When the big toes head...East? Whats the deal?

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What is this?

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A sandal gap deformity or hallux varus creates an expanded first interspace between the hallux and the rest of the toes. It is a likened to the gap caused by wearing a sandal but is actually a normal variant. It can occasionally be developmental. In the fetus, it can be a soft marker for other fetal anomalies such as Downs syndrome, an amniotic band or ectrodactyly. It’s considered benign, however in this individual could have been developmental.

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Notice how he has external tibial torsion (when his knees are pointing forward his feet point to the outside). External tibial torsion generally, because of the orientation of the foot, causes the center of gravity to fall medially thus the need for something to push and stabilize you more laterally, such as toes two through five abducting : )

Dr Ivo Waerlop, one of The Gait Guys

#halluxvarus #strangelookingfeet #hallux #thegaitguys #sandalgapdeformity





Barp EA, Temple EW, Hall JL, Smith HL. Treatment of Hallux Varus After Traumatic Adductor Hallucis Tendon Rupture. J Foot Ankle Surg. 2018 Mar - Apr;57(2):418-420.

https://radiopedia.org/articles/sandal-gap-deformity?lang=us

Munir U, Morgan S. Hallux Varus. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019 Jan-.
2019 May 6.

Ryan PM, Johnston A, Gun BK. Post-traumatic dynamic hallux varus instability. J Clin Orthop Trauma. 2014 Jun;5(2):94-8. doi: 10.1016/j.jcot.2014.05.005. Epub 2014 Jun 15.

Sixth toe disease...That growth on the outside of your foot… Or on somebody’s foot is coming to see you…

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You know what we’re talking about. That extra growth on the lateral aspect of the foot that happens way too often and many of your clients. A Taylor’s bunion or sometimes referred to as a “bunionette”. 

What is the usual fix?

Usually in a ski boot or hiking boot, they blow out the lateral side of the shoe. This is usually not a good fix because most of these folks have internal tibial torsion and somewhat of a forefoot supinatus/varus.

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The internal tibial torsion places the knee outside the saggital plane and an arch support without a forefoot valgus post will just push it further out, creating a conflict at the knee. The forefoot supinatus and/or varus places them on the outside of the foot as well. Remember, most of these folks are ALREADY on the outside of the foot and the foot wants to migrate laterally...so creating more space just means it migrates farther. Good thought, doesn’t work that way.

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So what did we do?

  • We created a valgus post for the forefoot (see picture above) tapering from lateral to medial and to help “push“ the distal aspect of the first ray down (because there was motion available that was not being used)

  • We gave him exercises to help descend the first ray like the extensor hallucis brevis exercise, toe waving as well as peroneus longus exercises

  • We gave him plenty of balance and coordination work

    Dr Ivo Waerlop, one of The Gait Guys




#6thtoe #internaltibialtorsion #forefootvarus # forefootsupinatus #gaitanalysis #thegaitguys







Podcast 149: A runner's podcast. Many things running and biomechanics.


Links to find the podcast:
Look for us on iTunes, Google Play, Podbean, PlayerFM and more.
Just Google "the gait guys podcast".

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www.thegaitguys.com
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doctorallen.co
summitchiroandrehab.com
shawnallen.net

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

Our podcast is on iTunes and just about every other podcast harbor site, just google "the gait guys podcast", you will find us.

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http://thegaitguys.libsyn.com/a-runners-podcast-many-things-running-and-biomechanics
http://directory.libsyn.com/episode/index/id/10506122



Show notes:


Exercise matters
3 months of exercise training reprogrammed the epigenetics of sperm DNA in healthy young men. Exercise silenced genes in sperm DNA involved in schizophrenia, Parkinson's disease, cervical cancer, leukemia, and autism
https://www.ncbi.nlm.nih.gov/pubmed/25864559?dopt=Abstract
Epigenomics. 2015 Aug;7(5):717-31. doi: 10.2217/epi.15.29. Epub 2015 Apr 13.
Genome-wide sperm DNA methylation changes after 3 months of exercise training in humans.
Denham J1, O'Brien BJ2, Harvey JT2, Charchar FJ

Footstrike doesnt matter?
https://www.outsideonline.com/2397214/foot-strike-running-study

Adaptation of Running Biomechanics to Repeated Barefoot Running: A Randomized Controlled Study - Karsten Hollander, Dominik Liebl, Stephanie Meining, Klaus Mattes, Steffen Willwacher, Astrid Zech, 2019
https://journals.sagepub.com/doi/full/10.1177/0363546519849920
Is There an Economical Running Technique? A Review of Modifiable Biomechanical Factors Affecting Running Economy.
Moore IS. Sports Med. 2016.
https://www.ncbi.nlm.nih.gov/m/pubmed/26816209/

Running Technique is an Important Component of Running Economy and Performance.
https://www.ncbi.nlm.nih.gov/m/pubmed/28263283/
Folland JP, et al. Med Sci Sports Exerc. 2017.
https://journals.sagepub.com/doi/full/10.1177/0363546519849920

Important to note though than less vertical oscillation is associated with better economy within groups of distance runners, eg ncbi.nlm.nih.gov/m/pubmed/28263… ; ncbi.nlm.nih.gov/m/pubmed/26816… compliant tendons but greater leg stiffness is the goal for distance runners, correct?

This video shows how end. runners compliance & economy are achieved by greater vertical excursions vs. sprinters who hit hard, get off the ground fast and burn more energy.
https://www.nytimes.com/video/sports/100000004379956/identifying-the-best-way-to-run.html

typically have peak vertical forces of 2.5-3.0 times body weight to offset gravity during contact portion of the stride.
https://www.youtube.com/watch?v=hEnIbklXOiU

Effects of footwear midsole thickness on running biomechanics
Sports Medicine and Biomechanics
Mark H.C. Law, Eric M.F. Choi, Stephanie H.Y. Law, Subrina S.C. Chan , Sonia M.S. Wong, Eric C.K. Ching
https://www.tandfonline.com/doi/abs/10.1080/02640414.2018.1538066?journalCode=rjsp20

Knee muscle forces during walking and running in patellofemoral pain patients and pain-free controls.
Thor F.Besiera, Michael Fredericsona, Garry E.Gold, Gary S.Beaupréd, Scott L.Delp
Journal of Biomechanics Volume 42, Issue 7, 11 May 2009, Pages 898-905
https://www.sciencedirect.com/science/article/abs/pii/S0021929009000396

The Gracilis: Have you considered it in your medial knee pain patients?

