Insole: 
there feels like a 1-2 degree or 1-2 mm varus forefoot post, i have 
pretty sensitive feet and can tell these things readily, i may choose to
 grind this down on the insole, it wouldn’t take much to do this. If you
 take out the insole and put it on a hard floor and stand on it, you 
will notice the subtle forefoot varus posting of the foam. And if you 
put the insole in your hands and pinch finger tips together at the 1st 
metatarsal head and 5th met. head you will notice the thickness 
difference. * It is not much, but it is there. Some people can really 
benefit from it since many feet are have a slight FF varus. Some may not
 notice it at all. I did notice it because my forefoot is not varus’d at
 all.  I noted it less so when the insole was in the shoe so it may be 
off setting a slight depression in the outsole shell. I am not sure, so 
do not quote me on this. For most folks, this is “princess and the pea” 
subtle jibber jab talk and is not worthy of noting.  But we are shoe 
geeks and some of you want to know about peas.  To be clear, I like 
this shoe so far, very much actually. It will be on my feet all week and
 all weekend……..many weekends.  Soft, uber light, no break in, zero 
drop, good looks, minimal, wide platform, ….. things i like and things
 that are important to me. The question is, “is it for you ?” That is up
 to you.  Nice work Soft Science.  -Dr. Allen    http://www.softscience.com/mens/the-terrain-ultra-lyte.html

SoftScience “The Terrain Ultra Lyte” shoe update:

Introducing “The Terrain Ultra Lyte”.  Fresh off the UPS truck today and just unboxed ! Uber excited. Wearing them right now. Dang, zero drop with good cush. I could run in these babies ! And I will just to try, even thought that is likely not their intended purpose.  Gorgeous roomy toe box. True to fit. These feel like a favorite pair of worn in favorite leather gloves …  they are soft cotton canvass right out of the box.  I don’t think i even need to wait a few days, they should have a label that says “pre-worn in”. I may have just found yet another new favorite weekend casual shoes, I will save my Altra Everyday’s for work. I can see where the thinking came when the partners brought their wisdom over from Crocs (only the best parts were brought, the materials, from what i can see).  
Removable, washable Trileon™ insole, non-marking, slip-resistant outsole
Ultra lightweight, a pair in size 10 weighs just 1.6 lbs. (that is per pair !)

*Welcome to Soft Science. one of our Podcast sponsors. Because we believe in them.

Update one day later:

Some have been asking about this shoe. I think they have done something unique here. This shoe is about 6 oz, yes, that is seriously uber light. That means there is no room for stabilizing rigidity factors in this shoe. It appears to be a well thought out “outsole” and a soft cotton canvas upper. That is it. If you need control, this shoe may not be for you. The outsole however offers a nice wide foot print with some flare of the sole out from the foot (look at their website, look at the shoe from behind), and that in itself offers stabilizing over something compared to like a glove type shoe.
Now, on to the insole:
I know what the website says, a “minimal heal to toe elevation”. I emailed the guru over as Soft Science. I have been told they are zero drop and after wearing i believe they are, and if not, maybe a millimeter ? I have sensitive feet, I wear zero drop all day long at work because I can. Not everyone can and this is important to note.
I do not have any info outsole thickness of this particular shoe, the foot does recede somewhat into the outsole that you see, so there is not a tremendous amount of stack height as portrayed in photos, some of that is the outsole lipping up to grab onto the shoe’s upper.
TRileon Insole:There is a VERY mild arch contour, not as much as in crocs (as one person asked) but it is present and mild. If you have a flatter arch, you will feel it, but, Trileon is uber cush so it is not offending at all. If you have a normal arch posture, you may not even notice it, it is that subtle.
Insole: there feels like a 1-2 degree or 1-2 mm varus forefoot post, i have pretty sensitive feet and can tell these things readily, i may choose to grind this down on the insole, it wouldn’t take much to do this. If you take out the insole and put it on a hard floor and stand on it, you will notice the subtle forefoot varus posting of the foam. And if you put the insole in your hands and pinch finger tips together at the 1st metatarsal head and 5th met. head you will notice the thickness difference. * It is not much, but it is there. Some people can really benefit from it since many feet are have a slight FF varus. Some may not notice it at all. I did notice it because my forefoot is not varus’d at all.  I noted it less so when the insole was in the shoe so it may be off setting a slight depression in the outsole shell. I am not sure, so do not quote me on this. For most folks, this is “princess and the pea” subtle jibber jab talk and is not worthy of noting.  But we are shoe geeks and some of you want to know about peas.
To be clear, I like this shoe so far, very much actually. It will be on my feet all week and all weekend……..many weekends.  Soft, uber light, no break in, zero drop, good looks, minimal, wide platform, ….. things i like and things that are important to me. The question is, “is it for you ?” That is up to you.  Nice work Soft Science.
-Dr. Allen

http://www.softscience.com/mens/the-terrain-ultra-lyte.html

Fore foot types: Differences between forefoot varus and forefoot supinatus.  Certainly this can be a contraversial topic. Perhaps this will help clear up some questions.  Supination of the forefoot that develops with adult acquired flatfoot is defined as forefoot supinatus. This deformity is an acquired soft tissue adaptation in which the forefoot is inverted on the rearfoot. Forefoot supinatus is a reducible deformity. Forefoot supinatus can mimic, and often be mistaken for, a forefoot varus. A forefoot varus differs from forefoot supinatus in that a forefoot varus is a congenital osseous deformity that induces subtalar joint pronation, whereas forefoot supinatus is acquired and develops because of subtalar joint pronation (1).  A Forefoot Varus induces STJ pronation whereas a Forefoot Supinatus is created because of STJ pronation (2).  As the foot experiences increased subtalar joint (STJ) pronation moments during weightbearing activities (as in forefoot supinatus) , the medial metatarsal rays will be subjected to increased dorsiflexion moments and the lateral metatarsal rays will be subjected to decreased dorsiflexion moments. Over time, this increase in STJ pronation moments will tend to cause a lengthening of the plantar ligaments and medial fibers of the central component of the plantar aponeurosis and a shortening of the dorsal ligaments in the medial longitudinal arch. As a result, the influence of increased STJ pronation moments occurring over time during weightbearing activities will tend to cause the following (3):  1. An increase in inverted forefoot deformity. 2. A decrease in everted forefoot deformity. 3. A change in everted forefoot deformity to either a perpendicular forefoot to rearfoot relationship or to an inverted forefoot deformity.  More on the forefoot tomorrow evening on  onlinece.com:  Biomechanics 309. Join us!  1. Clin Podiatr Med Surg. 2014 Jul;31(3):405-13. doi: 10.1016/j.cpm.2014.03.009. Forefoot supinatus. Evans EL1, Catanzariti AR2.  2.  https://kenva.wordpress.com/…/…/forefoot-varus-or-supinatus/   3.  http://www.podiatry-arena.com/podiatry-forum/showthread.php…

Fore foot types: Differences between forefoot varus and forefoot supinatus.

