Asymmetry doesn't matter?

Asymmetry doesn't matter?
There were many people jumping on the Usain Bolt "asymmetry doesn't matter" train in the last few weeks after all the discussion on his scoliosis and leg power differentials. Now nothing but silence.
We think asymmetry matters, and we wrote about it all last week.
What if Bolt were just a little more symmetrical ? Would he have been a little faster ? Is Gatlin faster or just more symmetrical ? Lucky race? I bet Gatlin doesn't think so or care, nor does Coleman. LOL. Fuel for the fire. We will stand our ground however.

We are not pointing fingers or picking on anyone, fact of the matter is we love the good debates that have been going on. That is where the learning occurs. We are always happy to be wrong, as long as we leave a debate smarter than when we went in to it.
#crickets #maybeasymmetrymatters

Addendum worth adding here (from comments below):

Eric A Johnson , asymmetry is the law/rule. How much is too much? No one can answer that. But if we drive a patient towards less asymm and they don't have pain, injury incidence reduces, their chronic complaint becomes less of issue or resolves, or if performance improves...... then maybe, just maybe, their asymmetry mattered. #noguarantees #wishwecouldclone #crystalballs

And . . . if Bolt had won, everyone would be just saying that more proof that asymmetry is ok, ignore asymmetries in your clients.
Fact of the matter is, as we said in our post, that asymmetries are the norm, the rule of law, but that does not mean that asymmetries are not an issue in some people and some athletes. When is an asymmetry too much that it poses an injury risk or a performance loss ? No one knows until we can clone people, but there is a tipping point in everyone where it is just plainly too much to risk. That is the point of the discussion.
So, we are glad Gatlin and Coleman beat Bolt. Only because an older guy beat the King are we having this discussion, thankfully. Which is really what matters here, the discussion, instead of defending ones flag because of one journal article that has a big unknown hanging over it.

We have acquired the asymmetry study below.
We hope to have something to share that helps in the asymmetry dialogue. The authors did quote "To the authors’ knowledge, this is the first study to present the magnitude of asymmetry in sprinters with mean maximal velocity >10 ms-1 " So anyone hanging their hat on one study should consider pulling back on the reigns a little before planting their flag. More research needs to be done.

To clarify our stance, since it became clear in the ensuing debate yesterday that our perspective was not well postured, that we are talking about physical biomechanical asymmetries in muscle strength, power, endurance, skill and torsional issues, functional leg length differences, etc. Not performance asymmetries that may result from these asymmetries. We apologize for our lack of clarity, we all at times assume that others we debate with know what angle we are jousting from, hence why debate is good, to clarify all the factors and find some better answers and common (or uncommon) ground.
We also will assume that most of those debating yesterday from the article's perspective, had likely not read the article either since it was just released and is a fee-based paper.

For those wondering, here were the variables looked at:
"The following variables were included in analyses;
step length, step rate, contact time , aerial time, touchdown angle (for the stance leg), knee separation (assessed as inter-thigh angle) at touchdown, lift-off angle, thigh - and knee angle at lift-off (for the stance leg), maximal thigh flexion, range of thigh motion, rear knee flexion at maximal thigh extension, and horizontal ankle velocity (of the lateral malleolus marker for the soon -to -be stance foot) relative to CoM"

Our stance would be, based off our comments previously, if these things were asymmetrical, could driving the client toward greater symmetry, result in better outcome performance. That was and is, our thought experiment.

 

 

This was a dialogue we had recently and we have been messaged on it numerous times. Don't get too rigid in your beliefs, it might come back to bite you (that goes for us too). It is best we all keep our eyes and minds open. Science moves forward, so don't plant your flag so far in the ground that you can't pull it up when the landscape of knowledge moves the frontline further ahead.

Paraphrased:
Research has not yet provided all the answers to all our questions in the study of the human frame. There are plenty of studies we have all found that are flawed, so we are not going to always agree with research, research is a starting place, a foundation work from, but things change and they change fast sometimes . . . . just because something has not been validly proven yet (or disproven) in research doesn't mean it is not going to be nor does that proposed thought not deserve deeper thought . . . learning doesn't stop at the end of the pen of a researcher who may know a little less on a topic than others. Just because there is a published journal article on a topic doesn't necessarily make it a reliable paper or make it law or a template we must all embrace or "forever hold our peace". Challenging the present facts and knowledge doesn't necessarily always make it "bro science" either.
Question everything while working from a present day base of knowledge. And be ok with being called a bro, it can a compliment , sometimes, and sometimes not by those who may be feeling uncomfortable that their belief system may be quivering in uncertainty from some new paradigms in thought.