The gracilis is the 3rd, seldom mentioned contributor to the pes anserine when it comes to knee pain. It lives in the medial compartment of the thigh and helps to add stability to the medial stabilizing complex of the knee.

image credit: https://en.wikipedia.org/wiki/File:Slide3rrr.JPG

image credit: https://en.wikipedia.org/wiki/File:Slide3rrr.JPG

During an ideal gait cycle, the gracilis tonically contracts throughout stance phase with bursts from terminal swing through initial contact and again from pre swing to initial swing; it is very similar to the adductors in this respect

The gracilis is a superficial muscle on the medial thigh, running from the the pubic symphisis and upper pubic arch to the pes, sandwiched between the sartorius and semitendinosis. The muscle adducts, medially rotates (with hip flexion), laterally rotates, and flexes the hip , and also aids in flexion of the knee. It can be called upon as a thigh flexor (as can the sartorius) when the abs (particularly the external obliques) do not initiate thigh flexion and the TFL, rectus femoris and iliopsoas groups are dysfunctional. Gracilis dysfunction may contribute to medial knee pain when the thigh needs help flexing. We see this particularly on people with excessive mid foot pronation when the foot remains on the ground too long and need some “help” or a “jump start” to initiate thigh flexion.

Think about this “unsung hero” next time you have a recalcitrant medial knee pain patient.

 

Gupta, Aman & Saraf, Abhinesh & Yadav, Chandrajeet. (2013). ISSN 2347-954X (Print) High-Resolution Ultrasonography in PesAnserinus Bursitis: Case Report and Literature Review. 1. 753-757. 

Gray H:  Anatomy of the Human Body  Lea and Febiger, Phildelphia and New York 1918

 Michaud T: in Foot Orthoses and Other Forms of Conservative Foot Care Williams & Wilkins, 1993 Pp. 50-55

 Michaud T: in Human Locomotion: The Conservative Management of Gait-Related Disorders 2011

OTS: Over Training Syndrome. Do you have any of these symptoms ? A blog post & 2 podcasts for you on the topic.

photo: courtesy of pixabay.com

photo: courtesy of pixabay.com

Made famous in the beginning, first it was Alberto Salazar.  Now, just in the last decade it has been Anna Frost, Anton Krupicka, Geoff Roes, Kyle Skaggs, even Mike Wolfe. One by one they have fallen, to OTS.  More frighteningly, how many more have fallen to OTS that we never hear about? How many hundreds or thousands walking amongst us have OTS ? If you are a distance or heavy volume training athlete, do not brush off or take lightly what I have complied here today.


OTS, "Overtraining syndrome" is its name, but perhaps a better one would be "Insufficient Recovery Syndrome".  To use the broadest of terms, this is a self-generated, self-perpetuating dis-ease of one's own homeostasis. To be clear, there is a continuum here of multi-system failure, softer less severe forms of OTS. These less damaged states are referred to as Overreaching syndrome (OR). There are two forms of Overreaching syndrome, Functional OR and Nonfunctional OR. Nonfunctional OR shows decreases in performance for weeks to months while OTS being more severe and requiring months to years for recovery despite rest.

Here are 2 podcasts for you on the topic:

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Listen to Sweat Science: The Mysterious Syndrome Destroying Top Athletes from Outside Podcast in Podcasts. https://podcasts.apple.com/us/podcast/outside-podcast/id1090500561?i=1000442759399

Listen to Podcast 121: Carrying things, Overtraining Syndrome, Ankle Rocker and more from The Gait Guys Podcast in Podcasts. https://podcasts.apple.com/us/podcast/the-gait-guys-podcast/id559864138?i=1000384117922



Over the past 10 years the best of the best are falling, one by one, victim to "too much".  They have just pushed themselves too much, too far, too long. It is the latest biggest thing in running these days, how far can you run ? Marathons are no longer enough for some, they have to see if 50 miles or 100 miles, or more, are enough and that means running 100-160 miles a week. And what is even more scary, some of these runners are in high school and college, they are still growing kids.

The physiology of these people is failing, truly. Some might suggest they in some respects showing signs of a slow death.  “OTS is one of the scariest things I’ve ever seen in my 30 plus years of working with athletes,” says David Nieman, former vice president of the American College of Sports Medicine. “To watch someone go from that degree of proficiency to a shell of their former self is unbelievably painful and frustrating.” - Meaghen Brown Jun 12, 2015.  Outside online. 

The first reference in which OTS was suggested was by a researcher and athlete named Robert Tait McKenzie.  In his 1909 book, Exercise in Education and Medicine, he mentioned a “slow poisoning of the nervous system which could last weeks or even months.” Then in 1985 South African physiologist professor Timothy Noakes discussed what appears to be the same condition in "The Lore of Running". Runners examined by Noakes had so over exerted themselves that both mind and body were failing.

OTS is truly a deeper problem. This is an immune, inflammatory, neurologic and psychological problem as best as anyone can tell.  In essence it seems the body is slowly dying. The body's parasympathetic nervous system, the system that counteracts the ramping up of the sympathetic nervous system, fails to properly respond to bring the systems back into balance. This means that many of the physiologic responses to activity fail to properly return to baseline. This means that blood pressure, heart rate, breathing, digestion, adrenal and hormonal rhythms amongst many other things go awry. Even other important things begin to decline, things like normal restful sleep, sometimes even insomnia, libido decline, metabolism dysfunction, appetite problems and even heart rate recovery and recurrent colds and viral infections.  We are talking about multi-system failure in these people, and this is serious business. The problem is, these athletes do not listen to the signals until it is too late and they are in full blown multi-system decline or failure. 