Certainly this can be a contraversial topic. Perhaps this will help clear up some questions.

Supination of the forefoot that develops with adult acquired flatfoot is defined as forefoot supinatus. This deformity is an acquired soft tissue adaptation in which the forefoot is inverted on the rearfoot. Forefoot supinatus is a reducible deformity. Forefoot supinatus can mimic, and often be mistaken for, a forefoot varus. A forefoot varus differs from forefoot supinatus in that a forefoot varus is a congenital osseous deformity that induces subtalar joint pronation, whereas forefoot supinatus is acquired and develops because of subtalar joint pronation (1).

A Forefoot Varus induces STJ pronation whereas a Forefoot Supinatus is created because of STJ pronation (2).

As the foot experiences increased subtalar joint (STJ) pronation moments during weightbearing activities (as in forefoot supinatus) , the medial metatarsal rays will be subjected to increased dorsiflexion moments and the lateral metatarsal rays will be subjected to decreased dorsiflexion moments. Over time, this increase in STJ pronation moments will tend to cause a lengthening of the plantar ligaments and medial fibers of the central component of the plantar aponeurosis and a shortening of the dorsal ligaments in the medial longitudinal arch. As a result, the influence of increased STJ pronation moments occurring over time during weightbearing activities will tend to cause the following (3):

1. An increase in inverted forefoot deformity.
2. A decrease in everted forefoot deformity.
3. A change in everted forefoot deformity to either a perpendicular forefoot to rearfoot relationship or to an inverted forefoot deformity.

More on the forefoot tomorrow evening on onlinece.com: Biomechanics 309. Join us!

1. Clin Podiatr Med Surg. 2014 Jul;31(3):405-13. doi: 10.1016/j.cpm.2014.03.009. Forefoot supinatus. Evans EL1, Catanzariti AR2.

2. https://kenva.wordpress.com/…/…/forefoot-varus-or-supinatus/

3. http://www.podiatry-arena.com/podiatry-forum/showthread.php…

Forefoot Varus or Forefoot Supinatus?   Forefoot varus is a fixed, frontal plane deformity where the forefoot is inverted with respect to the rearfoot. Forefoot varus is normal in early childhood, but should not persist past 6 years of age (i.e. when developmental valgus rotation of forefoot on rearfoot is complete, and plantar aspects of fore- and rearfoot become parallel to, and on same plane as, one another (1)  Forefoot supinatus is the supination of the forefoot that develops with adult acquired flatfoot deformity. This is an acquired soft tissue adaptation in which the forefoot is inverted on the rearfoot. Forefoot supinatus is a reducible deformity. Forefoot supinatus can mimic, and often be mistaken for, a forefoot varus. (2)  A forefoot varus differs from forefoot supinatus in that a forefoot varus is a congenital osseous where a forefoot supinatus is acquired and develops because of subtalar joint pronation.  “Interestingly, only internal rotation of the hip was increased in subjects with FV – no differences were present in hip adduction and knee abduction between subjects with and without FV. The authors nevertheless conclude that FV causes significant changes in mechanics of proximal segments in the lower extremity and speculate that during high-speed weight-bearing tasks such as running, the effects of FV on proximal segments in the kinetic chain might be more pronounced.”  We wonder if the folks in this study had a true forefoot varus, or actually a forefoot supinatus (3).     The Gait Guys   1. Illustrated Dictionary of Podiatry and Foot Science by Jean Mooney © 2009 Elsevier Limited.  2. Evans EL1, Catanzariti AR2. Forefoot supinatus.  Clin Podiatr Med Surg. 2014 Jul;31(3):405-13. doi: 10.1016/j.cpm.2014.03.009.  3. Scattone Silva R1, Maciel CD2, Serrão FV3. The effects of forefoot varus on hip and knee kinematics during single-leg squat. Man Ther. 2015 Feb;20(1):79-83. doi: 10.1016/j.math.2014.07.001. Epub 2014 Jul 12.

Forefoot Varus or Forefoot Supinatus?

Forefoot varus is a fixed, frontal plane deformity where the forefoot is inverted with respect to the rearfoot. Forefoot varus is normal in early childhood, but should not persist past 6 years of age (i.e. when developmental valgus rotation of forefoot on rearfoot is complete, and plantar aspects of fore- and rearfoot become parallel to, and on same plane as, one another (1)

Forefoot supinatus is the supination of the forefoot that develops with adult acquired flatfoot deformity. This is an acquired soft tissue adaptation in which the forefoot is inverted on the rearfoot. Forefoot supinatus is a reducible deformity. Forefoot supinatus can mimic, and often be mistaken for, a forefoot varus. (2)

A forefoot varus differs from forefoot supinatus in that a forefoot varus is a congenital osseous where a forefoot supinatus is acquired and develops because of subtalar joint pronation.

“Interestingly, only internal rotation of the hip was increased in subjects with FV – no differences were present in hip adduction and knee abduction between subjects with and without FV. The authors nevertheless conclude that FV causes significant changes in mechanics of proximal segments in the lower extremity and speculate that during high-speed weight-bearing tasks such as running, the effects of FV on proximal segments in the kinetic chain might be more pronounced.”

We wonder if the folks in this study had a true forefoot varus, or actually a forefoot supinatus (3).


The Gait Guys


1. Illustrated Dictionary of Podiatry and Foot Science by Jean Mooney © 2009 Elsevier Limited.

2. Evans EL1, Catanzariti AR2. Forefoot supinatus.
Clin Podiatr Med Surg. 2014 Jul;31(3):405-13. doi: 10.1016/j.cpm.2014.03.009.

3. Scattone Silva R1, Maciel CD2, Serrão FV3. The effects of forefoot varus on hip and knee kinematics during single-leg squat. Man Ther. 2015 Feb;20(1):79-83. doi: 10.1016/j.math.2014.07.001. Epub 2014 Jul 12.

Forefoot Varus Anyone?   Forefoot varus appears to move the center of gravity medially while walking. Nothing earthshaking here, but nice to see the support of the literature.  “The most medial CoP of the row and CoP% detected increased medial CoP deviation in FV ≥ 8°, and may be applied to other clinical conditions where rearfoot angle and CoP of the array after initial heel contact cannot detect significant differences.”  We will be talking about foot types this week on  onlinece.com ; Wednesday 8 EST, 7 CST, 6MST, 5 PST Biomechanics 314. Hope to see you there!  J Formos Med Assoc. 2015 May 5. pii: S0929-6646(15)00132-1. doi: 10.1016/j.jfma.2015.03.004. [Epub ahead of print] Analysis of medial deviation of center of pressure after initial heel contact in forefoot varus.  picture from:  http://forums.teamestrogen.com/showthread.php?t=46901

Forefoot Varus Anyone?