 

http://www.tmz.com/2017/08/05/usain-bolt-loses-final-solo-100m-race-justin-gatlin/

Walking: The brain leads the body by one step.

Researchers have discovered that we most accurately hit targets when we see them 1 to 1.5 steps ahead of where we were. This is more difficult that it seems because we are making a plan, and at the same time we're making that plan, we're making a movement based on the stuff that we saw a second and half in the past.
Below this link, you will find our post on projecting and estimating steps. Much along the same lines but with a great video to set it up.

https://www.axios.com/when-walking-the-brain-leads-the-body-by-one-step-1513304440-3035f0bb-a992-403f-b084-51e4205cda58.html
https://thegaitguys.tumblr.com/post/44642195883/the-funny-problem-with-the-stairs-at-brooklyns

Helping the shoes bend where you do.

Sometimes, when someone has a foot that is a half or whole size smaller and the shoe doesn't bend where their 1st MTP joint bends, you have to perform shoe surgery. Rather than throwing a pair of shoes away because its causing pain at the joint (and you have ruled out all other causes and this is the only pair of shoes that bothers them), sacrifice a few hundred miles on the newer shoes and make it bend where your client bends.

ADDENDUM to video:
Sometimes, when someone has a foot that is a half or whole size smaller and the shoe doesn't bend where their 1st MTP joint bends, you have to perform shoe surgery. Rather than throwing a pair of shoes away because its causing pain at the joint (and you have ruled out all other causes and this is the only pair of shoes that bothers them), sacrifice a few hundred miles on the newer shoes and make it bend where your client bends.

ADDENDUM: we recieved a good question about this, as to "Where and how deep etc" to make the cut.

the shoe bends momentarily before the toe bends, so i like to create the cut (start little, just enough for the client to feel the shoe now bends easier and is creating less pressure into the joint) , i like to create the cut about 2mm to where the metatarsalphalangeal joint bends, proximal on the sole of the shoe...... since the shoe will begin to flex at heel lifting before much toe dorsiflexion occurs. But, as ivo said, they are not bending at the regular build in toe break of the shoe (where it naturally breaks/bends) so you will typically be proximal to that toe break interval. And yes, start small, because the cut will grow larger, and often fast........so the shoe will trash out sooner. I encourage folks to return the shoe if it is new, it was a bad shoe fit......but if they have 50 miles or more on it and the shoe is not working, rather than trash them........play surgeon and learn ! The client will most likely say "that was it, the shoe bends easily now, i can toe off comfortably".......... until the cut extends and ruins the shoe. In my experience that is about at another 150 miles

 

Trying again here. VIDEO CASE: Is this lateral compartment weakness ?

Quite simply, there are too many people playing doctor out there that do not have the ability to examine their clients appropriately. Here is another case of just that.
It is clear that this client has left lateral compartment deficits. Or is it too much medial compartment tone ? Your screens and loading tests will not likely show you this specifically, this client may merely present, as they did in this case of left frontal plane hip-pelvis drift and a right cross over step. If you have been with us for awhile, you know these 2 match up when it comes to locomotion. But one must solve the "Why" for the "how" to be accurate (how to fix it).
But, if you are looking for weakness, you will find it here, yes, peronei and lateral gastroc are weak. But is it inhibition or neurologic or frank weakness ? It is because of heightened medial compartment tone ? It could be, thus making one think of possible centrally mediated processes.
And, is the ankle the source or the frontal plane drift (glute weakness) the source ? Cart or the horse ? Chicken or the egg ? You have to examine your clients, on and off their feet, shoes off, socks off (yes, i took the socks off afterwards). Screens are not enough if you are trying to solve problems. Fixing how your client's improper loading is not a fix always, it could merely be teaching a compensation over a compensation to a problem. Be smarter than the rest, get the knowledge to examine your clients deeper , and more specific, function. Then, how they are moving, and the movements that you see that you do not like, will make more sense.
in this case, if you do not address the foot and the hip abductors and pelvis stabilizers, you lose, and so does your client as you build more strength into their asymmetry . . . . eventually leading, possibly, to complaints.