Here is likely an incomplete list of things that might be slowing showing up, softly, one by one as multi-system failure ramps up:

- anemia
- chronic dehydration
- increased resting heart rate
- breathing changes
- digestive troubles , bowel troubles (ie. runners diarrhea)
- endocrine problems: adrenal and hormonal shifts
- insomnia and sleeplessness
- blood pressure changes
- libido changes
- metabolism and appetite changes
- recurrent colds and viral infections
- generalized fatigue
- muscle soreness
- recurrent headaches
- inability to relax, listlessness
- swelling of lymph glands
- arrhythmias
- depression (neurotransmitter dysfunction)


There is a way out of OTS. But, one has to wrap their head around the fact that one's goals and mental drive have pushed them to this point. This is one's own fault and they will have to take some hard advice and make some tough decisions, decisions they do not want to make, but ultimately will have no choice but to make. That means changing those goals and habits, otherwise this could get real serious real fast. And wrapping one's head around the toughest part will be the most painful part for most, many months of rest, sometimes a year or more, to fully recover if one hasn't done too much irreparable damage to begin with.  Of course, the immediate course of action is to see a doctor. Hopefully, a doctor who is familiar with elite athletes and one that can rule out any other more serious immediate health concerns and disease processes that can mimic OTS and OR syndromes.

As with solving most problems, one has to first start to realize one is heading towards a problem, and accept responsibility. In this case, over training and under recovering.  One must look at their habits, and the subsequent outcomes, and see if there are signs of impending problems and if so be willing to make behavioral changes. This is a hard thing for endurance athletes, because it is asking them to look at enjoyable, admittedly addictive, endeavors. Endeavors that have always improved many facets of their life, yet ones that have a double edged-sword nature to them which can very quickly chop down all the hard work that has been put in. Ultimately, the answer is balance, balance in all aspects of one's life. But, who is truly good with balance ? Very few of us I am afraid.

Dr. Shawn Allen, one of the gait guys
 

References:

Running on Empty By: Meaghen Brown Jun 12, 2015.  Outside online. 
https://www.outsideonline.com/1986361/running-empty

Sports Health. 2012 Mar; 4(2): 128–138.Overtraining Syndrome. A Practical Guide
Jeffrey B. Kreher, MD†* and Jennifer B. Schwartz, MD‡
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3435910/

Med Sci Sports Exerc. 2013 Jan;45(1):186-205. Prevention, diagnosis, and treatment of the overtraining syndrome: joint consensus statement of the European College of Sport Science and the American College of Sports Medicine.
Meeusen R, Duclos M, Foster C, Fry A, Gleeson M, Nieman D, Raglin J, Rietjens G, Steinacker J, Urhausen A; European College of Sport Science; American College of Sports Medicine.

Open Access J Sports Med. 2016; 7: 115–122. Published online 2016 Sep 8.  Diagnosis and prevention of overtraining syndrome: an opinion on education strategies. Jeffrey B Kreher

Overtraining, Exercise, and Adrenal Insufficiency
KA Brooks, JG Carter
J Nov Physiother. Author manuscript; available in PMC 2013 May 9.
Published in final edited form as: J Nov Physiother. 2013 Feb 16; 3(125): 11717

Related citations:
https://scholar.google.com/scholar?ion=1&espv=2&bav=on.2,or.r_cp.&biw=1179&bih=705&dpr=1.5&um=1&ie=UTF-8&lr&cites=3025342060917260626

The glutes medius is playing target practice.

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We think about the gluteus medius often, mostly, during stance phases of locomotion. But, do not forget about the absolutely necessary function of the gluteus medius on the swing limb. Foot placement of that swing leg is in part dictated by how well the pendulum leg receives gluteus medius control to abduct the leg. When it fails to abduct adequately, a more adducted/medial foot placement occurs (think deeply about our long posts and podcast rants on the cross over gait, the narrow based walking and running gait style).
An agreeable balance between the abductors and adductors affords a more pure forward saggital pendulum of the hinging leg. When imbalanced, from insufficient gmedius and the rest of the abductory team, the foot and leg can target a more medial pendulum swing and thus a more medial foot target placement. Thus, the gluteus medius is important in both the stance and swing phases of gait. Failure to develop the skill, endurance and strength of the gluteus medius and related complex of muscles during stance AND swing phases will often result in frontal plane pelvis drift on the stance limb, and adduction targeting of the foot (narrow step width). What is this called ? We call it the Cross Over gait and we have written oodles of articles about this gait phenomenon, more than anyone else. It is real, it has economical advantages and similar liabilities. Want to learn more, type it into the SEARCH box on our website-blog. Many people thinkn this is a normal gait, how we should all walk and run. And they are wrong, in part. Like most things, it has a place, but not a permanent place. We think like most things in this world, there is a benefit and a drawback to things, and it is how you use it, as long as you read the instructions. Sadly, we were never given a "users manual" when we were born, so we all did what felt natural and safe. It doesn't mean it was right.


-Dr. Shawn Allen

For our Patreon patrons:
read and digest this post again before i film a video of a critical exercise we use to train the gluteus medius in BOTH PHASES ! All to often people just train the glute medius in the stance phase, and that is critical, but the swing phase is just as critical ! And this exercise i will film and post up on Patreon in the next 24 hours or so will help with this swing phase, but stance phase too. Be sure, when you study the video, that you do not get bogged down in what the exercise looks like. That is the easy part. For you to train yourself and your client, there MUST be a deep understanding of the specifics of the exercise. You have likely seen versions of this exercise other places, but it is the how and the why, and not getting sloppy with it, that is the key factor.

Photo: this came in an old box of Altra shoes, a brochure. We love Altras, they aren't for everyone, but if you are looking for a lower heel drop shoes with a wide toe box, try out a pair !

Holy Forefoot Flare, Batman!


Some sources say foot strike pattern does not matter. We disagree.

Look at this gal who midfoot/forefoot strikes. She also has a forefoot supinatus, a plastic condition where the forefoot is inverted with respect to the rearfoot. Take that combination and put it in a shoe with a forefoot flare and what do you get? Can you say AMPLIFICATION?

We’re not saying this is a bad shoe or even the wrong shoe. But, if she is going to run in this shoe, we will need to help her gain more ROM in her forefoot ( and some pelvic and hip stability) dodge doesn’t have to crash into eversion on each landing.

Help your patients with shoe selection. Something with less of a lateral flare in the forefoot would certainly make her life easier.

Need to know more? Consider taking our National Shoe Fit Program: link here:

Dr Ivo Waerlop, one of The Gait Guys

#badshoes #forefootflare #thegaitguys #forefootsupinatus #lateralflare #inversion

Metatarsalgia happens...