Forefoot varus appears to move the center of gravity medially while walking. Nothing earthshaking here, but nice to see the support of the literature.

“The most medial CoP of the row and CoP% detected increased medial CoP deviation in FV ≥ 8°, and may be applied to other clinical conditions where rearfoot angle and CoP of the array after initial heel contact cannot detect significant differences.”

We will be talking about foot types this week on onlinece.com; Wednesday 8 EST, 7 CST, 6MST, 5 PST Biomechanics 314. Hope to see you there!

J Formos Med Assoc. 2015 May 5. pii: S0929-6646(15)00132-1. doi: 10.1016/j.jfma.2015.03.004. [Epub ahead of print]
Analysis of medial deviation of center of pressure after initial heel contact in forefoot varus.

picture from: http://forums.teamestrogen.com/showthread.php?t=46901

Some stuff you need to know about running spikes.  I see many track runners in my office, from middle school all the way into the USA Masters Division.  A few years ago one of the top USA Masters Milers came to see me on Friday before heading off to a national meet. He showed me some of his spikes (see pics above) and complained the there was something off on the spikes on the left, the Nike Mambas.  The shoe to the right is the Nike Zoom Miler.   You need to understand a bit of the physics of running turns to understand what is missing for this runner in this pair of spikes.  Things do change if you are running on a sloped track, but those are only found indoors and are not all that common to run on for most folks so we will stick with the thinking on flat tracks.  What you should be able to easily detect is that the Nike Mamba’s are missing the lateral 5th metatarsal forefoot spike on the cleat plate.  And you need to then realize that this is the right shoe, so it is the outside foot/leg on the track. It is the foot that will be pushing off harder from the outside on the turns to keep the centripetal forces of running a curve from allowing the runner to fall off the curve into the outer lanes. This right foot will always be pushing from outside to inside to maintain the body’s progression in the desired lane, when running the curves.  Think about it for a minute. In order to run in a circle, or a curve in this situation, the outside foot always has the tendancy to be more inverted to keep foot contact on the ground. This is where a Forefoot varus MIGHT come in handy ! This means the foot will be tipped to the outside a little, because of the curve and because the body will be leaning into the center of the track on the curves. Thus the foot and shoe will be relying on more lateral foot pressures to drive the body mass back into the lane since centripetal forces will always be driving you laterally out of the lane.  Thus, the lateral spikes on the right foot must be accommodating.  In the case of the Mamba shoe. there is only a sheet of black hard plastic over the midshaft-head of the 5th Metatarsal on the lateral foot. It is no wonder the runner was feeling like he was slipping on the turns (the front of the midfoot was not anchored to the ground, only the forefoot due to the spikes in that location). You can see clear evidence of the lateral slipping in the picture. Can you see the orange/brown patch where he was slipping ? A spike there in that area would have been wonderful.  Slipping is a power leak and a risk for injury.  If the foot is trying to gain purchase into/onto the track with the foot inverted there needs to be traction at that lateral foot, what is referred to as the Lateral Column.  You can see why the Nike Zoom Miler was a better choice, there is a nice spike placement under the lateral foot for just this measure, and there is no evidence of slippage wear.  He told me that the Mamba was a steeplechase designed shoe but we still both felt that the issue remained relevant even in that event. The Nike website however states that “the Nike Zoom Mamba Men’s Track and Field Shoe is perfect for the 800-5000m track athlete” so we think they have missed an issue here in our opinion.  I could make a better case for the Mambas if  they were for a 100m straight run but I would still like a 5th metatarsal /lateral spike where there isn’t one.  I will occasionally file spikes to get the perfect feel for the athlete.  It is usually the 5th metatarsal and 1st metatarsal spikes I mess with, merely to help hone the athletes feel on the track. The problem is that each track has a different feel so it is less of an occurrence in recent years.  It is good to know your shoes, it is good to know your physics. It is great to know them both and melt them together to solve problems.  Not all spikes are created equal, not all tracks are the same, not all events are the same and certainly not all feet and the athlete’s who own them are the same.  And on the topic of Forefoot Foot types, both the forefoot varus and forefoot valgus foot might have a problem with the Mamba’s depending on their strength, skill and strategies for ground purchase.  Hopefully your shoe store and your track and cross country coaches know these issues. You might want to bring this blog post to their attention however, just in case.   Dr. Shawn Allen

Some stuff you need to know about running spikes.

I see many track runners in my office, from middle school all the way into the USA Masters Division.  A few years ago one of the top USA Masters Milers came to see me on Friday before heading off to a national meet. He showed me some of his spikes (see pics above) and complained the there was something off on the spikes on the left, the Nike Mambas.  The shoe to the right is the Nike Zoom Miler.

You need to understand a bit of the physics of running turns to understand what is missing for this runner in this pair of spikes.  Things do change if you are running on a sloped track, but those are only found indoors and are not all that common to run on for most folks so we will stick with the thinking on flat tracks.

What you should be able to easily detect is that the Nike Mamba’s are missing the lateral 5th metatarsal forefoot spike on the cleat plate.  And you need to then realize that this is the right shoe, so it is the outside foot/leg on the track. It is the foot that will be pushing off harder from the outside on the turns to keep the centripetal forces of running a curve from allowing the runner to fall off the curve into the outer lanes. This right foot will always be pushing from outside to inside to maintain the body’s progression in the desired lane, when running the curves.

Think about it for a minute. In order to run in a circle, or a curve in this situation, the outside foot always has the tendancy to be more inverted to keep foot contact on the ground. This is where a Forefoot varus MIGHT come in handy ! This means the foot will be tipped to the outside a little, because of the curve and because the body will be leaning into the center of the track on the curves. Thus the foot and shoe will be relying on more lateral foot pressures to drive the body mass back into the lane since centripetal forces will always be driving you laterally out of the lane.  Thus, the lateral spikes on the right foot must be accommodating.  In the case of the Mamba shoe. there is only a sheet of black hard plastic over the midshaft-head of the 5th Metatarsal on the lateral foot. It is no wonder the runner was feeling like he was slipping on the turns (the front of the midfoot was not anchored to the ground, only the forefoot due to the spikes in that location). You can see clear evidence of the lateral slipping in the picture. Can you see the orange/brown patch where he was slipping ? A spike there in that area would have been wonderful.  Slipping is a power leak and a risk for injury.  If the foot is trying to gain purchase into/onto the track with the foot inverted there needs to be traction at that lateral foot, what is referred to as the Lateral Column.  You can see why the Nike Zoom Miler was a better choice, there is a nice spike placement under the lateral foot for just this measure, and there is no evidence of slippage wear.  He told me that the Mamba was a steeplechase designed shoe but we still both felt that the issue remained relevant even in that event. The Nike website however states that “the Nike Zoom Mamba Men’s Track and Field Shoe is perfect for the 800-5000m track athlete” so we think they have missed an issue here in our opinion.