Gait and peripheral arterial disease

When we think of slowing gait we think of the elderly. There is nothing new in this regard and there have been plenty of papers supporting the cognitive decline the coincides with this aging population. There is even correlation to increased fall risk, which matches up with significant fall mortality studies. Reduced, especially right sided, hippocampus volume and function is the current suspect in most research, and it is linked to some impairments in non-verbal memory and the slowing of gait.

Here, we see that PAD (peripheral arterial disease) can also cause a slowing of gait, particularly in stair ascent in this particular study. PAD can cause intermittent claudication pain in the calf and result in altered gait mechanics during level walking as well. The study found that those with claudication walked more slowly than healthy controls. They also found that there was reduced vertical ground reactive forces, reduced knee extensor moment during forward continuance, reduced ankle angular velocity at peak moment and reduced ankle power generation. They were also able to determine that the slower gait was related to the claudicated limb, that limb was the one that set the speed of gait. In other words, the system down regulated to the affected limb's capability. The study highlighted the importance of maintaining plantarflexor strength and power in those with peripheral arterial disease with effective claudication.

Sagittal plane joint kinetics during stair ascent in patients with peripheral arterial disease and intermittent claudication. Stephanie L. King, Natalie Vanicek, Thomas D. O’Brien

Degenerative Achilles tendons have reduced stiffness.

On yesterday's podcast 127 recording (launch in 3 weeks), we go down this rabbit hole. A worthy hole.
This is important stuff, if you are treating people, (unlike Joe Rogan and the Scibabe, soft slap there, they should use their platform to interview really smart people when it comes to medicine :), you need to know this stuff.

"Achilles tendon, when degenerated, exhibits lower stiffness. This local mechanical deficit may be compensated for by an alteration of motor commands from the CNS. These modulations in motor commands from the CNS may lead to altered activation of the agonist, synergist and antagonist muscles. "

https://www.ncbi.nlm.nih.gov/pubmed/26046962

Jumping is a skill. Don't do it like this.

Jumping is a skill. Look at his right knee, i wouldnt want to be his knee. The knee is a sagittal hinge, not a lateral hinge. This is going to likely lead to a Valgus Thrust degenerative joint. Jumping is a sagittal plane skill first , master that first.
It just hurts to watch his right knee !

http://www.menshealth.com/…/best-core-and-cardio-workout-men

*Video Gait demo: The couple in the hats, are they in phase or out of phase?

*Video Gait demo: The couple in the hats, are they in phase or out of phase?
Have you ever wondered why people who walk together quickly synchronize their gaits ?

The synchronization between walking partners is more complex than it seems on the surface. There are two types of synchronization, in-phase (both person’s right foot move forward at the same time) and out-of-phase synchronization (where the right foot moves forward with the partners left foot). You can see in the video above that the couple has subconsciously fallen into an Out-of-Phase synchronization.

There are multiple factors and communication mechanisms occurring. There are auditory mechanisms in play such as the sound of the other persons foot fall. There are even visual mechanisms through peripherally seeing your partners arm swing and foot fall which encourages the imitation synchronization. However, the strongest in-phase synchrony occurred in the presence of tactile feedback meaning hand holding or embracing each others waist from behind, which couples often do when walking more slowly, seem to create a stronger synchrony. When this tactile component is engaged between two walkers it is plausible that the upper and lower limbs move more freely when paired up, particularly with arm swing.
Read on, there is more to it here in an post we did awhile back. . . . link below

https://thegaitguys.tumblr.com/post/29333686230/have-you-ever-wondered-why-people-who-walk

https://youtu.be/05XtMtap3Yg

Have you ever wondered why people who walk together quickly synchronize their gaits ?

From healthy heart cells that synchronize to a single beat, to women in school dormitories or work places who synchronize their menstrual cycles, to fireflies who begin blinking in synchrony when they all perch in the same tree synchronization is something that is abundant in nature.  It is no wonder that we find synchronicity in one of our most primitive and frequent motor patterns, walking together with someone shows the same synchronicity phenomenon.