So a patient presents with forefoot pain, worse in the am upon awakening, with 1st weight bearing that would improve somewhat during the day, but would again get worse toward the end of the day and with increased activity. It began insidiously a few months ago (like so many problems do) and is getting progressively worse. Rest, ice and ibuprofen can offer some relief. You may see a dropped metatarsal head and puffiness and prominence in that area on the plantar surface of the foot, maybe not. Maybe you do a diagnostic ultrasound and see a lesion of the plantar plate as well? How did it get there? 

image courtesy of Tom Michaud: with permission

image courtesy of Tom Michaud: with permission

Lets look at the anatomy of the short flexors of the foot, as well as some biomechanics of the foot, ankle and hip. 

The flexor digitorum brevis (FDB) is innervated by the medial plantar nerve and arises from the medial aspect of the calcaneal tuberosity, the plantar aponeurosis (ie: plantar fascia) and the areas bewteen the plantar muscles. It travels distally, splitting at the metatarsal phalangeal articulation (this allows the long flexors to travel forward and insert on the distal phalanges); the ends come together to divide yet another time and each of the 2 portions of that tendon insert onto the middle of the middle phalanyx (1) 

As a result, in conjunction with the lumbricals, the FDB is a flexor of the metatarsophalangeal and proximal interphalangeal joints. In addition, it moves the axis of rotation of the metatasophalangeal joints dorsally, to counter act the function of the long flexors, which, when tight or overactive, have a tendency to drive this articulation anteriorly .Do you see any subtle extension of the metatarsophalangeal joint and flexion of the proximal interphalangeal joints on your exam?

We know that the FDB contracts faster than the other intrinsic muscles (2), playing a role in postural stability (3) and that the flexors temporally should contract earlier than the extensors (4), assumedly to move this joint axis posteriorly and allow proper joint centration. When this DOES NOT occur, the metatarsal heads are driven into the ground, causing irritation and pain.

If there is also a loss of ankle rocker this problem is made (much) worse. Why? Because, with the loss of one rocker, another must make up for the loss: ankle rocker decreases, forefoot rocker has to increase; this equals increased metatarsal head pressure. 

If you have been with us for any length of time, you know that ankle rocker and hip extension are intimately related, as one should equal the other, something we call “The “Z” angle”, that you have probably (hopefully?) read about here before. 

So what is the fix? Getting the FDB back on line for one. 

  • How about the toe waving exercise? 

  • How about the lift spread reach exercise? 

  • How about retraining ankle rocker and improving hip extension?

  • How about an orthotic with a metatarsal pad in the short term? 

  • How about some inflammation reducing modalities, like acupuncture, ice laser and pulsed ultrasound. 

  • Maybe some herbal or enzymatic anti inflammatories?



Dr Ivo Waerlop, one of The Gait Guys.

#gait #footpain #metatarsalgia #metatarsalpain #anklerocker #hipextension #thegaitguys



1. http://en.wikipedia.org/wiki/Flexor_digitorum_brevis_muscle

2. Tosovic D1, Ghebremedhin E, Glen C, Gorelick M, Mark Brown J.The architecture and contraction time of intrinsic foot muscles.J Electromyogr Kinesiol. 2012 Dec;22(6):930-8. doi: 10.1016/j.jelekin.2012.05.002. Epub 2012 Jun 27

3.Okai LA1, Kohn AF. Quantifying the Contributions of a Flexor Digitorum Brevis Muscle on Postural Stability.Motor Control. 2014 Jul 15. [Epub ahead of print]

4. Zelik KE1, La Scaleia V, Ivanenko YP, Lacquaniti F.Coordination of intrinsic and extrinsic foot muscles during walking.Eur J Appl Physiol. 2014 Nov 25. [Epub ahead of print]



Hallux amputation. What would you expect to present in this case ?

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The stuff we get/see.
Hallux amputation.
What would you expect to present in this case ?
We will dive into this one next week, but here are some cursory things to consider:

It is the right foot.
-Without the hallux, we cannot wind up the windlass and shorten the distance between the first metatarsal and heel, thus the arch will splay (more permanently over time we suspect) and we cannot optimize the arch height.
This will promote more internal spin on that limb because of more midfoot pronation and poor medial foot tripod stabilization.
- more internal limb spin means more internal hip spin, and more demand (which might not be met at the glute level) and thus loads that are supposed to be buffered with hip stabilization, will be transferred into the low back, and or into the medial knee. Look for more quad protective tone if they cannot get it from the glutes. Troubles arise when we try to control the hip from quadriceps strategies, it is poorly postured to do so, but people do it everyday, *hint: most cyclists and distance runners to a large degree)
- anterior pelvis posturing on the right, perhaps challenging durability of the lower abdominals, hence suspect QL increased protective tone, possible low back tightness or pain depending on duration of activities
- there is so much more, we are just wetting your appetite here on this one.
see you next week on this one gang !

Ivo and i are in the studio for another podcast this afternoon, hope you got to #137 this week ! lots more goodies to come !

cheers, shawn and ivo

Photo permission by patient

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The muscle they named wrong?

Why would you name a muscle after its supposed function when its function is actually something totally different? Probably due to what made sense from how it looked, not by how it acted. Of course, we are talking about the abductor hallucis.

tumblr_nn1ca5fx0C1qhko2so1_r1_1280.jpg

Think about all the anatomy you have learned over the years. Think about all the taxonomy and how it was done: sometimes by thename of the discoverer and more often by its anatomical location. The abductor hallucis seems to be the latter. 

The abductor and adductor hallicus function from approximately midstance to pre swing (1-4) (toe off), applying equal and opposite rotational vectors of force (in an ideal world) of the proximal phalynx of the hallux. This should resolve into a purely compressive force (5). In a closed chain environment, the transverse head of the adductor hallicus should act to prevent “splay” of metatarsals, along with the lumbricals and interossei (6), providing stabilzation of the forefoot (7) and rearfoot (8) during preswing, while the oblique head serves to help maintain the medial longitudinal arch. 

The abductor hallicus is actually a misnomer, as it most cases it is not an abductor but rather a plantar flexor of the 1st ray, particularly the proximal hallux, (assisting the peroneus longus) and supinator about the oblique midtarsal joint axis (5).  In the majority of cases, there doesn’t appear to be a separate, distinct insertion of the adductor hallicus to the base of the proximal phalynx, but rather a conjoint insertion with the lateral head of the flexor hallicus bevis into the lateral sesamoid and base of the proximal phalynx (9-11), emphasizing more of its plantar flexion function and stabilizing actions, rather than abduction. 

