Support for a midfoot strike?
“Running with a midfoot strike pattern resulted in a significant increase in gastrocnemius lateralis pre-activation (208 ± 97.4 %, P < 0.05) and in a significant decrease in tibialis anterior EMG activity (56.2…

Support for a midfoot strike?

Running with a midfoot strike pattern resulted in a significant increase in gastrocnemius lateralis pre-activation (208 ± 97.4 %, P < 0.05) and in a significant decrease in tibialis anterior EMG activity (56.2 ± 15.5 %, P < 0.05) averaged over the entire stride cycle. The acute attenuation of foot-ground impact seems to be mostly related to the use of a midfoot strike pattern and to a higher pre-activation of the gastrocnemius lateralis. ”

Do these results surprise you? They didn’t really surprise us.

The lateral head of the gastroc is a midstance to preswing stabilizer and works synergistic with the medial head, with the medial head firing earlier. Sutherland talks about these muscles not being propulsive in nature, but rather maintainers of forward progression, step length and gait symmetry. Thinking this through in a closed chain (foot up) fashion, this would counter the inversion moment created by the medial gastroc for supination in the second half of contact phase. If the foot is already partially supinated (as we believe it would be in a midfoot strike), it would have to pre activate.

A decrease in tibialis anterior activity? Sure. If the foot is striking more parallel to the ground, the anterior compartment (including the tibialis anterior, extensor hallucis longus, and extensor digitorum longus) would not have to eccentrically contract to decelerate the lowering of the foot to the ground.

Better? Maybe, maybe not. We are seeing more and more literature about foot strike (if you missed our last few posts, click here, here, here and here), We still maintain that you need a competent lower kinetic chain, including the foot and an intact nervous system to drive the boat.

We remain, handsome, bald and nerdy…Ivo and Shawn

                                                                                                                                

Eur J Appl Physiol. 2012 Aug 9. [Epub ahead of print]

Impact reduction during running: efficiency of simple acute interventions in recreational runners.

Source

University of Lyon, 42023, Saint-Etienne, France.

Abstract

Running-related stress fractures have been associated with the overall impact intensity, which has recently been described through the loading rate (LR). Our purpose was to evaluate the effects of four acute interventions with specific focus on LR: wearing racing shoes (RACE), increasing step frequency by 10 % (FREQ), adopting a midfoot strike pattern (MIDFOOT) and combining these three interventions (COMBI). Nine rearfoot-strike subjects performed five 5-min trials during which running kinetics, kinematics and spring-mass behavior were measured for ten consecutive steps on an instrumented treadmill. Electromyographic activity of gastrocnemius lateralis, tibialis anterior, biceps femoris and vastus lateralis muscles was quantified over different phases of the stride cycle. LR was significantly and similarly reduced in MIDFOOT (37.4 ± 7.20 BW s(-1), -56.9 ± 50.0 %) and COMBI (36.8 ± 7.15 BW s(-1), -55.6 ± 29.2 %) conditions compared to NORM (56.3 ± 11.5 BW s(-1), both P < 0.001). RACE (51.1 ± 9.81 BW s(-1)) and FREQ (52.7 ± 11.0 BW s(-1)) conditions had no significant effects on LR. Running with a midfoot strike pattern resulted in a significant increase in gastrocnemius lateralis pre-activation (208 ± 97.4 %, P < 0.05) and in a significant decrease in tibialis anterior EMG activity (56.2 ± 15.5 %, P < 0.05) averaged over the entire stride cycle. The acute attenuation of foot-ground impact seems to be mostly related to the use of a midfoot strike pattern and to a higher pre-activation of the gastrocnemius lateralis. Further studies are needed to test these results in prolonged running exercises and in the long term.

PMID:22875194 [PubMed - as supplied by publisher]


All material copyright 2013 The Gait Guys/The Homunculus Group, yada, yada, yada…

Gait Guys, can I wear my racing flats during regular weekly base runs ?

Perhaps the better question is “should you wear your racing flats for regular base building runs ?"  Most injuries are based on a volume of impact miles across anatomy structures that are not appropriately protected or which have been encouraged into biomechanically challenged positions because of surrounding weakness or functional asymmetry.

In previous blog posts we have talked about the theory that more EVA foam is not always better and supported these ideas with research.  However, the pendulum can swing to the opposite as well. It is also plausible that a tipping point of less foam also increases risk because of a lack of shock attenuation.  The results of the study below demonstrated significant differences in peak pressure, maximum force, and contact area between the two shoe conditions of racing flat and regular training shoes (see study for specifics). There was a significantly higher maximum force measured in the lateral midfoot in the racing flats while an increased maximum force was observed beneath the rearfoot in the training shoe, 

What the study did not go into was the foot type and the running form from what we could tell. Heck, it is even possible that the small "n” of the study could have included a bolus of cross over runners with forefoot varus for all we know. the study did not delve that deep. We have all learned that often it is not what you do but how you do it and additionally, although not entirely pertinent here, that what we see is often not the problem (translation: just because the peak pressures measured high in an area does not necessarily mean that the adjacent anatomical structure to the peak pressure will suffer the impact and trauma of said pressures. This is a dynamic load sharing organism, where things break down is rarely where the problem exists)

Bottom line from our standpoint, and this does not hold true for everyone but it is a fairly safe statement, if your foot type is not pristine and your running form could stand some perfecting then perhaps running flats for anything than race day is not the most sane and cerebral decision.  This may be especially true if you are milking some subtle injuries or asymmetries that speak to you from time to time on a run.  But to each his own.  Human’s are inherently risk takers and subject to cognitive dissonance, especially when things are going well. And who knows, runners may fall even deeper into this profile for all we know.

Here is the study for your perusal. 

If you want to get better at this game of assessment, shoe fitting and foot type matching you might want to consider our National Shoe Fit Program.  Email us at  thegaitguys@gmail.com if you want us to send you some information on our program.

Shawn and Ivo, The Gait Guys

Differences in plantar loading between training shoes and racing flats at a self-selected running speed.

 Wiegerinck JI et al.  Gait Posture. 2009 Apr;29(3):514-9. Epub 2009 Jan 14.