Hold the hand of your favorite person and go for a walk. Within a few strides your gaits will synchronize. Is it because it is easier ? Is it because when synchronized the arm swings will match thus making it easier and more effortless to hold hands ?  Does the same effect occur if you are not holding hands ? Studies have concluded that although it does not happen all of the time, they found it occurs in almost 50% of the walking trials even among couples who do not usually walk together. This is far too high a percentage to not make it a statistically significant finding.

The synchronization between walking partners is more complex than it seems on the surface.  There are two types of synchronization, in-phase (both person’s right foot move forward at the same time) and out-of-phase synchronization (where the right foot moves forward with the partners left foot).  You can see in the video above that the couple has subconsciously fallen into an Out-of-Phase synchronization, then after the tide splash that throws them off within just a few steps they fall right back into Out-of-Phase synchronization and hold it in that state.  There are multiple factors and communication mechanisms occurring. There are auditory mechanisms in play such as the sound of the other persons foot fall.  There are even visual mechanisms through peripherally seeing your partners arm swing and foot fall which encourages the imitation synchronization. However, the strongest in-phase synchrony occurred in the presence of tactile feedback meaning hand holding or embracing each others waist from behind, which couples often do when walking more slowly, seem to create a stronger synchrony.  When this tactile component is engaged between two walkers it is plausible that the upper and lower limbs move more freely when paired up, particularly with arm swing.

What is thought to happen is that one partner dominates the lead in the gait, just as in dancing, one person is the leader and the other is the follower. The lead partner’s lower limbs determine the movement of their arms, which in turn when holding hands, sets the arm movement pattern in the partner then determining the leg swing and stance phases. Thus, synchrony is achieved. 

However, it is important to note that many of the studies were clear to mention that even in non-tactile cases, many of the gaits of two people walking together are synchronized. This was likely due to the visual and auditory parameters however height, leg length cadence etc could also play into those successful non-tactile synchrony cases.

These are interesting findings at 50% because it is very unlikely that any two people are of the same height, leg length, cadence, stride and step length.  These are all parameters that are likely to change the likelihood of gait synchrony.  Zivotofsky found that “even in the absence of visual or auditory communication, couples also frequently walked in synchrony while 180 degrees out-of-phase, likely using different feedback mechanisms”. The studies below discuss many issues of this synchrony but it is perhaps most significant in clinical rehabilitation cases or in early or moderately advanced movement impairment disorders and diseases these findings may partially explain how patients can enhance their gait function when they walk with a partner or therapist.  It is in these movement impairment syndromes and diseases where the central processing and Central Pattern Generators (CPG’s) are diseased leaving them with the need for other cues such as those discussed here today, auditory, visual and tactile. 

You may have read our previous blog articles on arm swing and how intimately they are anti-phasically (opposite) paired with lower limb swing.  But today’s blog post article took limb swing to another level.  Stay tuned for more on arm and leg swing in human movement.  If you wish to read our other works on arm and leg swing and their deeper effects on gait, go to our blog www.thegaitguys.tumblr.com and enter the words “arm swing” into the SEARCH box.

Shawn and Ivo…….. taking gait far beyond what you learned about it in school.
______

References used:


J Neuroengineering Rehabil. 2007; 4: 28. The sensory feedback mechanisms enabling couples to walk synchronously. An initial investigation.  Ari Z Zivotofsky and Jeffrey M Hausdorff  Published online 2007 August 8. doi:  10.1186/1743-0003-4-28

Hum Mov Sci. 2012 Jun 22. [Epub ahead of print] Modality-specific communication enabling gait synchronization during over-ground side-by-side walking. Zivotofsky AZ, Gruendlinger L, Hausdorff JM.Gonda Brain Research Center, Bar-Ilan University, Ramat-Gan 52900, Israel.

 

Video Gait Case: internal tibial torsion

Real time VIDEO of internal tibial torsion (at least highly suspect, the guy wouldn't stop for me to examine him :) Knee appears in the sagittal plane, foot, well, not so much.

Need a refresher on tibial torsion ? Here ya go !
https://thegaitguys.tumblr.com/post/43648553025/yes-we-are-all-twisted-part-3-continued-if

Crossing over, running on the line. The narrow step width, we know you do it.