In one EMG study of 20 people with valgus (12) they looked at activity of adductor and abductor hallucis, as well as flexor hallucis brevis and extensor hallucis longus. They found that the abductor hallucis had less activity than the adductor. No surprise here; think about reciprocal inhibition and increased activity of the adductor when the 1st ray cannot be anchoroed. They also found EMG amplitude greater in the abductor hallucis by nearly two fold in flexion. 

So, the abductor hallucis seems to be important in abduction but more important in flexion. Either way, it is a stance phase stabilizer that we are beginning to know a lot more about. As for the name? You decide...



Dr Ivo Waerlop, one of The Gait Guys



1. Basmajian JV, Deluca CJ . Muscle Alive. Their Functions Revealed by Electromyography Williams and Wilkins. Baltimore, MD 1985, 377

2. Root MC, Orien WP, Weed JH. Normal and Abnormal Function of the Foot. Clinical Biomechanics, Los Angeles, CA 1977

3. Mann RA. Biomechanics of Running. In Pack RP. d. Symposium on the foot and leg in running sports. Mosby. St Louis, MO 1982:26

4. Lyons K, Perry J, Gronley JK. Timing and relative intensity of the hip extensor and abductor muscle action during level and stair ambulation. Phys Ther 1983: 63: 1597-1605

5. Michaud T. Foot Orthoses and Other Forms of Conservative Foot Care. Newton MA 1993: 50-55

6. Fiolkowski P, Brunt D, Bishop et al. Intrinsic pedal musculature support of the medial longitudinal arch: an electromyography study. J Foot & Ankle Surg 42(6) 327-333, 2003

7. Travell JG, Simons DG. Myofascial Pain and Dysfunction: The Trigger Point Manual. Williams and Wilkins, Baltimore 1992; 529

8. Kalin PJ, Hirsch BE. The origin and function of the interosseous muscles of the foot. J Anat 152, 83-91; 1987

9. Owens S, Thordarson DB. The adductor hallucis revisited. Foot Ankle Int. 2001 Mar;22(3):186-91. Am J Phys Med Rehabil. 2003 May;82(5):345-9.

10. Brenner E.Insertion of the abductor hallucis muscle in feet with and without hallux valgus. Anat Rec. 1999 Mar;254(3):429-34.

11. Appel M, Gradinger R. [Morphology of the adductor hallux muscle and its significance for the surgical treatment of hallux valgus][Article in German] Orthop Ihre Grenzgeb. 1989 May-Jun;127(3):326-30.

12. Arinci I, Geng H, Erdem HR, Yorgancioglu ZR Muscle imbalance in hallux valgus: an electromyographic study. Am J Phys Med Rehabil. 2003 May;82(5):345-9.


#halluxvalgus #halluxabductovalgus #bunion #footmuscleactivity #gait #thegaitguys



Sometimes too much shoe is too much...

Minimalist. Maximalist. Neutral. Sometimes you need to earn your way into a shoe. After all, a shoe is supposed to direct and guide your foot to better (more optimal?) mechanics, not necessarily create more work for it. The literature seems to point to maximalist shoes changing lower extremity kinematics and increasing impact forces. The body needs to have the ability to “attenuate“ these impact forces, otherwise problems could potentially arise.

Take a good look at this gal. She is having a heck of a time trying to control what her mechanics are doing in this maximalist shoe. She demonstrates poor control of the foot, as well as the knee and hip.

By design, the shoe has a thicker outsole and forefoot flare (ie: The front of the shoe is wider at the sole than it is at the interface of the foot with it). This can create accelerated forefoot pronation as you see here with the medial aspect of the foot “slapping“ down on the ground. This creates a large valgus moment at the knee, which is further accentuated by her external tibial torsion, greater on the left. Also notice the pelvic dip on the left on the right foot hits the ground; less so on the right side when the left foot strikes. Looking up the chain and as a whole, you can see that this is poor control and could potentially contribute to at the mechanics at the ankle, knee and hip. Not sure if you can see it but she also has an increase in her lumbar lordosis, diminishing her ability to be able to use her abdominal core to help to stabilize.

If she were to continue to want to utilize the shoe, we would need to work on core strength, hip stability and most likely, forefoot motion (so that she can get her first ray complex to the ground at the first metatarsal phalangeal joint), before she “earns her way” into this shoe.

Dr Ivo Waerlop, one of The Gait Guys

Kulmala JP, Kosonen J, Nurminen J, Avela J.Running in highly cushioned shoes increases leg stiffness and amplifies impact loading. Sci Rep. 2018 Nov 30;8(1):17496. FREE FULL TEXT

Law MHC, Choi EMF, Law SHY, Chan SSC, Wong SMS, Ching ECK, Chan ZYS, Zhang JH, Lam GWK, Lau FOY, Cheung RTH. Effects of footwear midsole thickness on running biomechanics. J Sports Sci. 2019 May;37(9):1004-1010

Chan ZYS, Au IPH, Lau FOY, Ching ECK, Zhang JH, Cheung RTH. Does maximalist footwear lower impact loading during level ground and downhill running? Eur J Sport Sci. 2018 Sep;18(8):1083-1089.

Sinclair J, Richards J, Selfe J, Fau-Goodwin J, Shore H.The Influence of Minimalist and Maximalist Footwear on Patellofemoral Kinetics During Running.J Appl Biomech. 2016 Aug;32(4):359-64. 

Chambon N, Delattre N, Guéguen N, Berton E, Rao G. Is midsole thickness a key parameter for the running pattern? Gait Posture. 2014;40(1):58-63

#runnning #gait #biomechanics #maximalistshoes #midsolethickness #gaitanalysis #thegaitguys

Some more really subtle things...How sharp are YOUR eyes?

As I study this video more and more (yep, we just keep looking at things because we are that nerdy and that paranoid that we missed something) I saw at least 3 very subtle findings. 