I could make a better case for the Mambas if  they were for a 100m straight run but I would still like a 5th metatarsal /lateral spike where there isn’t one.  I will occasionally file spikes to get the perfect feel for the athlete.  It is usually the 5th metatarsal and 1st metatarsal spikes I mess with, merely to help hone the athletes feel on the track. The problem is that each track has a different feel so it is less of an occurrence in recent years.

It is good to know your shoes, it is good to know your physics. It is great to know them both and melt them together to solve problems.  Not all spikes are created equal, not all tracks are the same, not all events are the same and certainly not all feet and the athlete’s who own them are the same.  And on the topic of Forefoot Foot types, both the forefoot varus and forefoot valgus foot might have a problem with the Mamba’s depending on their strength, skill and strategies for ground purchase.  Hopefully your shoe store and your track and cross country coaches know these issues. You might want to bring this blog post to their attention however, just in case.

Dr. Shawn Allen

pronation

Here is an abstract you should look at.
Br J Sports Med. 2014 Mar;48(6):440-7. doi: 10.1136/bjsports-2013-092202. Epub 2013 Jun 13.

Foot pronation is not associated with increased injury risk in novice runners wearing a neutral shoe: a 1-year prospective cohort study.

http://www.ncbi.nlm.nih.gov/pubmed/23766439
And then there is this article we came cross at Runner’s World online. Here is the article “Five things i learned about buying running shoes”.
In all fairness we do not think the article was meant to teach or say much, but we do feel like it robbed 2 minutes of our productive life, at least it was entertaining.
So it is our turn now, let us serve you some real meat.  Here are some loose thoughts on why shoe fit and research has limitations in our opinion, mostly commentary on the first article and why you need to takes its commentary with a grain of salt.
The problem lies in the knowledge base. Most researchers just do not seem to know enough about the foot types , osseous torsions, the kinetic chain, and the like, to do an ALL ENCOMPASSING study. Plus, such a study would be an infinite nightmare. This is where a clinician is needed, to draw upon all of the issues at hand, not just some of the issues.  
For example, in this study, they just looked at arch heights and their determination as to whether the foot was pronating to a degree  (foot-posture index and categorized into highly supinated (n=53), supinated (n=369), neutral (n=1292), pronated (n=122) or highly pronated (n=18).)
No where did they talk about foot types such as the very common forefoot variants of varus and valgus let along their compensated and uncompensated forms. No where were there discussions of tibial or femoral torsion or the possibly necessary foot pronation needs to bring the knee joint back to the sagittal plane. Plus, just because a foot is flat, doesn’t truly mean it is over pronated. It may be flat because of genetics, we have talked about genetic trends here in previous blog posts.  We see plenty of flat competent feet in our clinics. The may appear flat or over pronated , but that is not the case for many people. The FUNCTION must be examined, and this does not come from visual inspection or from gait analysis video. We always say “what you see in someones gait or foot function is often their compensation around other issues, it is not their problem”.
Shawn and Ivo, the gait guys
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Did you see this in our recent blog post here ? a reader made us look closer. Did you catch it ?
The clients right foot appears to have a dropped 1st met head. (we hate this term, because it is not accurate and is a sloppy clinical description). In this still photo it appears plantarflexed.  But in this video, consider the descended 1st met head as due to the disuse or weakness of the EHL muscle (extensor hallucis longus) of the 1st toe. Or, is this in fact a compensated forefoot varus ? Sure looks like it. But with all that anterior compartment weakness (as we discussed in the previous blog post link above) it could just be a mirage. In the photo above, in a normal foot the rearfoot plane (greenline) should parallel the forefoot line (orange line). In this case, in this actively postured foot (thus some inaccuracy here, we are merely making a teaching point from the photo) the upslope of the orange line suggests a forefoot varus. This would be true if the first Metatarsal head also was on this line, but you can see that it has its own idea. This represents, in theory (regarding this photo), a compensated forefoot varus. But remember, this client is  holding the foot actively in this posture. A true hands on assessment is needed to truly define a Forefoot varus, and whether it is anatomic, flexible, rigid or in many cases, just a learned functional posturing from weakness of the flexor/extensor pairing of the 1st metatarsal complex or from other weaknesses of the other forefoot evertors.  It gets complicated as you can see.

As always, knowledge of the anatomy and functional anatomy allows for observation, and observation leads to understanding, which leads to answers and then remedy implementation. Our thoughts, knowing the case, is that this is a functional appearance illusion of a compensated forefoot varus due to the EHL, EDL and tibialis anterior weakness (anterior compartment) and how they play together with the flexors. One must be sure to assess the EHL when examining the foot. Test all of the muscles one by one.  We have been talking about toe extensors for a long time, they can be a paramount steering wheel for the forefoot and arch posture. Podcast 71 talks about this Forefoot varus, and you should care.
In a 2009 study by Reynard et al they concluded: 

  • “The activity of extensor digitorum longus muscle during the swing phase of gait is important to balance the foot in the frontal plane. The activation of that muscle should be included in rehabilitation programs.” (1)

here is the video again.

Have a burning desire to learn more about forefoot varus, here are 25 blog post links from our last few years. And/or you can take our National Shoe Fit program (downloadable links below).

Knowing what you are seeing during your exam and gait analysis can only truly come from coupling your observations with a clinical exam.  Anything less is speculation and guess work.  It is gambling, and this is not Vegas baby, this is someone’s health.

Shawn and Ivo, The Gait Guys

________________

National Shoe Fit Certification Program:

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

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

1. Foot (Edinb). 2009 Jun;19(2):69-74. Epub 2008 Dec 31. Foot varus in stroke patients: muscular activity of extensor digitorum longus during the swing phase of gait.  Reynard F, Dériaz O, Bergeau J.

Other web based Gait Guys lectures:

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

Podcast 71: Forefoot Varus, Big Toe Problems & Charlie Horses"

*Show sponsor: www.newbalancechicago.com

Lems Shoes.  www.lemsshoes.comMention GAIT15 at check out for a 15% discount through August 31st, 2014.