Summarized Abstract:

The purpose of this study was to examine the difference in plantar loading between two different running shoe types. We hypothesized that a higher maximum force, peak pressure, and contact area would exist beneath the entire foot while running in a racing flat when compared to a training shoe. Peak pressure, maximum force, and contact area beneath eight different anatomical regions of the foot as well as beneath the total foot were obtained. The results of this study demonstrated a significant difference between training shoes and racing flats in terms of peak pressure, maximum force, and contact area. The significant differences measured between the two shoes can be of importance when examining the influence of shoe type on the occurrence of stress fractures in runners.

Looks like Newbies are heel strikers 
&ldquo;Nearly all novice runners utilize a rearfoot strike when taking up running in a conventional running shoe. Hereby, the footstrike patterns among novice runners deviate from footstrike patterns among elite…

Looks like Newbies are heel strikers

“Nearly all novice runners utilize a rearfoot strike when taking up running in a conventional running shoe. Hereby, the footstrike patterns among novice runners deviate from footstrike patterns among elite and sub-elite runners.”


please take some time to explore the links we put in, as they are germane to the post


The question begs, “Why?”

  • do they believe running is merely an extension of walking, and just “speed up” the process?
  • are they afraid of going too fast and are using the heel strike to “brake”?
  • do they learn to strike differently with more experience? at least one paper eludes to “yes”
  • is it “more comfortable” as this paper says it may be?
  • If there is a rear foot strike, the foot is poised to be able to pronate to a greater degree. This theoretically means it (ie, the foot) can absorb more shock through this mechanism, although this seemingly contradicts the Lieberman study

This paper certainly had a nice cohort size (> 900 runners) so we can state, at least for this group, that this is not by chance.  When there is a fore foot strike, the foot is more supinated and makes a seemingly “rigid lever”, does this mean there is less shock (perceived or actual) with this foot posture?

Lots of questions. This is only 1 part of the puzzle.

The Gait Guys. Sifting through the literature and giving you the beef

            

Gait Posture. 2012 Dec 29. pii: S0966-6362(12)00448-1. doi: 10.1016/j.gaitpost.2012.11.022. [Epub ahead of print]

Footstrike patterns among novice runners wearing a conventional, neutral running shoe.

Bertelsen ML, Jensen JF, Nielsen MH, Nielsen RO, Rasmussen S.

Aarhus University Hospital, Aalborg Hospital, Orthopaedic Surgery Research Unit, Science and Innovation Center, Aalborg DK-9000, Denmark. Electronic address: miclejber@gmail.com.

Abstract

INTRODUCTION:

It has been suggested that striking on the midfoot or forefoot, rather than the rearfoot, may lessen injury risk in the feet and lower limb. In previous studies, a disparity in distribution in footstrike patterns was found among elite-, sub-elite, and recreational runners.

PURPOSE:

The purpose of this study was to investigate the footstrike patterns among novice runners.

METHODS:

All runners were equipped with the same conventional running shoe. Participants were video filmed at 300 frames per second and the footstrike patterns were evaluated by two observers. The footstrike was classified as rearfoot, midfoot, forefoot, or asymmetrical.

RESULTS:

A total of 903 persons were evaluated. The percentages of rearfoot-, midfoot-, forefoot-, and asymmetrical footstrike among men were 96.9%, 0.4%, 0.9%, and 1.8%, respectively. Among women the percentages were 99.3%, 0%, 0%, and 0.7%, respectively.

CONCLUSION:

Nearly all novice runners utilize a rearfoot strike when taking up running in a conventional running shoe. Hereby, the footstrike patterns among novice runners deviate from footstrike patterns among elite and sub-elite runners.

Copyright © 2012 Elsevier B.V. All rights reserved.


PMID: 23280125 [PubMed - as supplied by publisher]



all material copyright 2013 The Gait Guys/The Homunculus group. Please don’t lift our stuff without asking and giving credit.

A return to "the solitary externally rotated foot"

Dear Gait Guys:

I compete at a high level in a variety of sports, but over the past five years I have developed tremendous discomfort and occasional pain.  I have talked to orthopedic surgeons and physical therapists with no results.  I had MRIs done on my hip, shoulder and knee (my problem areas) but they came back clean.  Finally I saw your article on the “solitary externally rotated foot”.  My symptoms of the outward turned foot, weak glutes, uncomfortable patellar tracking and limited hip rotation.  Also, my shoulder seems to be externally rotated as well which causes pain and inhibits my pec major from firing.  You guys are the only ones who have come close to figuring out my problems and are the only refuge from my frustration.  How can I fix this?  Are their some good exersizes and why have no physical therapists heard of the “kickstand effect”?  

Thank you so much,
(name withheld, NW)
_____
Dear NW
We loosely used the name “kickstand Effect” to describe in part what the foot is acting as. By turning out the foot into the frontal plane you are engaging more of the frontal plane for stability, stability which you likely do not have in the frontal plane by the primary pattern stabilizer(s) and or synergists.
Without more clinical hands on exam we are at a loss to help you, remember a clean objective examination followed by a solid screen of movement patterns is always paramount, something we just cannot obtain over the internet.  We would love to give theories and exercises, but then we would just be shooting from the hip and and in a case like this more compensations (if we give the wrong recommendations) is not what you need at your level and level of frustration.  But, we wanted to share this kind readers case and attach the original article they were referring to. After all, it has been more than a year since we wrote it.
Here is the link:  “THE SOLITARY EXTERNALLY ROTATED FOOT”
SHAWN AND IVO
the gait guys
Functional Ankle Instability and the Peroneals  

Lots of links available here with today&rsquo;s blog post. please make sure to take your time and check out each one (underlined below)  
As you remember, the peroneii (3 heads) are on the outside of…

Functional Ankle Instability and the Peroneals 


Lots of links available here with today’s blog post. please make sure to take your time and check out each one (underlined below) 

As you remember, the peroneii (3 heads) are on the outside of the lower leg (in a nice, easy to remember order of longus, brevis and tertius, from top to bottom) and help to stabilize the lateral ankle. The peroneus brevis and tertius dorsiflex and evert the foot while the peroneus longus plantarflexes and everts the foot. We discuss the peroneii more in depth here in this post. It then is probably no surprise to you that people with ankle issues, probably have some degree of peroneal dysfunction. Over the years the literature has supported notable peroneal dysfunction following even a single inversion sprain event. 