Watch the video of this right handed physical therapist who had L knee reconstruction (MCL/ACL with hamstring allograft) a few (hundred) times and see what you come up with, then come back and read this. We lie to slow things down and even frame by frame it with the slow motion feature or space bar to stop it. As background to the clinical exam, he has limited hip and knee extension on the left, 4/5 weakness of the quadratus femoris. His popliteus tests strong and 5/5. He has right sided back pain with L sided knee pain at the joint line and just inferior and medial. the treadmill is at a 2% grade at 2 mph.

Notice how he has a pelvic drift to the right during stance phase on that side. Why do you think? Remember, he has had a left sided knee surgery that left him with limited knee extension on that side. This creates a functional short leg on that side (the left), so he needs to get the longer (right) leg around. We don’t always see lateral movement of the pelvis on the longer leg side, but our guess is he is trying to “shorten” the longer leg side; lateral translation in the coronal plane is one strategy to accomplish that.

Now look at the left side. Can you see the subtle hip hike to clear the right leg? How about the small amount of circumduction? Sometimes folks will employ more than one strategy to get around a long leg, but ususally one will predominate, but not in this case. 

Did you catch the abductory twist of the right heel? The longer leg side needs to go through a greater range of motion of ankle dorsiflexion which will store more potential energy in the tricep surae as well as long flexors of the toes, that energy needs to go somewhere!

Now think about step length. It will often be shortened on the shorter leg side. He still needs to move forward the same amount, so he uses the right arm to help propel his center of mass forward. Do you see the increased arm swing? 

And why does he abduct his right arm so much? Where is his center of mass at left foot strike? It is all the way to the right, because of the “short leg”, correct? How can you counterbalance that? Abducting the arm would certainly accomplish that. Why does it go across the body? It is no longer needed to be that lateral during stance phase on the right, but he still needs to use it to propel himself forward with the shortened step length we talked about before. 

Mental gymnastics, running through what runs through our minds and why things may appear the way that they do. A great lesson in knowing what is supposed to happen and when in the gait cycle



Dr Ivo Waerlop, one of The Gait Guys



#kneepain #lowbackpain #gaitanalysis #thegaitguys #visualgaitanalysis

Walking on all Four limbs. The quad walkers. Uner Tan syndrome.

I wrote a multipart series on Uner Tan Syndrome, the people who walk on all fours years ago. Recently there has been a video of a young lady walking and running on all 4 limbs, like some kind of cat or canine. It triggered me to put this article up again on the research and thoughts behind this quadruped gait in humans. It worth rewinding today. We have written and updated several of our, and Dr. Tan's, theories and thoughts on it from direct communication with Dr. Tan. You can search for all the parts under "uner tan" in the search box.

"From the viewpoint of dynamic systems theory, it was concluded there may not be a single factor that predetermines human quadrupedalism in Uner Tan syndrome, but that it may involve self-organization, brain plasticity, and rewiring, from the many decentralized and local interactions among neuronal, genetic, and environmental subsystems."

Full Blog post here:

https://www.thegaitguys.com/…/the-hand-walkers-the-family-t…

The hand walkers: The family that walks on all fours. Part 1

Quadrupedalism and its commentary on human gait. To understand your athlete, your patient, your client, whatever your profession, you need to have a good understanding of neurodevelopment. If your client has some functional movement pattern flaws it could be from a delayed or expedited neurodevelopmental window. Generalized training and rehab will not correct an early or late window issue; often your work must be more specific.

When we began our journey into our daily writings on “The Gait Guys blog” we had no idea of the never ending tangents our writing would take pertaining to gait, human movement and locomotion. It has become plainly obvious over time that this blog will likely exist as long as we choose to continue it.

In 2006 we saw a documentary documentary entitled The Family That Walks On All Fours LINK: https://www.youtube.com/watch?v=ef3eKj4Pivk&feature=youtu.be
. . . and the video clip is from the documentary. It was a fascinating documentary and with our backgrounds in neurology, neurobiology, neuroscience, biomechanics and orthopedics we had more questions than the documentary touched upon. The documentary opened up many thoughts of neuro-development since we all start with a quadrupedal gait. But there had to be more to it than just this aspect because people eventually move through that neurologic window of development into bipedial gait. This has been in the back of our minds for many years now. Today we will touch upon this family and their challenges in moving through life, today we talk about Uner Tan syndrome, Unertan syndrome or UTS.

The original story is about the Ulas family of nineteen from rural southern Turkey. Tan described five members as walking with a quadrupedal gait using their feet and the palms of their hands as seen in this video. The affected family members were also severely mentally retarded and displayed very primitive speech and communication. Since his initial discovery several other families from other remote Turkish villages have also been discovered. In all the affected individuals dynamic balance was impaired during upright walking, and they habitually chose walking on all four extremities. Tan proposed that these are symptoms of Uner Tan syndrome.

UTS is a syndrome proposed by the Turkish evolutionary biologist Uner Tan. Persons affected by this syndrome walk with a quadrupedal locomotion and are afflicted with primitive speech, habitual quadrupedalism, impaired intelligence. Tan postulated that this is a plausible example of “backward evolution”. MRI brain scans showed changes in cerebellar development which you should know after a year of our blog reading means that balance and motor programming might be thus impaired. PET scans showed a decreased glucose metabolic activity in the cerebellum, vermis and, to a lesser extent the cerebral cortex in the majority of the patients. All of the families assessed had consanguineous marriages in their lineage suggesting autosomal recessive transmission. The syndrome was genetically heterogeneous. Since the initial discoveries more cases have been found, and these exhibit facultative quadrupedal locomotion, and in one case, late childhood onset. It has been suggested that the human quadrupedalism may, at least, be a phenotypic example of reverse evolution.

Neurodevelopment of Children:

Children typically go through predictable windows of neurodevelopment. Within a set time frame they should move from supine to rolling over. Then from prone they should learn to press up into a push up type posturing which sets up the spine, core and lower limbs to initiate the leg movements for crawling. Once crawling ensues then eventual standing and cruising follow. In some children, it is rare yet still not neurodevelopmentally abnormal, they move into a “bear crawl” type of locomotion where weight is born on the hands and feet (just as in our video today of UTS). Sometimes this window comes before bipedalism and sometimes afterwards but it should remain a short lived window that is progressed through as bipedalism becomes more skilled.

In studying Uner Tan Syndrome, Nicholas Humphrey, John Skoyles, and Roger Keynes have argued that their gait is due to two rare phenomena coming together.