A. Link to our server: 

Direct Download: 

http://traffic.libsyn.com/thegaitguys/pod_72final.mp3

Permalink: http://thegaitguys.libsyn.com/podcast-71

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:

1. American College of Cardiology. Running out your healthy heart. How much exercise is too much ?

Running for 7 minutes a day cuts risk of death by 30%, study says
http://wgntv.com/2014/07/29/running-for-7-minutes-a-day-cuts-risk-of-death-by-30-study-says/
 
2. The history of “Charlie Horses”
 
3. A runner with strange shin bruises.  
from : Joy 
Hi, I’m a great follower of your blog - fascinating stuff! I was wondering if I could ask you a quick question as nobody I’ve spoken to has been able to help:

I’ve been getting bruises that appear on my shin during running. They don’t hurt, I’m just wary of ignoring what could be a warning sign. Have you ever come across this before? (It’s mainly the spot where I had a tibial stress fracture last year, but I also get a few other apparently spontaneous bruises on my lower legs.)
4. Is that a forefoot varus or are you just happy to see me ?
Functional vs Anatomic vs. Compensated forefoot varus foot postures. A loose discussion.
5. A reader’s pet peeve about shoe store “gait analysis”.
6. Thoughts on pronation and the like.
7. Case study:  First toe fusion and implications long and short term.
“I had a patient today with an MTP fusion of his great toe after adverse complications from a bunionectomy.  Do you have any recommendations for gait training when great toe dorsiflexion is no longer an option?  He is currently compensating by externally rotating his foot and overpronating.  I’m thinking through it and  I know he has to gain the motion elsewhere to help normalize his gait as much as possible, so possibly gaining ankle dorsiflexion and hip extension.  Just wondering if you have any tips to share or articles to point me to for further ideas.  Continuing my research now.  I’m a relatively new grad and this is my first patient I’m seeing with this fusion. Many thanks

Podcast 69: Advanced Arm Swing Concepts, Compensation Patterns and more

Plus: Foot Arch Pathomechanics, Knee Pivot Shift and Sesamoiditis and more !

A. Link to our server: 

http://traffic.libsyn.com/thegaitguys/pod_70ff.mp3

Direct Download: http://thegaitguys.libsyn.com/podcast-70

Permalink: 

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:

1. “Compensation depends on the interplay of multiple factors: The availability of a compensatory response, the cost of compensation, and the stability of the system being perturbed.”
What happens when we change the length of one leg? How do we compensate? Here is a look at the short term consequences of a newly acquired leg length difference.
http://www.ncbi.nlm.nih.gov/pubmed/24857934
2. Medial Longitudinal Arch Mechanics Before and After a 45 Minute Run
http://www.japmaonline.org/doi/abs/10.7547/12-106.1

3. Several months ago we talked about the pivot-shift phenomenon. It is frequently missed clinically because it can be a tricky hands on assessment of the knee joint. In this article “ACL-deficient patients adopted the … .* Remember: what you see in their gait is not their problem, it is their strategy around their problem.
http://www.clinbiomech.com/article/S0268-0033(10)00264-0/abstract

4.Do you know the difference between a forefoot supinatus and a forefoot varus?
"A forefoot varus differs from forefoot supinatus in that a forefoot varus is a congenital osseous deformity that induces subtalar joint pronation, whereas forefoot supinatus is acquired and develops because of subtalar joint pronation. ”
http://www.ncbi.nlm.nih.gov/pubmed/24980930

5. Pubmed abstract link: http://www.ncbi.nlm.nih.gov/pubmed/24865637
Gait Posture. 2014 Jun;40(2):321-6. Epub 2014 May 6.
Arm swing in human walking: What is their drive?
Goudriaan M, Jonkers I, van Dieen JH, Bruijn SM

6. This is Your Brain On Guitar
http://www.the-open-mind.com/this-is-your-brain-on-guitar/

Saucony: Line Running and Crossing Over 
 We are big fans of the Saucony line of shoes. We have recommended them to our novice and serious runners for decades now. Currently one of our favorite shoes for our runners is the Saucony Mirage, a beautiful 4mm ramp shoe with no bells and whistles.  It is as close to a perfect zero drop that  you will find without going zero, in our opinion.  That is not to say there are not other great 4mm shoes out there, the Brooks Cadence and the New balance minimus are other beautiful 4mm’s out there.  The Mirage has never failed a single client of ours.   
 This was a photo we screen captured from the Saucony Facebook page (we hope that for the sake of educating all runners and athletes that we can borrow this picture for this blog post, please contact us if you would like us to remove it). It is a good page, you should follow it as well.  This picture shows not only a nice shoe but something that we have been talking about forever.  The cross over; this runner is running in such a line that it could be argued that the feet are crossing the mid line. In this case, is the line queuing the runner to strike the line ? Careful of subconscious queues when you run, lines are like targets for the eyes and brain.  One thing we like to do with our runners is to use the line as training however, a form of behavioral modification.  When you do a track workout, use the line underneath you, but keep the feet on either side of the line so that you learn to create that little bit of limb /hip abduction that helps to facilitate the hip abductor muscles.  This will do several things, (and you can do a search here on our blog for all these things), it will reduce the reflexive tightening of the ITBand (pay attention all you chronic IT band foam rolling addicts !), it will facilitate less frontal plane pelvis sway, optimal stacking of the lower limb joints, cleaner patellofemoral tracking and help to reduce excessive pronation /internal limb spin effects.   
 There is really nothing negative about correcting your cross over, IF it truly needs correcting.  That is the key question.  Some people may have anatomic reasons as to why the cross over is their norm, but you have to know  your anatomy, biomechanics and neuromechanics and bring them together into a competent clinical examination to know when the correction will lead to optimal gait and when it will drive suboptimal gait. Just because you see it and think it is bad, does not make it so.   
 New to this cross over stuff ? Head over to the search box here on our blog and type in “cross over” or “cross over gait” and you will find dozens of articles and some great videos we have done to help you better grasp it.  
 * you will also note that this runner is in an excessive lateral forefoot strike posturing.  This means that excessive and abrupt prontation will have to follow through the mid-forefoot in order to get the medial foot tripod down and engaged.  The question is however, is what you are seeing a product of the steep limb angle from the cross over, or does this runner have a forefoot varus (functional or anatomic, rigid or flexible)?  Are the peronei muscles weak, making pre-contact foot/ankle eversion less than optimal ? This is an important point, and your clinical examination will define that right away … . . if you know what these things are.  And if you don’t ? Well, you have found the right blog, one with a SEARCH box. Type in “forefoot varus”, if you want to open up the rabbit hole and climb down it … . . we dare ya ! :-)

Saucony: Line Running and Crossing Over

We are big fans of the Saucony line of shoes. We have recommended them to our novice and serious runners for decades now. Currently one of our favorite shoes for our runners is the Saucony Mirage, a beautiful 4mm ramp shoe with no bells and whistles.  It is as close to a perfect zero drop that  you will find without going zero, in our opinion.  That is not to say there are not other great 4mm shoes out there, the Brooks Cadence and the New balance minimus are other beautiful 4mm’s out there.  The Mirage has never failed a single client of ours.  