Screen Shot 2018-01-27 at 10.48.00 AM.png

This one, on archive Friday, is a great follow up to our cross over video case earlier this week. Crossing over gait causes increased lateral foot strike, further than normal heel strike (if you choose or naturally deviate towards that type of strike) and often maintenance of lateral foot loads even into midfoot loading response times. It can, and often does, lead to greater, faster, more abrupt pronation and as we discussed earlier this week, troubles with efficient high gear toe off (medial foot/big toe off). It also requires more frontal plane pelvis and hip stability as we discuss here today on a blog post from 2014. The frontal plane will be challenged for its durability because it is obvious from the photo here, that the hip, knee and foot are not vertically stacked, not even remotely. Do you have enough frontal plane stability to endure the liabilities in this typically more efficient narrow step width style of running ? That is the big question. If your ITB is chronically tight, there is reason. if you run this way and have problems later into your long runs, there is a reason (endurance in even the muscles fade, not just cardiovascularly). Read on . . . https://thegaitguys.tumblr.com/post/86411021079/saucony-line-running-and-crossing-over-we-are
 

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 ! :-)

Video Gait Case: Cross over gait, low gear toe off.

Video case: Cross over gait and low gear toe off.
I have just made the assumption that this was a forgone conclusion, an obvious link. But after a dialogue with a very intelligent gait person, a debate occurred around the cross over gait and i suddenly realized that they did not understand normal gait mechanics and thus could in no way possible understand pathologic gait mechanics like the cross over gait, and in particular high gear toe off vs low gear toe off and all they both encompass. Ivo and i say it all the time, if one does not solidly know normal mechanics it is going to be difficult to truly understand pathologic mechanics. Here today, in this brief example, i hope i make a firm point. Sorry for the quality of the video, but the point should be clear. - Shawn

addendum: ;
The Gait Guys try it yourself, walk on a single straight line and try to effectively "high gear" (big toe/medial tripod) toe off. IT AIN'T GONNA HAPPEN DAWG ! Unless of course you go into a ridiculous degree of increased foot progression angle. But now you are compensating around a compensation.......the death spiral.

Video Gait Case: Hip pathology

Video case:
another gait case from downtown Chicago. Pathology is all around us, if we are looking for it. Hopefully you are as tortured as we are.

-torso lean over the likely painful right hip (this is a compensated Trendeleburg, as opposed to an uncompensated, know the difference !)
- which side would a cane be best used on ? right or left ? (answer" left)
- she is carrying her purse on the wrong shoulder, it should be in her right hand, reducing compressive demand on the gmedius. The more the gmedius has to contract, the more compression it creates across the joint line, and if the hip is OA, it will create more pain). A cane and load in the right hand will passively manage the loads rather than actively doing it through the gmedius contraction and compression.
- heavy plunking down on the left leg. (careful not too much quad tone is developing, it can create some PF joint compression and aberrant loads and render left knee pain, that is the last thing she needs).
When you are walking about the world, play the game.
See it, and quickly gather the info, and sharpen your clinical reason skills. Get these concepts down, so you do not have to think through them in the clinic, instead, you just goto work fixing them.
If you tried to ease her burden with a sole lift (dont be a fool and use a heel lift), which side would it help her most on ? Answer: left.

Gait Video case: Foot drop, a closer look.

I hope my final thoughts in today's important gait video will be profound to you as a clinician. It is the soft subtle presentations that are the tough ones, but the same messages are there, if you spend the time to assess for them.
* Remember, what you see in your client's gait is not their problem (as is obvious in today's video), instead you see how they are moving around their deficits. This is a key point we hammer home all the time. If you are making recommendations for your clients on how to move differently through corrective exercises that you THINK they need, merely because you see something in their movement that you do not like, you are very likely going to be fooled. You are not doing your client great service if that is your methodology. For example, telling this guy to engage his left tibialis anterior and lift his toes is the obvious visual correction, but the fact of the matter is, he cannot. So, what you see is how he has figured out how to move through the world, his compensation.
And for those who wish to argue, yes, hard neurologic deficits like you see here are not fixable. In this case, yes, you need to help them gain more skill endurance and strength in a better armored pattern for protective durability. But in many people, those without hardwired neuro or orthopedic deficits, you should be looking to fix their deficits, not merely fix aberrant movements that you just do not think LOOK good.

Unilateral heightened toe extensor tone.