“First, instead of initially crawling as infants on their knees, they started off learning to move around with a “bear crawl” on their feet.Second, due to their congenital brain impairment, they found balancing on two legs difficult.Because of this, their motor development was channeled into turning their bear crawl into a substitute for bipedalism.”

According to Tan in Open Neurol, 2010

It has been suggested that the human quadrupedalism may, at least, be a phenotypic example of reverse evolution. From the viewpoint of dynamic systems theory, it was concluded there may not be a single factor that predetermines human quadrupedalism in Uner Tan syndrome, but that it may involve self-organization, brain plasticity, and rewiring, from the many decentralized and local interactions among neuronal, genetic, and environmental subsystems.

There is much more we want to talk about on this mysterious syndrome and the tangents and ideas that come from it. We will do so in the coming weeks as we return to this case. We will talk about other aspects of neurodevelopment which should be interesting to you all since most our readers either are having children, will have them, or are watching them move through these neurologic windows. And we know that some of our readers are in the fields of therapy and medicine so this should reignite some thoughts of old and new. In future posts we will talk about cross crawl patterning in the brain, bear crawling, the use of the extensor muscles in upright posture and gait as well as other aspects of neurodevelopment gone wrong. We are not even close to being done with this video and all of its tangents. In the weeks to come we hope you will remain interested and excited to read more about its deep implications into normal and abnormal human gait.

author: Dr. Shawn Allen, one of the gait guys

References:

Open Neurol J.

2010 Jul 16;4:78-89. Uner tan syndrome: history, clinical evaluations, genetics, and the dynamics of human quadrupedalism.

Tan U

.Department of Physiology, Çukurova University, Medical School, 01330 Adana, Turkey.

link: http://www.ncbi.nlm.nih.gov/pubmed/21258577


Humphrey, N., Keynes, R. & Skoyles, J. R. (2005).

“Hand-walkers: five siblings who never stood up”

(PDF).

Discussion Paper

. London, UK: Centre for Philosophy of Natural and Social Science.

http://informahealthcare.com/…/abs/10.1080/00207450701667857

http://informahealthcare.com/…/abs/10.1080/00207450500455330

http://www.ncbi.nlm.nih.gov/pubmed…

https://www.youtube.com/watch?v=ef3eKj4Pivk&feature=youtu.be

The Short Foot Exercise

Here it is, in all its glory...Our version of the short foot exercise. Love it or hate it, say it “doesn’t translate”, we find it a useful training tool for both the patient/client as well as the clinician. It awakens and creates awareness of the sometimes dormant muscles in the user and offers a window to monitor progression for them, as well as the observer.

Remember that the foot intrinsics are supposed to be active from midstance through terminal stance/pre swing. Having the person “walk with their toes up” to avoid overusing the long flexors is a cue that works well for us. This can be a useful adjunct to your other exercises on the road to better foot intrinsic function.


Dr Ivo Waerlop, one of The Gait Guys

Sulowska I, Mika A, Oleksy Ł, Stolarczyk A. The Influence of Plantar Short Foot Muscle Exercises on the Lower Extremity Muscle Strength and Power in Proximal Segments of the Kinematic Chain in Long-Distance Runners Biomed Res Int. 2019 Jan 2;2019:6947273. doi: 10.1155/2019/6947273. eCollection 2019

Okamura K, Kanai S, Hasegawa M, Otsuka A, Oki S. Effect of electromyographic biofeedback on learning the short foot exercise. J Back Musculoskelet Rehabil. 2019 Jan 4. doi: 10.3233/BMR-181155. [Epub ahead of print]

McKeon PO, Hertel J, Bramble D, et al. the foot core system: a new paradigm for understanding intrinsic foot muscle function Br J Sports Med March 2014 doi:10.1136/bjsports-2013- 092690

Dugan S, Bhat K: Biomechanics and Analysis of Running Gait Phys Med Rehabil Clin N Am 16 (2005) 603–621

Bahram J: Evaluation and Retraining of the Intrinsic Foot Muscles for Pain Syndromes Related to Abnormal Control of Pronation http://www.aptei.ca/wp-content/uploads/Intrinsic-Muscles-of-the-Foot-Retraining-Jan-29-05.pdf


#shortfootexercise #footexercises #footrehab #thegaitguys #gaitanalysis #gaitrehab #toesupwalking



https://vimeo.com/342800960

Podcast 148: A deep dive case study. Plus, Central and Peripheral fatigue explained

tag/key words: gait, gaitproblems, gaitanalysis, forefootrunning, forefootstrike, heelstrike, pronation, central fatigue, peripheral fatigue, fatigue, hip rotation, gait biomechanics, running

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Just Google "the gait guys podcast".

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

Our podcast is on iTunes and just about every other podcast harbor site, just google "the gait guys podcast", you will find us.

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

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

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

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

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

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

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

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

Holy twisted tibias Batman! What is going here in this R sided knee pain patient?

Screen Shot 2019-06-10 at 12.28.38 PM.png

In the 1st picture note this patient is in a neutral posture. Note how far externally rotated her right foot is compared to the left. Note that when you drop a plumbline down from the tibial tuberosity it does not pass-through or between the second and third metatarsals. Also note the incident left short leg

Screen Shot 2019-06-10 at 12.28.56 PM.png

In the next picture both of the patients legs are fully externally rotated. Note the large disparity from right to left. Because of the limited extra rotation of the right hip this patient most likely has femoral retro torsion. This means that the angle of her femoral head is at a greater than 12° angle. We would normally expect approximately 40° of external Rotation. 4 to 6° is requisite for normal gait and supination.

Screen Shot 2019-06-10 at 12.28.47 PM.png

In the next picture the patients knees are fully internally rotated you can see that she has an excessive amount of internal rotation on the right compare to left, confirming her femoral antetorsion.

Screen Shot 2019-06-10 at 12.28.38 PM.png

When this patient puts her feet straight (last picture), her knees point to the inside causing the patello femoral dysfunction right greater than left. No wonder she has right-sided knee pain!