Functional ankle instability (FAI) is defined as “ the subjective feeling of ankle instability or recurrent, symptomatic ankle sprains (or both) due to proprioceptive and neuromuscular deficits." 

Arthrogenic muscle inhibition (AMI) is a neurological phenomenon where the muscles crossing a joint become "inhibited”, sometimes due to effusion (swelling) of the joint (as seen here) and that may or may not be the case with the ankle (see here), or it could be due to nociceptive input altering spindle output or possibly higher centers causing the decreased muscle activity. 

This paper (see abstract below) merely exemplifies both the peroneals and FAI as well as AMI.

Take home message?

Keep the peroneals strong with lots of balance work!

The Gait Guys: bringing you the meat, without the filler!                                                                         

Am J Sports Med. 2009 May;37(5):982-8. doi: 10.1177/0363546508330147. Epub 2009 Mar 6.

Peroneal activation deficits in persons with functional ankle instability.

Source

School of Kinesiology, University of Michigan, 401 Washtenaw Avenue, Ann Arbor, MI 48109, USA. riannp@umich.edu

Abstract

BACKGROUND:

Functional ankle instability (FAI) may be prevalent in as many as 40% of patients after acute lateral ankle sprain. Altered afference resulting from damaged mechanoreceptors after an ankle sprain may lead to reflex inhibition of surrounding joint musculature. This activation deficit, referred to as arthrogenic muscle inhibition (AMI), may be the underlying cause of FAI. Incomplete activation could prevent adequate control of the ankle joint, leading to repeated episodes of instability.

HYPOTHESIS:

Arthrogenic muscle inhibition is present in the peroneal musculature of functionally unstable ankles and is related to dynamic peroneal muscle activity.

STUDY DESIGN:

Cross-sectional study; Level of evidence, 3.

METHODS:

Twenty-one (18 female, 3 male) patients with unilateral FAI and 21 (18 female, 3 male) uninjured, matched controls participated in this study. Peroneal maximum H-reflexes and M-waves were recorded bilaterally to establish the presence or absence of AMI, while electromyography (EMG) recorded as patients underwent a sudden ankle inversion perturbation during walking was used to quantify dynamic activation. The H:M ratio and average EMG amplitudes were calculated and used in data analyses. Two-way analyses of variance were used to compare limbs and groups. A regression analysis was conducted to examine the association between the H:M ratio and the EMG amplitudes.

RESULTS:

The FAI patients had larger peroneal H:M ratios in their nonpathological ankle (0.399 +/- 0.185) than in their pathological ankle (0.323 +/- 0.161) (P = .036), while no differences were noted between the ankles of the controls (0.442 +/- 0.176 and 0.425 +/- 0.180). The FAI patients also exhibited lower EMG after inversion perturbation in their pathological ankle (1.7 +/- 1.3) than in their uninjured ankle (EMG, 3.3 +/- 3.1) (P < .001), while no differences between legs were noted for controls (P > .05). No significant relationship was found between the peroneal H:M ratio and peroneal EMG (P > .05).

CONCLUSION:

Arthrogenic muscle inhibition is present in the peroneal musculature of persons with FAI but is not related to dynamic muscle activation as measured by peroneal EMG amplitude. Reversing AMI may not assist in protecting the ankle from further episodes of instability; however dynamic muscle activation (as measured by peroneal EMG amplitude) should be restored to maximize ankle stabilization. Dynamic peroneal activity is impaired in functionally unstable ankles, which may contribute to recurrent joint instability and may leave the ankle vulnerable to injurious loads.

all material (except for the study); copyright 2013 The Gait Guys/ The Homunculus Group. All rights reserved. Please ask before you lift our stuff. If you are nice and give us credit, we will probably let you use it!

New Study Finds Group of Heel Striking Barefoot Kenyan Runners.
Not all that is barefoot is necessarily forefoot&hellip;
You may have seen our tweet yesterday and have read this article. Or maybe, because you are a foot geek, you have seen it alread…

New Study Finds Group of Heel Striking Barefoot Kenyan Runners.

Not all that is barefoot is necessarily forefoot…

You may have seen our tweet yesterday and have read this article. Or maybe, because you are a foot geek, you have seen it already.

Here’s the summary: “Jan. 9, 2013 — A recently published paper by two George Washington University researchers shows that the running foot strike patterns vary among habitually barefoot people in Kenya due to speed and other factors such as running habits and the hardness of the ground. These results are counter to the belief that barefoot people prefer one specific style of running.”

The study reported a 72 percent rearfoot landing when running barefoot at endurance pace speeds supporting the notion that speed affects landing choice (faster speeds transitioned  the runners into more midfoot / forefoot landing).  Lieberman’s Harvard study which brought much of the forefoot strike principle to the western world was often based off of sub 5 mile paced runs.

It raises the question “ If barefoot IS better, and forefoot impact IS BETTER, then, what gives?”

We think the better response is:

  • there are many variables (genetics, surface, speed, etc) that can influence foot strike patterns and this paper exemplifies that.
  • Fore foot striking in runners does lessen impact forces.
  • Forefoot striking does appear to accentuate any forefoot abnormality (ie: varus/valgus) that may be present (something we will continue to say until someone proves it otherwise).
  • forefoot striking loads the posterior compartment of the lower leg (tricep surae (gastroc soleus complex)) to a greater degree

We like a mid foot strike, not because it is the middle road, but because it supports the notion in distance running that the entire foot tripod (which is more stable) engages the ground reducing solitary forefoot and rearfoot loading issues which each have their risks and challenges and allows for a more stable contact point for the body to negotiate over.  We have pounded sand on forefoot types, and the inherent risks of forefoot strike running with each of them, from our inception.  But, when it comes to midfoot strike there doesn’t appear to be much, if any literature out there to support our opinion.  Maybe now that the forefoot and rearfoot studies are out there maybe someone will find a tribe of midfoot strikers to support our rants.