Look at this foot. What do you see ? See the asymmetry ? This is a perfect case to prove our point, for those out there that love the short foot exercise, that insist on towel scrunches, marble pick-ups, or just mere foot rolling on the ball. These things are useless in some cases, arguably to us, much of the time actually. This is about having sufficient foot integrity, normal heel rocker, ankle rocker, forefoot rocker mechanics, and especially in this case, a NORMAL balance between the long and short flexors and extensors. These 4 must work together in harmony, and this is clearly not happening on the left foot. Head on over to this Archived blog post from 2014, and learn what is wrong here. One has to understand it, to fix it. And throwing a short foot regimen, or pilates foot work at it or even more flexor tone into this foot will not fix this. Exercise prescription is supposed to be specific, not a shot gun approach of "try this exercise", lets see if it helps. A 5th grader can give that advice, sadly it is more the industry norm at times. Yes, every exercise is a test, but do not be mistaken that every test is the exercise.

https://thegaitguys.tumblr.com/post/85726861424/unilateral-heightened-toe-extensor-tone-what-do

Unilateral heightened toe extensor tone.

What do we have here ? Well, it is obvious. The left foot is showing increased short extensor tone (EDB: extensor digitorum brevis) and heightened long flexor tone (FDL: flexor digitorum longus). This is the classic pairing for hammer toe development.  We also know from this post (link) and from this post (link) that this presentation is closely related with lumbrical weakness and distal fat pad migration.

So, at an assessment took we like to play games. Mental games to be precise. When we see something like this we immediately begin the mental gyrations of “what could have caused this, and what could this in turn be causing”. Remember, what you see is often not the problem, rather your clients compensation around the problem.  In this case, what goes through your mind ?  Without deep thought, our knee jerk thoughts are:

  • possible loss of ankle rocker dorsiflexion (the increased EDB tone can be recruited to help drive more ankle dorsiflexion indirectly)
  • plantar intrinsic weakness ?
  • flip flops or slip on shoes where the heel is riding up and down inside the shoe/sloppy fit ?  (initiating a gripping response from the FDL)
  • weak tib anterior (recruiting EDB to help)
  • weak peroneus tertius (recruiting EDB again)
  • Ankle /foot instability (more FDL gripping will help gain ground purchase)
  • lateral ankle instablity (same thing, more gripping)
  • Weak gastrosoleus (since the FDL is a posterior compartment neighbor it can kick into high gear and help with posterior comparment function, we have a whole video case based around this issue, check this out ! )
  • premature departure off of the good side leg, and thus an abrupt loading response onto this affected side can challenge the frontal plane of the body and thus require more grip response at the foot level.
  • how about simple weakness of the lumbricals or FDB , the short flexors. The long flexors will have to make up for it and present like this.  
  • the list goes on and on … .

These are just some quick cursory thoughts, and by NO means a complete exhaustive list.  Just some quick thoughts.

But what about hip function ?  if ankle rocker is blocked in terminal stance and the FDL fire like this what will that do to hip extension ? Well, heel rise will be premature because of the limitation and thus hip extension will be abbreviated. Thus glute function will be impaired to a degree.  This can become a viscous cycle, each feeding off of each other.

This diagnostic stuff is a tricky and difficult game. If you think you can diagnose or fix a problem from just changing what you see you are mistaken, unless you like driving compensation patterns and future injuries into your clients.   There must be a hands on examination and assessment with an intact educated brain attached to the process.

Just some mental gymnastics for you today.  

Dr Shawn Allen, one of the gait guys

Gluten ataxia

Gluten ataxia, hypothyroid ataxia and others: The wobbly, unsteady client. Do not dismiss it.

Gait Ataxia, it is not uncommon especially in the aging population and it can come from many sources.
We have talked about it several times in the past, thyroid dysfunction can affect the cerebellum.
"Acquired cerebellar ataxia has been described with hypothyroidism, and is typically reversible by thyroid hormone replacement therapy. The cerebellar dysfunction has been attributed to metabolic and physiological effects of the endocrine disorder. "
The cerebellum is one of the main CNS targets of autoimmunity. Immune-mediated cerebellar ataxias include gluten ataxia (search our blog for this one), paraneoplastic cerebellar degeneration, GAD antibody associated cerebellar ataxia, and Hashimoto’s encephalopathy.

Progressive non-familial adult onset cerebellar degeneration (PNACD) will have raised antithyroid antibodies (Hashimoto's/autoimmune thyroiditis), and other autoimmune manifestations, in the absence of hypothyroidism and may express cerebellar disorder from the endocrine dysfunction.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1737486/

Knee flexion in gait loading. Heeled shoes do things.