Because of the degree of external tibial torsion (14 to 21° considered normal), activity modification is imperative. A foot leveling orthotic with a modified UCB, also inverting the orthotic is helpful to bring her foot somewhat more to the midline (the orthotic pushes the knee further outside the sagittal plane and the patient internally rotate the need to compensate, thus giving a better alignment).


a note on tibial torsion. As the fetus matures, The tibia then rotates externally, and most newborns have an average of 0- 4° of internal tibial torsion. At birth, there should be little to no torsion of the tibia; the proximal and distal portions of the bone have little angular difference (see above: top). Postnatally, the tibia should twist outward (externally) a total of 15 degrees until adult values are reached between ages 8 and 10 years of 23° of external tibial torsion (range, 0° to 40°).

Wow, cool stuff, eh? Dr Ivo Waerlop, one of The Gait Guys

#tibialtorsion #tibialversion #kneepain #thegaitguys #gaitanalysis

Whole-body coordination patterns may become partitioned in particular ways as a function of task requirements

Just some more thoughts for those who insist on coaching arm swing changes.

"Whole-body coordination patterns may become partitioned in particular ways as a function of task requirements.”

Toddlers actively reorganize their whole body coordination to maintain walking stability while carrying an object. Hsu WH1, Miranda DL2, Chistolini TL3, Goldfield EC4. Gait Posture. 2016 Oct;50:75-81

Today we seem to be going back to dual-tasking again, in this case utilizing the arms as balance assistance devices, amongst their other functions. However, we all know that walking with a hand in a pocket, or carrying something alters our ability to maximize their ballast-like function. Balanced walking involves freely swinging the limbs in pendullar motion. Changes in arm swing will change gait economy and efficiency. We have all run with a water bottle or bag/briefcase and know how that changes the symmetry and fluidity of our gait.

Today's research piece discusses toddlers and their function as they carry objects. "children immediately begin to carry objects as soon as they can walk. One possibility for this early skill development is that whole body coordination during walking may be re-organized into loosely coupled collections of body parts, allowing children to use their arms to perform one function, while the legs perform another. Therefore, this study examines: 1) how carrying an object affects the coordination of the arms and legs during walking, and 2) if carrying an object influences stride length and width." -Hsu et al.In this study of 10 toddlers with 3-12 months of walking experience were recruited to walk barefoot while carrying or not carrying a small toy. "Stride length, width, speed, and continuous relative phase (CRP) of the hips and of the shoulders were compared between carrying conditions. While both arms and legs demonstrated destabilization and stabilization throughout the gait cycle, the arms showed a reduction in intra-subject coordination variability in response to carrying an object. Carrying an object may modify the function of the arms from swinging for balance to maintaining hold of an object. The observed period-dependent changes of the inter-limb coordination of the hips and of the shoulders also support this interpretation. Overall, these findings support the view that whole-body coordination patterns may become partitioned in particular ways as a function of task requirements." -Hsu et al.

So once again we will say it, if you are coaching the arm swing YOU want, because you do not like what you see in your client, or if you think you are helping your client get more out of their body in terms of speed, power, efficiency or anything of the sort, know that there is a higher, smarter program running the show. And that program in the client’s CNS is smarter than you when it comes to what they need for whole-body coordination pattern generation.

Ode to the Popliteus

Remember the popliteus? To recap, it contracts at the initial contact phase of the walking gait cycle, to act as an accessory PCL (look HERE

https://www.thegaitguys.com/search?q=popliteus&f_collectionId=57d4982c91b18610c6ee3e0f

to read about that), then contracts eccentrically to slow the rate of internal rotation of the femur on the tibia until midstance, so as not to macerate the meniscus; It then contracts concentrically to accelerate the external rotation of the femur on the tibial plateau so it rotates faster then the tibia, to protect the meniscus as well. So, internal rotation of the femorotibial complex from initial contact to midstance and external rotation of the complex from midstance to preswing. Got it?

Now look at the video of this gal with L sided medial knee pain and past history of a left tibial plateau fracture in her youth. Do you see it? Hmmmm; doesn’t look like internal rotation does it? Don’t see it? Remember that the whole complex SHOULD be internally rotating until the swing phase leg passes the stance pase leg. See it now? Considering that the popliteus tested weak on the clinical exam, does this surprise you?

Agreed that there are many factors initiating internal rotation (and thus pronation) of the stance phase leg from initial contact to midstance, like plantar flexion, adduction and eversion of the talus, contraction of the lower leg anterior compartment muscles, eccentric contraction of the quads and hamstrings, just to name a few, can you see how (a least theoretically) one bad player can ruin the team?

Yes, popliteus rehab, along with abdominal core and foot core endurance exercises are in her future.

Dr Ivo Waerlop, one of The Gait Guys

#popliteus #kneepain #kneeproblem #thegaitguys #gaitanalysis

Arm swing, let the CNS drive the show

For those arm swing/pulsers/ COM and head over foot folks consider some more research below.
Let the CNS drive the show, it is what it is there for . . . The leg motor patterns are dominant, the arms are passive and "shape" and influence the leg swing as a balance and ballast effect. As we discuss in an upcoming podcast, to cross the arms in a pumping motion across the midline of the body means one has to have compromised scapular mechanics (mostly protraction) to afford that much humeral adduction. This means we are forcing thoracic rotation as well. This means we are reversing what we know is more true, that "arm motion is driven passively by rotation of the thorax (Pontzer et al., 2009), an idea which is supported by shoulder muscle EMG data" (and not thoracic rotation by arm swing). Why would we try to create more unnatural axial spin through the spine when we are actually trying to move forward in the sagittal plane? Why would we try to force more rotation through the spine when the function of the thoracopelvic canister (ie. the core) is to stabilize rotational /angluar momentum? Hmmmm, things to ponder.

"Previous modelling studies have clearly shown that motion of the arms effectively counterbalances the angular momentum of the lower extremities during running (Hamner & Delp, 2013; Hamner et al., 2010). It has further been suggested that arm motion is driven passively by rotation of the thorax (Pontzer et al., 2009), an idea which is supported by shoulder muscle EMG data, consistent with the shoulders as spring-like linkages (Ballesteros, Buchthal, & Rosenfalck, 1965). Our data are con- sistent with this idea, showing motion of the thorax to be in the opposite direction to that of the swinging leg. Pontzer et al. (2009) also suggested that motion of the thorax is driven passively by motion of the pelvis. However, our data shows that the thorax reaches its peak angular velocity earlier than the pelvis, indicating that thorax motion is not completely passively driven by pelvic movements."

-S.J. Preece et al. / Human Movement Science 45 (2016) 110–118