We think the key is not necessarily strike position, but rather where the foot is hitting the ground relative to the body AND MORE IMPORTANTLY, having a competent foot and lower kinetic chain and core, along with the body’s ABILITY to absorb or attenuate those forces, no matter where the foot is striking the ground.

This is no doubt the 1st in a series of papers looking at this. It will be interesting to see where it goes from here.

Ivo and Shawn…  The Gait Guys

here is the link: http://www.sciencedaily.com/releases/2013/01/130109185856.htm

all material copyright 2013 The Homunculus Group/ The Gait Guys. Please ask to use our stuff and reference it appropriately. We know a guy named BamBam who helps people play nice.

Gait Guys, What is the truth when it comes time to buying/rotating new shoes ?

A few moons ago an awesome Facebook reader asked us about changing shoes and the validity of the “press test”.  Here was Eve’s link to the press test and here is what it said:
 Do the Press Test

“To determine if the midsoles of your shoes are compressed and are no longer providing cushioning, do the press test. Using your thumb, push on the outsole upward into the midsole. With new shoes, it should be easy to see the midsole compress into lines or wrinkles. As the shoe wears down, the midsole compresses less with the same amount of pressure. When the midsole shows heavy compression lines and the press test reveals a minimal amount of compression, there is little or no cushioning left.”

There is a valid point to this test, but it might be considered too rudimentary by many purists.  But most purists rarely can offer us a better solution.  Here is the issue, EVA foam has a lifespan in terms of maintaining its initial shock absorption. EVA foam cells compress and deform over time, most foam in this world does whether it is your Tempurpedic mattress, the foam base for your rugs or your car seat. And with areas of greater wear and compression the foam accelerates its deformation. This is why certain areas of your car seats, your rugs and your bed get softer.  The same thing goes with your shoes. But they really do not get softer, the areas get compressed and the foam changes its density and its integrity. It no longer performs.  Resistance, compressibility and resilience changes.  This is the problem with shoe foam as well, no matter what foam a company is using.  However, the bigger problem if you really think about it is that the foot type you have and the biomechanics (good or bad) that you drive your foam into will be the direction future foot loadings deviate into.  Can this be good ? Rarely. Can this be bad ? Usually.  EVA simply has a given number of cycles, and that number is variable with many factors in place such as weight, running form, foot strike, foot type, weathering of the foam, wet foam, dry foam, outer sole glue, foot bed components and attachment, number of miles.  So, degrading shoe foam is a fact of life for a walker or runner. 
The “press test” gives the user some idea of how much the foam is compressed and how much resilience it has left. But it is a test limited very much by the subjective assessment.  We wouldn’t hold a torch to the test and make it a solitary assessment factor, in fact we rarely do it ourselves. But every little test and assessment has some perks and information that can be gleaned from it.
For the record, we like to play it cautious because injuries cost money and time to a runner. So we error on the side of caution always and go for lower numbers for the life span of shoes.  Each shoe is different and we will  not leave you with actual numbers here because the algorithm gets a bit large and convoluted but the bottom line is that cheaper shoes usually use cheaper materials and more expensive shoes usually use better materials (yes, this does not always line up as truth, we know this).  But shoes like Newtons and Altras from our experience seem to survive the trials of running a bit better (at least in our athletes) and so we allow more miles in them.  But for those looking for some harder numbers here are our loose rules:
400-500 miles per pair of shoes.  At 200 miles begin a second pair of shoes and start alternating the shoes every run (old shoe one day, next day use the new shoe).  This will reduce the successive days in a shoe in which the foam is driving deeper and deeper into deformity and thus you are only a day away from a reprieve from the deforming shoe. This will reduce injury risk.  This will also give you a dry shoe on a run the day after a shoe got soaked or caked with mud.  Water and mud add shoe weight and change biomechanics. Once the older shoe his the end lifespan mark you have the second shoe at 200-250 and you are ready for a new shoe. So you are never in a shoe until its death, when it is completely deformed and driving pathomechanics and possible injury only to the very next day step into a new shoe with entirely different (albeit neutral and unbiased) mechanics in the foam.  Injuries occur much of the time with change. Be smarter with your shoe rotation and reduce change.
VITAL NOTE:
Running and walking use different biomechanics and loading styles. Walking has heel strike as a norm, running for the most part shouldn’t include heavy or any heel strike depending on the athlete and who’s “pulpit of running form” that athlete chooses to pray at the foot of. Like religion, there is no one right way …  we each need to find what is best for us. And thus, since running and walking biomechanics are so different you should keep your running shoes for running and have another pair for walking and your other workouts.  Remember though, running shoes are build mostly for sagittal (forward) movement and not for lateral sports. This is why you should never, never ever, use your running shoes for tennis, racquet ball, basketball or many forms of cross fit.  Get a court shoe that is build for lateral movement. Not only will the shoe last longer but it is built on a platform that is more suited for such activity.

Shawn and Ivo

The Gait Guys…….

tumblr_mg6a1wNO4i1qhko2so1_1280.jpg
tumblr_mg6a1wNO4i1qhko2so2_400.jpg

A little neuro, anyone?

Welcome to Monday, and yes, it is a NEURO day. In fact, if you got up this morning, you too are having a NEURO day. Dr Allen thinks it’s all about the ORTHOPEDICS, but without NEURO, there would not be any orthopedics : )

A dialogue from one of our avid readers, Dr. Ryan.

Dr. Ryan: Hey Ivo,

I just read this article on Mercola’s site which is an interview with Dr. Craig Buhler who does muscle activation techniques.  Can you check this for accuracy?  This must be a mistake b/c I always thought spindle activation will facilitate the muscle to contract.  Also, I always wondered why the O/I attachment points are tender in muscles that are inhibited.  Does his description sound right to you.  If not, do you have a better explanation?