This was a photo we screen captured from the Saucony Facebook page (we hope that for the sake of educating all runners and athletes that we can borrow this picture for this blog post, please contact us if you would like us to remove it). It is a good page, you should follow it as well.  This picture shows not only a nice shoe but something that we have been talking about forever.  The cross over; this runner is running in such a line that it could be argued that the feet are crossing the mid line. In this case, is the line queuing the runner to strike the line ? Careful of subconscious queues when you run, lines are like targets for the eyes and brain.  One thing we like to do with our runners is to use the line as training however, a form of behavioral modification.  When you do a track workout, use the line underneath you, but keep the feet on either side of the line so that you learn to create that little bit of limb /hip abduction that helps to facilitate the hip abductor muscles.  This will do several things, (and you can do a search here on our blog for all these things), it will reduce the reflexive tightening of the ITBand (pay attention all you chronic IT band foam rolling addicts !), it will facilitate less frontal plane pelvis sway, optimal stacking of the lower limb joints, cleaner patellofemoral tracking and help to reduce excessive pronation /internal limb spin effects.  

There is really nothing negative about correcting your cross over, IF it truly needs correcting.  That is the key question.  Some people may have anatomic reasons as to why the cross over is their norm, but you have to know  your anatomy, biomechanics and neuromechanics and bring them together into a competent clinical examination to know when the correction will lead to optimal gait and when it will drive suboptimal gait. Just because you see it and think it is bad, does not make it so.  

New to this cross over stuff ? Head over to the search box here on our blog and type in “cross over” or “cross over gait” and you will find dozens of articles and some great videos we have done to help you better grasp it. 

* you will also note that this runner is in an excessive lateral forefoot strike posturing.  This means that excessive and abrupt prontation will have to follow through the mid-forefoot in order to get the medial foot tripod down and engaged.  The question is however, is what you are seeing a product of the steep limb angle from the cross over, or does this runner have a forefoot varus (functional or anatomic, rigid or flexible)?  Are the peronei muscles weak, making pre-contact foot/ankle eversion less than optimal ? This is an important point, and your clinical examination will define that right away … . . if you know what these things are.  And if you don’t ? Well, you have found the right blog, one with a SEARCH box. Type in “forefoot varus”, if you want to open up the rabbit hole and climb down it … . . we dare ya ! :-)

A year ago we produced this  short video (link)  on how to bring back the EHB (extensor hallucis Brevis muscle). Well, it continues to do its magic on a regular basis. Here is a patient’s foot with clear demonstration of unassisted success of isolated engagement of the EHB while simultaneous release of the EHL (ext. Hallucis long us) while engaging the FHL (flexor hallucis long us).  This patient could not isolate any of the long or short hallux muscles on his own. “I can’t find it, my brain doesn’t know what it is supposed to do or how to do it ! (paraphrased)  But after just 24 hours consisting of a few sessions of the exercise here is the result in the photo above.  Success !  And here were his comments:  
 
 Doc, you were right - the brain is an amazingly plastic thing!  I’ll keep working on it, but happy to see such quick progress! 
 
 The client’s problem was some medial mid-rear foot pain from the resultant excessive increased pronation because of a forefoot varus.  Well, it is a bit more complicated than that to be precise. There was some true clinical ankle and rearfoot instability because of a lifetime of ankle sprains as well as some highly suspect lower syndesmosis hypermobility from probable distal anterior tib-femoral ligamentous attenuation/tears but the main point is that these were clinically manifesting themselves because of the apparent forefoot varus and the resultant pronatory foot mechanics to get the 1st metatarsal head (medial tripod) to the ground; a typical phenomenon .  Here is the kicker, he did  not have a fixed forefoot varus, it was a mirage, it was functional.  What he had was an inability to descend the first metatarsal (plantarflex the Metatarsal) / medial tripod of the foot.  He could not do this because he could not separate ankle dorsiflexion and hallux dorsiflexion.  There was essentially no hallux dorsiflexion at all because he could not descend the 1st MET (head).  So, we knew it was time to break out the nuclear EBH exercise in the video above !  Big problems require big guns ! 
 The rest is history. We fully expect to see a virtual disappearance of the “so called” forefoot varus (because it was never present in the first place).  
 
 “If you have never seen the beast, you will not recognize it when you see it.”-unknown

A year ago we produced this short video (link) on how to bring back the EHB (extensor hallucis Brevis muscle). Well, it continues to do its magic on a regular basis. Here is a patient’s foot with clear demonstration of unassisted success of isolated engagement of the EHB while simultaneous release of the EHL (ext. Hallucis long us) while engaging the FHL (flexor hallucis long us).  This patient could not isolate any of the long or short hallux muscles on his own. “I can’t find it, my brain doesn’t know what it is supposed to do or how to do it ! (paraphrased)  But after just 24 hours consisting of a few sessions of the exercise here is the result in the photo above.  Success !  And here were his comments: 

Doc, you were right - the brain is an amazingly plastic thing!

I’ll keep working on it, but happy to see such quick progress!

The client’s problem was some medial mid-rear foot pain from the resultant excessive increased pronation because of a forefoot varus.  Well, it is a bit more complicated than that to be precise. There was some true clinical ankle and rearfoot instability because of a lifetime of ankle sprains as well as some highly suspect lower syndesmosis hypermobility from probable distal anterior tib-femoral ligamentous attenuation/tears but the main point is that these were clinically manifesting themselves because of the apparent forefoot varus and the resultant pronatory foot mechanics to get the 1st metatarsal head (medial tripod) to the ground; a typical phenomenon .  Here is the kicker, he did  not have a fixed forefoot varus, it was a mirage, it was functional. What he had was an inability to descend the first metatarsal (plantarflex the Metatarsal) / medial tripod of the foot.  He could not do this because he could not separate ankle dorsiflexion and hallux dorsiflexion.  There was essentially no hallux dorsiflexion at all because he could not descend the 1st MET (head).  So, we knew it was time to break out the nuclear EBH exercise in the video above !  Big problems require big guns !

The rest is history. We fully expect to see a virtual disappearance of the “so called” forefoot varus (because it was never present in the first place). 

“If you have never seen the beast, you will not recognize it when you see it.”-unknown

When a stability shoe makes things worse.