Watch this video, you have likely seen it already but did you notice it ? You will have to fast forward to 1:40 to see the video that applies to this screenshot here today.
How much knee flexion should occur during the initial loading response ? In this walking gait video, if you look closely enough, her high heeled shoes are forcing her to load in a what is technically a midfoot stride (because of the high heel) when in fact she is truly loading initially in a forefoot load, ie. plantarflexion. This abrupt load is forcing her to dampen the load with a quadriceps eccentric (if you watch closely enough, the knee flexes every time during loading, more than it should). Normally, in flat-er shoes, this knee eccentric is basically hidden (it is almost an isometric), it should never be this obvious unless one's quads are truly too weak. To be fair, the shoes are propping her into anterior pelvis tilt, as these high heeled shoes always do, which promotes lower abdominal challenges and premature quad loading, and delayed glute loading (don't believe us? stand up, dump into an anterior pelvic tilt and increased lordosis and try to engage your glutes. Nadda ! So the loading shifts into the quads).
Welcome to another ramification of high heeled shoes, again.
Admittedly, this lady does a great job. Her belt line stays pretty neutral and doesn't dip on each loading response and she is in good control. Ivo and Shawn on the other hand are terrible in their pumps :)

Sprinters, and those who forefoot load during running, are you surprised with anterior knee pain when it comes on, or achilles pain or calf tightness when the calf fatigues and can no longer hold you in adequate plantarflexion ? How about low back pain or tightness after runs ? No, you should not be surprised is the correct answer (unless you have enough durability in the quad and calf, and lower abdominals to sustain the length of your workouts, over and over and over.

Step width, length and gait economy.

We have talked about step with hundreds of times it seems. We get asked all the time about optimal or proper step width in our runners, especially the ones that have a tendency to drop into the higher risk category of "cross over" gait. We like to refer them to our standard reply, "many good things happen with increasing your step width, but there is no need to go beyond the hip distance width, no wider than the hips. You should find more gluteal activation there. However, this is less economical than a narrower step width. But, the narrower the step width, you are juggling the increased economy with increased liability (for injury) and riskier biomechanics. One must earn their way into the higher economy narrow step width with gaining durability in these potentially riskier narrow step with mechanics. Failure to do so is a choice taken at your own risk." This article suggest costly risks to a narrow step width as well.

From the Shorter Abstract

"Humans tend to walk economically, with preferred step width and length corresponding to an energetic optimum. In the case of step width, it is costlier to walk with either wider or narrower steps than normally preferred. Wider steps require more mechanical work to redirect the body's motion laterally with each step, but the cost for narrower steps remains unexplained. Here we show that narrow steps are costly because they require the swing leg to be circumducted around the stance leg. And, we could not agree more. There is definitely a sweet spot for every runner, finding it, and earning the durability required to fend off injury is where the magic lies. RAther than tell your runners where to place their feet , thus you defining their step width, give your clients the appropriate hip and frontal plane stability work to find their low risk sweet spot. After all, most of the foot posturing placement is dictated from the hip and pelvis mechanics, as we have written about extensively previously.

Gait Posture. 2017 Mar 23;54:265-270. doi: 10.1016/j.gaitpost.2017.03.021.

The high cost of swing leg circumduction during human walking.

Shorter KA1, Wu AR2, Kuo AD3.

https://www.ncbi.nlm.nih.gov/pubmed/28371740

Glute fatigue in low back pain.

Sagittal trunk flexion and extension in patients with chronic low back pain.

The study found the duration of gluteus maximus activity was shorter in the back pain patients than in controls during the trunk flexion (p<.05), and it ended earlier during extension. Nothing new here for many of our followers, but it is always worth discussing.

We have talked about the fatigue factor and endurance factor of the paraspinals in low back pain in previous podcasts, maybe a year or two ago. But, in looking for something else in particular today, I came across this article from 2000.
It once again suggests the critical function of the glutes, all 3 divisions and that they do play multiple parts other than just hip stability and movement. We see plenty of clients who have poor development of the upper iliac and sacral divisions of the glute max. This could be from anterior pelvis tilt presentations, faulty movement patterning, or even failure to get to end range hip extension to work on developing that portion of the muscle. Regardless, this once again proves that we are an under-developed glute species and all this sitting is a problem, and even the standing desk trend, will not fix this. The body must move, it must be loaded through to the full range of motion and we must incorporate compound movements with load if we are to get even close to the opportunity to see folks with healthy glutes and thus healthy hips and spines.