“Your muscle system and nervous system relate to each other from within tiny muscle fibers called spindle cells, which monitor stretch. If your muscle is overloaded too rapidly, the spindle cells will temporarily inhibit the muscle. The next time you contract the muscle, it will fire again. Similarly, cells within your tendons called Golgi tendon organs also measure and monitor stretch. If your tendon is stretched too rapidly or exceeds its integrity, the Golgi tendon organs will temporarily inhibit the muscle. But the next time the muscle fires, it will again fire appropriately.

"But there’s a fail-safe system," Dr. Buhler explains. "It’s where the tendon attaches into the periosteum of the bone and the little fibers there are called Sharpey’s fibers. Those fibers are loaded with little receptors that monitor tension. And if the integrity of those fibers are exceeded, they inhibit the muscle, just like a circuit breaker would inhibit an electrical circuit.

Once that happens, the muscle will still fire under passive range of motion. But if you load the muscle, it gives way. If you continue to load the muscle, your body creates pain at the attachment points to protect you. What the central nervous system does at that point is compute an adaptive strategy by throwing stress into the muscle next to it. Other tissues begin to take on more of the load for the muscle that’s been injured.”

Here is a link to the entire article if you want to check it out:

http://fitness.mercola.com/sites/fitness/archive/2013/01/04/advanced-muscle-integration-technique.aspx?e_cid=20130104_DNL_art_1"

Dr Ivo: Thanks Dr. Ryan.

Spindles monitor length and GTO’s monitor tension. My understanding is spindles, when activated, stimulate the alpha motor neuron(at the cord) and cause contraction of that muscle or motor unit. GTO’s, when activated, cause inhibition of the muscle they are associated with. I am not aware of them being inhibitory, only GTO’s. They are believed to be GABAnergic synapses. The impulse (at least in cats) can be smaller or inhibited if the muscle is held in contraction for an extended period of time (see attached)

Perhaps he is talking about spindle dysfunction, where the intrafusal portion of the spindle (which is innervated by a gamma motor neuron) is either excited or inhibited. The gamma’s are more of a slave to the interneuronal pool (in the cord), which would be the sum total of all excitatory and inhibitory input to that area (ie the central integrated state). This not only reflects local receptor input but also cortical information descending (from areas 4s and 6 in the precentral gyrus) AND descending information from the caudal reticular formation.

Based on what you sent, I do not agree with the 1st 2 sentences. I was not aware about increased receptor density of Sharpeys fibers. I did a quick search and found this: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2100202/  , which eludes to it and here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3098959/. I will have to dive in more when I have time.

Not sure why O/I attachments are tender in inhibited muscles. I find them tender in most folks. Maybe because inhibited muscles ave altered receptor function and that preloads the nociceptive afferent pathway or at least that neuronal pool? Are they closer to threshold for some reason? Not sure. LMK what you find.

Thanks for getting me jazzed about sharpeys fibers!

for those of you who need to know YES, there will be a forthcoming Sharpeys fibers article

Dr. Ryan: That’s what I thought.  Thanks for looking into it and I will check out those links.  You have jazzed me plenty of times over the years.  Glad I could jazz you up for a change.  Have a great weekend.


Yes, Dr Ivo is definitely an uber neuro geek, especially when he spends time on the weekend talking about spindles!



all material copyright 2013 The Homunculus Group/ The Gait Guys. All rights reserved. Please as before you lift our stuff.

Previously unreleased Video Available for download

&ldquo;Performance Theories: Dialogues on Training Concepts&rdquo;
How about some one on one with Shawn and Ivo? Hear our thoughts on:


• What is the definition of the core and what does it entail…

Previously unreleased Video Available for download


“Performance Theories: Dialogues on Training Concepts”

How about some one on one with Shawn and Ivo? Hear our thoughts on:

• What is the definition of the core and what does it entail ?

• Physiologic overflow of muscles with respect to joint motion

• Isotonic Exercise concepts

• Physiologic characteristics of muscle types

• Strength Training: Neural Adaptation

• Motor Pattern Muscle Compensation Concepts

• Exercise Prescription Concepts

• Hip Extension Motor Pattern: A discussion on compensations

• Neurologic Reciprocal Inhibition: Principles of joint movement and stability

• The Concept of Tight and Short Muscles: They are different

• Stretching: Good or Bad?

We tackle the tough questions and provide real world answers.  An hour packed with hours worth of information! Download your copy here from Payloadz.

all material copyright 2009 The Homunculus Group/ The Gait Guys. All rights reserved.

acupuncture and muscle strength

“The present study shows that a single acupuncture treatment was efficacious for improving isometric quadriceps strength in recreational athletes. These results might have implications not only for athletic performance enhancement, but also for rehabilitation programs aimed at restoring neuromuscular function."  



Wow. What a statement! If you read the abstract, you will also read this ”The difference in the mean change in MIVF from baseline between acupuncture (46.6 N) and sham laser acupuncture (19.6 N) was statistically significant (p < 0.05), but no significant difference was found between acupuncture (46.6 N) and sham acupuncture (28.8 N)“  


So what was "sham acupuncture”? Simply put, acupuncture to non acupuncture meridian points. In other words, they put needles in muscles, just not on established meridians. Hmmm…Sounds alot like a form of dry needling. When you place a needle in a muscle, there is a good chance you will stimulate (or change function) of a muscle spindle or golgi tendon organ (length and tension receptors we have talked about before. see here, here, here, here, and here. guess we wrote about them a bit, eh?). Sham acupuncture still showed a positive result.                                                                  
                                                                                                                             
The bottom line? Needling the muscle changes how it contracts. It can be a useful tool for improving performance and rehabilitation.                                                                                                                                                                    
The Gait Guys. Geeks to the core. Bringing you the information to help you make better decisions with every post.  