Look at this video. This is a video of what was a midfoot-forefoot pronator who was fitted into a high stability motion control shoe. This appears to be a Brooks Adrenaline GTS shoe.

You can see that the shoe appears to help limit the pronation at the rear and mid foot but a keen eye will easily tell you that this person is pronating heavily through the forefoot.  This may in fact be a person with forefoot varus.

You need to know your shoe types, foot types and when to pair them up. This pairing actually blocked much of the rear and midfoot pronation but forced it all to occur through the forefoot at an abrupt rate. This abruptness increases the likelihood of metatarsal osseous stress responses and for anterior or posterior shin splints.

This person needs more ankle stability to protect from the degree of ankle valgus and they could also use more hip and knee stability to prevent the genu valgum loading (medial knee posturing) as well as the Cross Over deficits. A little bit of rehab, body awareness and some foot exercises will go a long way here. A more accommodative shoe could help, too. We are not sure of the foot type obviously, but if we have a rigid forefoot varus a medial MET  head post (a Rothbart-type) wedge could help this client immensely. 

There is much going on here, but the big point we wanted to hit home here is that even a high end motion control shoe cannot block all pronation, especially if it occurs in the forefoot. Many orthotics fair to address forefoot pronation as well, merely because the control of the device does not extend into the forefoot. Sure, some can be dampened by changes in the rear and midfoot, but this case should prove that sometimes it is not enough.  

If you want to learn more about proper matching of feet and shoes, our National Shoe Fit PRogram will take you a long way.

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

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

other web based Gait Guys lectures:

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

Shawn and Ivo

Podcast 38: Usain Bolt, Arm Swing, Ballasts, & Running "Stuff"

Our show notes should interest you today. We have another great podcast ready for you !

Link to our server:

 http://thegaitguys.libsyn.com/podcast-38-usain-bolt-arm-swing-ballasts-running-stuff

iTunes link:

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

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

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

other web based Gait Guys lectures:

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

Today’s show notes:

2. Running and walking gadget:
Mashable (@mashable)
9/10/13 4:53 AM
This Clip-On Device Lets You Read Your Tablet While You Runon.mash.to/1akqMaK
4. Arm Swing:
- The Ballast Theory 
5. Off the web: Children’s Shoes
6. Off the MEdical Journal:
7.  Clinical Case Questions from a Reader:
Hello there, I’ve been following your stuff for a while now after searching far and wide for solutions to issues I have with my feet/ankles … . .
Chris 
8. Topic: Bartold on heelstrike
9. From the Medical Journal:
Neuroscientist. 2004 Aug;10(4):347-61.
Regulation of arm and leg movement during human locomotion.

Zehr EPDuysens J.

Rehabilitation Neuroscience Laboratory, University of Victoria, BC, Canada. pzehr@uvic.ca

Abstract: Walking can be a very automated process, and it is likely that central pattern generators (CPGs) play a role in the coordination of the limbs. Recent evidence suggests that both the arms and legs are regulated by CPGs and that sensory feedback also regulates the CPG activity and assists in mediating interlimb coordination. Although the strength of coupling between the legs is stronger than that between the arms, arm and leg movements are similarly regulated by CPG activity and sensory feedback (e.g., reflex control) during locomotion

10. Off pubmed: 
J Am Podiatr Med Assoc. 2012 Sep-Oct;102(5):390-5.

Anatomical origin of forefoot varus malalignment.

Lufler RSHoagland TMNiu JGross KD.
Forefoot varus malalignment is clinically defined as a nonweightbearing inversion of the metatarsal heads relative to a vertical bisection of the calcaneus in subtalar joint neutral. Although often targeted for treatment with foot orthoses, the etiology of forefoot varus malalignment has been debated and may involve an unalterable bony torsion of the talus. There was no association between forefoot alignment and talar torsion (r = 0.18; 95% confidence interval, -0.11 to 0.44; P = .22).These findings may have implications for the treatment of forefoot varus since they suggest that the source of forefoot varus malalignment may be found in an alterable soft-tissue deformity rather than in an unalterable bony torsion of the talus.

Podcast 37: Anandamide & Body Work, 3D Printed Shoes and Case Studies

Our show notes should interest you today. We have another great podcast ready for you today !

Link to our server:

http://thegaitguys.libsyn.com/podcast-37-anandamide-body-work-3d-printed-shoes-and-case-studies

iTunes link:

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

Gait Guys online /download store:

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

other web based Gait Guys lectures:

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

Today’s show notes:

Neuroscience piece:

McPartland et al (2005) measured Anandamide (AEA) levels pre- and post, Myofascial Release, Muscle Energy Technique, High velocity manipulation all of which load fascia patients experienced analgesic/euphoric cannabimimetic effects, which correlated with an increase in serum AEA levels (more than double pre-treatment evels). 
Neither cannabimimetic effects, nor changes in AEA levels, occurred in control subjects.

McPartland, J et al 2005.. Jnl. American Osteopathic Association 105, 283–291 
http://leonchaitow.com/2008/01/30/bodywork-high
2. Vibrating shoes could be the future of navigation and wearable tech
http://www.wired.co.uk/magazine/archive/2013/09/start/vibrating-shoes-the-new-navigation-tool
3. Tim Ferriss (@tferriss)
9/2/13 9:25 PM
Malcolm Gladwell: “Man and Superman” The New Yorker buff.ly/174jruO Drugs, genetics, and the fallacy of a level playing field.
 
4.FB reader sent us a message:

Hi Guys: Not quite sure how I came across your podcasts but really enjoying them, even if I’m only slowly starting to understanding them. I was catching up on some old ones during my marathon training and the ones on evolution reminded me of some of my musing on the arch in the foot (well I guess correctly that should be the medial longitudinal arch). I though you might be able to give me the answers or point me in the right direction

Are we only species with this?
What is the advantage?
When and how does it develop and why isn’t it formed in utero?
Are flat feet then a genetic or developmental issue and why?
Thanks 
Alex
5. off the web:
The imprecise art of foot orthoses
6. off the web:
3D-Printed Shoes Mean You’ll Never Need to Buy Another Pair
http://mashable.com/2013/08/20/3d-printed-shoes/
7. Another TUMBLR reader asks question about:
Hi Gait Guys,

I am currently a third year podiatry student needing some biomechanics and orthotic-making training. I enjoy your youtube videos but was wondering if you offer or could recommend a dvd that I could purchase to further my education. The way the information is presented it in class is not as good as the way you do it! I am also interested in the biomechanics of shoes… I am having trouble finding information about how walking in a cushioned/plantarflexed sneaker effects function (Does is help us get to forefoot running or hinder us?). I enjoyed your blog on different curved lasts as well. How would I be able to apply the way the shoe is lasted to a patient? For example, if the patient is rigid and I want them to be wearing a shoe that is lasted like a slipper how do I guide them into buying a shoe constructed as such? Do I just tell them to go for a shoe made with a straight toe box? Is there such a thing as a toe box curved laterally? 