"RESULTS:
During early flexion, lumbar paraspinal and biceps femoris were activated simultaneously before gluteus maximus. At the end of flexion and during extension all investigated muscles were activated and relaxed in order. Lumbar paraspinal and biceps femoris muscles were activated in a similar order in low back pain patients and healthy controls during flexion and extension. However, the duration of gluteus maximus activity was shorter in the back pain patients than in controls during the trunk flexion (p<.05), and it ended earlier during extension. Active rehabilitation did not change the muscle activities of lumbar paraspinal and biceps femoris in the back pain patients, but in the measurements after rehabilitation the onset of gluteus maximus activity occurred later in flexion and earlier in extension."

"CONCLUSIONS:
The activity of the gluteus maximus muscle during the flexion-extension cycle was reduced in patients with chronic low back pain. The gluteal muscles should be taken into consideration in the rehabilitation of these patients." - Leinonen et al

Arch Phys Med Rehabil. 2000 Jan;81(1):32-7.
Back and hip extensor activities during trunk flexion/extension: effects of low back pain and rehabilitation.

Leinonen V1, Kankaanpää M, Airaksinen O, Hänninen O.
https://www.ncbi.nlm.nih.gov/pubmed/10638873

Kinematic changes furing running-induced fatigue

imagine that.... core endurance can affect running performance.

Let us see ...as you start to fatigue, you have a tendency to bend forward more at the waist. This is probably due to not only decreased quadriceps/hamstrings ratios but also decreased abdominal/lower back extensor endurance ratios. Of course, we could say that asyou fatigue, you become more quadriceps dominant and less gluteal dominant, which would also be correct.

Ankle eversion also increases as you fatigue. No surprise here. Think about the action of your gastroc/soleus group as the medial gastroc acts to invert the ankle and help promote supination, particularly after mid stance. Also think about all the posterior compartment musculature of the lower leg which contract eccentrically during the first phase of gait to assist in deceleration of pronation. From about mid stance on, the extensors should activate, along with the foot intrinsics to assist in providing a stable base. As we fatigue, this mechanism too appears to begin to fail.

Moral of the story? Keep your core in shape and do lots of endurance work!

https://www.ncbi.nlm.nih.gov/pubmed/23790535

Jumping height seems to depend on limb position.


In this study of 12 classical female ballet dancers, jump height was tested in both turn out and in a neutral hip position. This study was essentially looking at the effects of external hip rotation turn out on lower limb kinematics. The study seemed to control for forward trunk lean, but it is unclear if this included anterior or pelvis tilt pre-posturing. After all, we know very well that anterior pelvis tilt (APT) will significantly inhibit gluteal function (go ahead, dump into APT and try to fire your glutes ! Nadda !)

Here are the study results:
"The dancers jumped lower in the TJ (turn out) than in the NJ (neutral). The knee extensor and hip abductor torques were smaller, whereas the hip external rotator torque was larger in the TJ than in the NJ. The work done by the hip joint moments in the sagittal plane was 0.28 J/(Body mass*Height) and 0.33 J/(Body mass*Height) in the TJ and NJ, respectively. The joint work done by the lower limbs were not different between the two jumps. These differences resulted from different planes in which the lower limb flexion-extension occurred, i.e. in the sagittal or frontal plane. This would prevent the forward lean of the trunk by decreasing the hip joint work in the sagittal plane and reduce the knee extensor torque in the jump."

So, when was the last time your sport allowed you to jump cleanly from the neutral hip and pelvis position? Not likely right ?! So, our rehab and our training must include non-neutral drills and skills, since that is where we live most of the time in our sporting and active lives.

Sports Biomech. 2017 Mar;16(1):87-101. doi: 10.1080/14763141.2016.1205122. Epub 2016 Jul 14.
Comparison of lower limb kinetics during vertical jumps in turnout and neutral foot positions by classical ballet dancers.

Imura A1, Iino Y1.
https://www.ncbi.nlm.nih.gov/pubmed/27418231