September 2010, Volume 110, Issue 2, pp 353-358

Immediate effects of acupuncture on strength performance: a randomized, controlled crossover trial

Abstract

The present study investigated the immediate efficacy of acupuncture compared to sham acupuncture and placebo laser acupuncture on strength performance. A total of 33 recreational athletes (25.2 ± 2.8 years; 13 women) were randomized to receive acupuncture, sham acupuncture (needling at non-acupuncture points) and placebo laser acupuncture (deactivated laser device) in a double-blind crossover fashion with 1 week between trials. Assessment included bipedal drop jumps for maximum rebound height and quadriceps maximum isometric voluntary force (MIVF). Furthermore, surface electromyography (EMG) was used to measure the EMG activity of the rectus femoris muscle during a 30-s sustained MIVF of the knee extensors. Mean power frequency (MPF) analysis was applied to characterize muscular endurance. Measurements were performed at baseline and immediately after treatment by a blinded investigator. Repeated measures ANOVA and post hoc paired-sample t test with Bonferroni–Holm correction were used for statistical analysis. The difference in the mean change in MIVF from baseline between acupuncture (46.6 N) and sham laser acupuncture (19.6 N) was statistically significant (p < 0.05), but no significant difference was found between acupuncture (46.6 N) and sham acupuncture (28.8 N). ANOVA did not show statistically significant treatment effects for drop jump height or MPF. The present study shows that a single acupuncture treatment was efficacious for improving isometric quadriceps strength in recreational athletes. These results might have implications not only for athletic performance enhancement, but also for rehabilitation programs aimed at restoring neuromuscular function.

http://link.springer.com/article/10.1007%2Fs00421-010-1510-y

all material copyright 2013 The Gait Guys/ The Homunculus Group. All rights reserved.

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High Heels and …..Orthotics?

What better way to end the year than to talk about something that some of you have worn last evening. Not only clean underwear, but also high heels!

You have heard all about high heels here on the blog (if not, click here). Now here is some info that may be surprising! This study found that increased heel height caused increased plantar pressures (no surprises) BUT the use of an orthotic or arch pad, attenuated impact forces. IOHO not a reason to wear heels (though we DO like the way they look : )) but if you need to wear them (really? you need to wear them?), then maybe consider an insert to make it more bearable.

Ivo and Shawn                                              

                           

Appl Ergon. 2005 May;36(3):355-62.

Effects of shoe inserts and heel height on foot pressure, impact force, and perceived comfort during walking.

Source

Department of Industrial Management, National Taiwan University of Science and Technology, No. 43, Kee-Lung Road, Sec IV, Taipei, Taiwan, 106 ROC. yhlee@im.ntust.edu.tw

Abstract

Studying the impact of high-heeled shoes on kinetic changes and perceived discomfort provides a basis to advance the design and minimize the adverse effects on the human musculoskeletal system. Previous studies demonstrated the effects of inserts on kinetics and perceived comfort in flat or running shoes. No study attempted to investigate the effectiveness of inserts in high heel shoes. The purpose of this study was to determine whether increasing heel height and the use of shoe inserts change foot pressure distribution, impact force, and perceived comfort during walking. Ten healthy females volunteered for the study. The heel heights were 1.0cm (flat), 5.1cm (low), and 7.6cm (high). The heel height effects were examined across five shoe-insert conditions of shoe only; heel cup, arch support, metatarsal pad, and total contact insert (TCI). The results indicated that increasing heel height increases impact force (p<0.01), medial forefoot pressure (p<0.01), and perceived discomfort (p<0.01) during walking. A heel cup insert for high-heeled shoes effectively reduced the heel pressure and impact force (p<0.01), an arch support insert reduced the medial forefoot pressure, and both improved footwear comfort (p<0.01). In particular, a TCI reduced heel pressure by 25% and medial forefoot pressure by 24%, attenuate the impact force by 33.2%, and offered higher perceived comfort when compared to the non-insert condition.

Can Running, Can Movement, Make us better Humans ?

This is a blog post we have placed as a year-end repeat for the last 2 years.  It seemed to bring together many good points and thoughts. We hope you agree.

Today, we would like you all to watch this video and then more importantly read what we have paraphrased below. As we find ourselves here at the end of another year, it is normal to look back and see our path to growth but to look forward to plan for ways to further develop our growth.  Many of you who read our blog are runners, but many of you are also extensions of running, which seems to include most sports. What we mean by that is many of you are coaches or trainers who develop those who run and play sports but many of you are also in the medical field helping people to move and to get out of pain or improve performance.  And still yet we have discovered that some of you are in the fields of bodywork such as yoga, pilates, martial arts, dance and movement therapies.  It is perhaps these fields that we at The Gait Guys are least experienced at (but are learning) and like many others we find ourselves drawn to that which we are unaware and wish to know more in the hope that it will expand and improve that which we do regularly.  For many of you that is also likely the case.  For example, since a number of you are runners we would bet to say that you have taken up yoga or pilates or cross training to improve your running and to reduce or manage injuries or limitations in your body. But why stop there ? So, here today, we will try to slowly bring you full circle into other fields of advanced movement. As you can see in this modern dance video above the grace, skill, endurance, strength, flexibility and awareness are amazing and beautiful.  Wouldn’t you like to see them in a sporting event ? Wouldn’t you like to see them run ? Aren’t you at least curious ? Their movements are so effortless. Are yours in your chosen sport ? How would they be at soccer? How would they be at gymnastics ? Martial arts ? Do you know that some of the greatest martial artists were first dancers ? Did you know that Bruce Lee was the Cha Cha Dance Champion of Hong Kong ? He is only one of many. Dance, martial arts, gymnastics …  all some of the most complex body movements that exist. And none of them simple, taking years to master, but most of which none of us can do. In the year to come we will continue to expand your horizons of these advanced movement practices as our horizons expand. From 3 years of personal study, we already have been experimenting with some of the advanced foot and body movements of dance, incorporating many aspects into our treatment and exercise regimens for our patients, runners and multi-sport athletes. Using things like the latin dance (primarily rumba and salsa) movements to strengthen the hips, core and feet and borrowing from the Cha Cha to improve foot side and cross over step speed and accuracy in some of our NCAA basketball and European soccer players. Even using some of the smooth footwork in the waltz and foxtrot to increase awareness of rear, mid and forefoot strike patterns and the development of rigid and mobile foot positions in our speed athletes.  Why not use this knowledge?  Many of our athletes do not even know their exercises homework are from basic dance principles, until we tell them at the end of a session.  There is a reason why some of the best athletes in the NBA, NFL and other sports have turned to almost secret study of dance and martial arts because there is huge value in it.  Look at any gymnast, martial artist or dancer. Look at their body, their posture, their grace.  It is as if their bodies know something that ours do not.  And so, The Gait Guys will dive even deeper into these professions to learn principles and bring them back to you. After all, everything we do is about movement. Movement is after all what keeps the brain alive. 