One last question- do you recommend a medial FF post for a patient that has a mobile RF varus that causes a FF supinatus? I was told a post like this would limit PF of the first ray and DF of the hallux which would limit toe off and cause other problems. 
Thank you. I appreciate any advice you may have. I am out of my element with biomechanics and really want to improve at it.

8.Another off tumblr: 
sign-life-away asked you:
Is forefoot walking bad for you? Everyone says I walk awkwardly, as if i have something up my bum. I have been trying to walk “naturally” (heel-toe) but I go back to forefoot strike. Does this contribute to why my legs have always been muscular?
This is a follow up to our last post on forefoot varus, available here.

Remember, ou are looking at a person with an uncompensated, rigid fore foot varus. This individual is not able to get the head of the 1st ray to the ground at all, and he has a Morton’s foot to boot (no pun intended). 
So, what do we see?

  • 1st of all, you will note his 2nd metatarsal is longer than his 1st. When he goes up on his toes, you see his foot invert and will see curling of the toes 3-5 in an attempt to stabilize the foot. 
  • You will also see his foot looks pretty flat. He has an arch (you can see it as he goes up onto his toes) and the “flatness” is actually due to the fore foot varus.
  • You will see a bunion forming bilaterally, due again to the uncompensated fore foot varus, and his inability to anchor the head of the 1st metatarsal. 
  • The posterior view shows relatively vertical calcaneii (no no rearfoot valgus), but you can really see the effects of the fore foot varus, with medial fall of the midfoot.
  • note the prominent “pump bumps” on the lateral calcaneus biaterally, from chronic rubbing on the shoes. 
The Gait Guys. Getting you closer to being a foot nerd with each post.
 
Lost? Having trouble with all these terms and nomenclature? Take our national shoe fit program, available by clicking here.

The Gait Guys. Uber foot geeks. Still bald and good looking. Separating the wheat from the chaff, with each and every post.

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What do we have here and what type of shoe would be appropriate?

You are looking at a person with a fore foot varus. This means that the fore foot (ie, plane of the metatarsal heads) is inverted with respect to the rear foot (ie, the calcaneus withe the subtalar joint in neutral). Functionally translated, this means that they will have difficulties stabilizing the medial tripod (1st MET head) to the ground making the forefoot and arch unstable and likely rendering the rate and degree of pronation increased.

Having trouble with terminology? check out this post on FF varus.

The incidence of this condition is 8% of 116 female subjects (McPoil et al, 1988) and 86% of 120 male and female subjects (Garbalosa et al, 1994), so it happens more in males.

Fore foot varus occurs in 3 flavors:
  • compensated
  • uncompensated
  • partially compensated
What is meant by compensated, is that the individual is able to get the head of the 1st ray to the ground completely (compensated), partially, or, when not at all, uncompensated.
What this means from a gait perspective ( for partially and uncompensated conditions) is that the person will pronate through the fore foot to get the head of the 1st ray down and make the medial tripod of the foot (ie, they pronate through the subtalar joint to allow the 1st metatarsal to contact the ground). This causes the time from mid-stance to terminal stance to lengthen and will inhibit resupination of the foot. We will have an upcoming additional post on this soon and will put a link here when we do.
Today we are looking at a rigid, uncompensated forefoot varus, most likely from insufficient talar head derotation during fetal development and subsequent post natal development. They will not get to an effective foot tripod. They will collapse the whole foot medially. These people look like severely flat-footed hyperpronators.

So, what do you do and what type of shoe is appropriate? Here’s what we did:
  • try and get the 1st ray to descend as much as possible with exercises for the extensor hallucis brevis and short flexors of the toes (see our videos on youtube)
  • create more motion in the foot with maniipuulation, massage mobilization to optimize what is available
  • strengthen the intrinsic muscles of the feet (particularly the interossei
  • increase strength of the gluteus maximus and posterio fibers of the gluteus medius to slow internal rotation of the leg during initial contact to midstance
  • put him in a flexible shoe for the 1st part of the day, to exercise the feet and a more supportive, medially posted (ideally fore foot posted) shoe for the latter part of the day as the foot fatigues
  • monitor his progress at 3-6 month intervals
  • a rigid orthotic will likely not help this client and they will find it terribly uncomfortable because this is a RIGID deformity for the most part (the foot will not accommodate well to a corrective orthotic. Besides, the correction really has to be made at the forefoot anyways. We will talk about medial forefoot postings again at a later date.)
Lost? Having trouble with all these terms and nomenclature? Take our national shoe fit program, available by clicking here.

The Gait Guys. Uber foot geeks. Still bald and good looking. Separating the wheat from the chaff, with each and every post.

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Subtle clues often tell the story. A case 

A young athlete that wants to be faster (he is a 4:17 miler).

In the 1st shot we see he has an anatomically short R tibia (and the gait to match it). You will note the right tibial plateau is lower than the left. The 2nd shot backs this up; look at the malleoli.

The next shot shows a FABER test f the L hip. Compare the range of motion with the right one. Hmmm.  Limited external rotation and abduction on the right.  It should be noted he had normal and relatively symmetrical internal rotation of both hips.

Now come the feet. 1st the left. A relatively neutral foot. Next the right. What’s different? Note how much more pronounced the right 1st ray (ie 1st metatarsal phalangeal joint).

Think about his short side. Most likely, he will be trying to lengthen it, right? How would he accomplish that? By supinating the foot (making it more rigid) and attempting to lengthen that leg, by anterior rotation of the pelvis. If you anteriorly rotate the pelvis (ie the innominate rotates forward, bringing the ASIS forward), what happens to external rotation of the hip? Stand up, edtend your hip on your pelvis and find out. It limits it.

How else might he try to lengthen that leg? If he supinates the foot (ie planytarflexion, adducion and inversion), the foot will be more inverted. He will be trying to get that medial tripod down to the ground. How might he accomplish that? By plantarflexing the 1st ray!

So how can we make him faster?

  • Place sole lift under r foot
  • Correct pelvic pathomechanics with manipulation
  • Support coorection with appropriate exercise (he had weak R lower external oblique’s)
  • Foot mobilization
  • R Foot intrinsic exercises to promote rasing of the 1st ray (extensor hallicus longus  and flexor hallicus brevis exercises)  and lowering of the lesser metatarsal heads (extensor digitorum brevis exercises ).

The answers are often in the details. Be detail oriented. That’s one of the things that makes us foot geeks.

Ivo and Shawn