Below are excerpts from a great article from Kimerer Lamothe, PhD. She wrote a wonderful article in Psychology Today (link is at the top) on her experience with McDougall’s book “Born to Run” and how she translated it into something more.  Below you will find some exerpts from her work. But at some point, take the time to read the whole article.  But do not cut yourself short now, you only have a little more reading below, take the next 2 minutes, it might change your life, or at least your next run.

We will leave you hear now for 2012 with our gratitude for this great growing brethren and community that is unfolding at The Gait Guys. We have great plans for 2013 so stay with us, grow with us, and continue to learn and improve your own body and those that you work with.  Again, read Kimerer’s excerpts below, for now, and watch the amazing body demonstrations in the video above. It will be worth it.

_____________________

Can Running Make us Better Humans ?….. Here are excerpts from the article by Kimerer LaMothe (these excerpts remain the exclusive property of Kimerer, if you wish you quote or link our article, you must quote and link her article, for it is her work alone.)

http://www.psychologytoday.com/blog/what-body-knows/201109/can-running-make-us-better-humans

“The Tarahumara are not only Running People, they are also Dancing People. Like other people who practice endurance running, such as the Kalahari Kung, dancing occupies a central place in Tarahumara culture. Or at least, it has. The Tarahumara dance to pray, to celebrate life passages, to mark seasonal and religious events. They dance outside where Father God and Mother Moon can see, in patterns consisting of steps and shuffles, taps and hops, performed in a line or a circle with others. And they dance the night before a long running race, while the native corn beer, or tesguino flows.

While McDougall notes the irony of “partying” the night before a race, he doesn’t ask the question: might the dancing actually serve the running? Might it be that the Tarahumara dance in order to run—to ensure the success of their run—for themselves and for the community?

At the very least, the fact that the Tarahumara dance when and how they do is evidence that they live in a world where bodily movement matters. They believe that how they move their bodies matters to who they are and to how life happens. They have survived as a people by adapting their traditional method of endurance hunting (running animals to exhaustion) to the challenges of fleeing Spanish invaders, accessing inaccessible wilderness, and staying in touch with one another while scattered throughout its canyons. As McDougall notes, they have kept alive an ancient genetic human heritage: to love running is to love life, for running enables life.

Yet McDougall is also clear: even the Tarahumara are not born knowing how to run. Like all humans, they must learn. Even though human bodies are designed to flourish when subject to the stresses of long distance loping, we still need to learn how to coordinate our limbs to allow that growth to happen. We must learn to run with head up, carriage straight, and toes reaching for the ground. We must land softly and roll inwardly, before snapping our heels behind us. We must learn to glide—easy, light, smooth—uphill and down, breathing through it all. How do we learn?

How do we learn to run? We learn by paying attention to other people, and taking note of the movements they are making. We learn by cultivating a sensory awareness of our own movements, noting the pain and pleasure they produce, and finding ways to adjust. We learn by creating and becoming patterns of movement that release our energy boldly and efficiently across space. We learn, in a word, by dancing.

While dancing, people open up their sensory selves and play with movement possibilities. The rhythm marks a time and space of exploration. Moving with another heightens the energy available for it. Learning and repeating sequences of steps exercises a human’s most fundamental creativity, operating at a sensory level, that enables us to learn to make any movement in any realm of endeavor with precision and grace. Even the movements of love. Dancing, people affirm for themselves and with each other that movement matters.

In this sense, dancing before the night of a running race makes perfect sense. Moving in time with one another, stepping and stretching in proximity to one another, the Tarahumara would affirm what is true for them: they learn from one another how to run.  They learn to run for one another. They run with one another. And when they race, they give each other the chance to learn how to be the best that they each can be, for the good of all.

It may be that the dancing is what gives the running its meaning, and makes it matter.

Yet the link with dance suggests another response as well. In order for running to emerge in human practice as something we are born to do, we need a culture that values movement—that is, we need a general appreciation that and how the bodily movements we make matter. It is an appreciation that our modern western culture lacks. 

Those of us raised in the modern west grow up in human-built worlds. We wake up in static boxes, packed with still, stale air, largely impervious to wind and rain and light. We pride ourselves at being able to sit while others move food, fuel, clothing, and other goods for us. We train ourselves not to move, not to notice movement, and not to want to move. We are so good at recreating the movement patterns we perceive that we grow as stationary as the walls around us (or take drugs to help us).

Yet we are desperate for movement, and seek to calm our agitated senses by turning on the TV, checking email, or twisting the radio dial to get movement in a frame, on demand. It isn’t enough. Without the sensory stimulation provided by the experiences of moving with other people in the infinite motility of the natural world, we lose touch with the movement of our own bodily selves. We forget that we are born to dance and run and run and dance.

The movements that we make make us. We feel the results. Riddled with injury and illness, paralyzed by fears, and dizzy with exhaustion, our bodily selves call us to remember that where, how, and with whom we move matters. We need to remember that how we move our bodies matters to the thoughts we think, the feelings we feel, the futures we can imagine, and the relationships we can create with ourselves, one another, and the earth.

Without this consciousness, we won’t be able to appreciate what the Tarahumara know: that the dancing and the running go hand in hand as mutually enabling expressions of a worldview in which movement matters.”

Thanks for a great article Kimerer. (entire article here) http://www.psychologytoday.com/blog/what-body-knows/201109/can-running-make-us-better-humans

Wishing a Happy New Year to you all, from our hearts……. Shawn and Ivo

The Gait Guys

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So what do these dogs tell us?

These are pedographs of a 12 year old male who was brought into the office last week by his mother with knee pain, bilaterally, R > L and bilateral hip pain.

Clinical findings are a left tibial and femoral leg length deficiency of over 1 cm; bilateral internal tibial torsion in excess of 40 degrees; no femoral retro or ante torsion.

Gait evaluation revealed moderate rear and midfoot pronation. He leaned to the left during stance phase on the left. Arm swing had bilateral symmetry.

So, what can you tell us about internal tibial torsion?

The tibial torsion angle is measured by looking at the angle of the tibial plateau and the intermaleolar line (see middle picture above). The distal tibia begins in utero having an angle of 0 degrees in the infant an “untwists” to 22 degrees by adulthood (see far right). Tom Michaud does a great job talking about this in this book “Human Locomotion: The conservative Management of Gait Related Disorders”. When it moves less than the requisite amount (possibly due to biomechanical. genetic or environmental influences), you get internal tibial torsion. This means the foot is pointed inward when the knee is in the coronal plane (ie facing straight forward)

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

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

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

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

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

  

Shoe Types and plantar pressures
J Am Podiatr Med Assoc. 2009 Jul-Aug;99(4):330-8. Effect of running shoe type on the distribution and magnitude of plantar pressures in individuals with low- or high-arched feet. Molloy JM, Christie DS, Teyhen DS, Yeykal NS, Tragord BS, Neal MS, Nelson ES, McPoil T. Source

US Army-Baylor University Doctoral Program in Physical Therapy, Ft Sam Houston, TX 78234-6138, USA. Joseph.Molloy@amedd.army.mil

Abstract BACKGROUND:

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

METHODS:

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

RESULTS:

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

CONCLUSIONS:

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


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

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Since the world did not end, you should probably think twice about those motion control shoes….

WE can all agree that there is a time and a place for motion control shoes. For people with chronic ankle sprains or lateral instability (ie, an incompetent lateral compartment; peroneus longus, brevis or tertius), it is neither the time, nor the place.

The lateral ankle is stabilized by both static (ligaments: above lower left) and dynamic (muscles above, lower right) elements. This is often called “the lateral stabilizing complex” The lateral ankle (ie the lateral malleolus) also projects more inferiorly than the medial. This means that when push comes to shove, the ankle is more likely to invert (or go medially) than evert (or go laterally). What protects it? The static component consist of three main ligaments (seen above) the posterior and anterior talofibular ligaments and the calcaneofibular ligaments. The dynamic components are the peroneii muscles. These muscles not only stabilize but also exert an eversion (brings the bottom of the foot to the outside) force on the ankle.

So what you say?

according to one study we found “Using an in-shoe plantar pressure system, chronic ankle instability subjects had greater plantar pressures and forces in the lateral foot compared to controls during jogging.”

Hmmm. Remember the midsole? (If not click here and here for a review) Motion control shoes are medially posted. That means they provide more support medially or  have a tendency to tip the foot laterally. SO, motion control shoes shift forces laterally.

A person with chronic ankle instability has weakness of either the static, dynamic, or both components of the lateral stabilizing complex.

bottom line? make sure folks have a competent lateral stabilizing complex and if they don’t, you may want to think twice about using a motion control shoe.

Ivo and Shawn. Increasing your shoe geekiness coefficient on daily basis!                                                                                                                                                      

Foot Ankle Int. 2011 Nov;32(11):1075-80. Increased in-shoe lateral plantar pressures with chronic ankle instability. Schmidt H, Sauer LD, Lee SY, Saliba S, Hertel J. Source

University of Virginia, 2270 Ivy Road, Box 800232, Charlottesville, VA 22903, USA.

Abstract BACKGROUND:

Previous plantar pressure research found increased loads and slower loading response on the lateral aspect of the foot during gait with chronic ankle instability compared to healthy controls. The studies had subjects walking barefoot over a pressure mat and results have not been confirmed with an in-shoe plantar pressure system. Our purpose was to report in-shoe plantar pressure measures for chronic ankle instability subjects compared to healthy controls.

METHODS:

Forty-nine subjects volunteered (25 healthy controls, 24 chronic ankle instability) for this case-control study. Subjects jogged continuously on a treadmill at 2.68 m/s (6.0 mph) while three trials of ten consecutive steps were recorded. Peak pressure, time-to-peak pressure, pressure-time integral, maximum force, time-to-maximum force, and force-time integral were assessed in nine regions of the foot with the Pedar-x in-shoe plantar pressure system (Novel, Munich, Germany).

RESULTS:

Chronic ankle instability subjects demonstrated a slower loading response in the lateral rearfoot indicated by a longer time-to-peak pressure (16.5% +/- 10.1, p = 0.001) and time-to-maximum force (16.8% +/- 11.3, p = 0.001) compared to controls (6.5% +/- 3.7 and 6.6% +/- 5.5, respectively). In the lateral midfoot, ankle instability subjects demonstrated significantly greater maximum force (318.8 N +/- 174.5, p = 0.008) and peak pressure (211.4 kPa +/- 57.7, p = 0.008) compared to controls (191.6 N +/- 74.5 and 161.3 kPa +/- 54.7). Additionally, ankle instability subjects demonstrated significantly higher force-time integral (44.1 N/s +/- 27.3, p = 0.005) and pressure-time integral (35.0 kPa/s +/- 12.0, p = 0.005) compared to controls (23.3 N/s +/- 10.9 and 24.5 kPa/s +/- 9.5). In the lateral forefoot, ankle instability subjects demonstrated significantly greater maximum force (239.9N +/- 81.2, p = 0.004), force-time integral (37.0 N/s +/- 14.9, p = 0.003), and time-to-peak pressure (51.1% +/- 10.9, p = 0.007) compared to controls (170.6 N +/- 49.3, 24.3 N/s +/- 7.2 and 43.8% +/- 4.3).

CONCLUSION:

Using an in-shoe plantar pressure system, chronic ankle instability subjects had greater plantar pressures and forces in the lateral foot compared to controls during jogging.

CLINICAL RELEVANCE:

These findings may have implications in the etiology and treatment of chronic ankle instability.


all material copyright 2012 The Homunculus Group/ The Gait Guys. Don’t rip off our stuff. PLEASE ASK 1st!

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

The 1st Ray that is!

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

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

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

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

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

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

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

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

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