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

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

Our Websites:
www.thegaitguys.com
Find Exclusive content at: https://www.patreon.com/thegaitguys
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.

Where to find us, the podcast Links:

iTunes page:
https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138?mt=2

Google Play:
https://play.google.com/music/m/Icdfyphojzy3drj2tsxaxuadiue?t=The_Gait_Guys_Podcast

Direct download URL: http://traffic.libsyn.com/thegaitguys/pod_1488_-_61419final.mp3

Permalink URL: http://thegaitguys.libsyn.com/podcast-a-deep-dive-case-study-plus-central-and-peripheral-fatigue-explained

Libsyn Directory URL: http://directory.libsyn.com/episode/index/id/10151672

Early motor experiences.

The early locomotor experience , a free play spontaneous study
Once again, we learn from our mistakes, or we should at least.
This natural locomotion study suggests that better walkers spontaneously walk more and fall less.

"Twelve- to 19-month-olds averaged 2,368 steps and 17 falls per hour. Novice walkers traveled farther faster than expert crawlers, but had comparable fall rates, which suggests that increased efficiency without increased cost motivates expert crawlers to transition to walking. After walking onset, natural locomotion improved dramatically: Infants took more steps, traveled farther distances, and fell less. Walking was distributed in short bouts with variable paths--frequently too short or irregular to qualify as periodic gait. Nonetheless, measures of periodic gait and of natural locomotion were correlated, which indicates that better walkers spontaneously walk more and fall less. Immense amounts of time-distributed, variable practice constitute the natural practice regimen for learning to walk."

Psychol Sci. 2012;23(11):1387-94. doi: 10.1177/0956797612446346. Epub 2012 Oct 19.
How do you learn to walk? Thousands of steps and dozens of falls per day.
Adolph KE1, Cole WG, Komati M, Garciaguirre JS, Badaly D, Lingeman JM, Chan GL, Sotsky RB.

Arm swing during gait. An energetic cost of locomotion?

"Arm swing during gait has an important role in decreasing energetic cost of locomotion. Several pathologies
may lead to various abnormalities in arm movements during
walking. It may therefore be expected that pathological gait is
energetically more demanding, not only because of the pathology, but also because of affected arm movements."- Meyns et all.

The Gait Guys ponder:
Can forcing what we think is a "better" arm swing pattern in turn be considered generating locomotor pathology? After all, we very well may be forcing a change to that which we see, a visual which we do not like, which was already a fundamental compensation around another locomotor deficit. ???

The how and why of arm swing during human walking
Pieter Meyns a,1, Sjoerd M. Bruijn a,b,1, Jacques Duysens a,c
Gait & Posture 38 (2013) 555–562

Gait is all-encompassing.

Last week we did a presentation on some very classic, yet challenging, gait video case presentations. This slide was a big piece of our presentation.
We discussed that there are volitional and non-volitional movements that accompany the adequate and appropriate postural system control.
If you want to hurt your brain, read this paper.
But in a nutshell what this paper says is that we have a constant switching between steady state cortical neuron discharge and and non-steady state discharge. For example, when we are on a flat road, no obstacles ahead of us, nothing but boring open road, the system sort of runs on an automated program, making limb movements calculated off of a normal unchallenged baseline. But, if there are roots, rocks, curbs, bikes to dodge, puddles to hurdle etc, the volitional and postural systems must change their operation, and alter limb movements based off of those postural systems as we pay attention, and negotiate the obstacles. There is this delicate symphony occurring between automated posture, calculated posture, rhythmic limb movements. In other words, there are volitional, reactionary and anticipatory plans and adjustments occurring in the background at all times.
But, make no mistake, bad, faulty, inefficient motor patterns can become automated if injuries are left, if they are left partially rehabed, if we teach our clients faulty patterns by overloading them and forcing adaptive patterns to inappropriate load or fatigue. These modifications occur deep in the CNS, much in the premotor cortices, and take into account body schema (their correct or distorted perception of where they are, or their limbs are, in space). Build strength or endurance on an altered schema, one that might be present from an old injury, and one will build strength and endurance where one does not want them to go. Properly training clients, offering corrective exercise and the like is far deeper that just asking your client to load and get stronger, unless you wish to assume that their limitations and compensations are unimportant. This takes us right back to the asymmetry debate, which we know so many love to dive into. Asymmetry is the norm of course, just don't be the person creating more of it for your client.

"Adaptive gait control requires constant recalibration of walking pattern to navigate different terrains and environments. For example, motor cortical neurons do not exhibit altered discharge during steady-state locomotion, but altered discharge occurs when the experimental animal has to overcome obstacles. Loops from the motor cortical areas to the basal ganglia and the cerebellum may contribute to this purpose (ie, contribute to accurate and adaptive movement control that requires volition, cognition, attention, and prediction). In contrast, cortical processing seems unnecessary during the automatic execution of locomotion. Rather, high-level processing may occur in the systems between the basal ganglia, cerebellum, and brainstem in the absence of conscious awareness. - TAKAKUSAKI , Neurophysiology of Gait: From the Spinal Cord to the Frontal Lobe

Movement Disorders, Vol. 28, No. 11, 2013

How the CNS adapts. Exploratory testing of the ground.

Screen Shot 2018-02-16 at 8.33.03 AM.png

What is happening at the 150 meter mark in a 200m sprint when that glute starts to fatigue ? What is happening at the 12th mile in a half marathon when stabilzation around that knee starts to falter?
In this article below, the authors discuss postural adaptations to unilateral hip muscle fatigue. This study merely looks at the effects during standing, so imagine what happens during locomotion when things start to fatigue.

Anyone who has sprained an ankle or banged up a knee knows what it is like to have an automated limping gait. The CNS is trying to reduce and shorten the loading response (and time) on the affected limb. This scenario goes on for awhile, days, maybe weeks, until it becomes somewhat more automated.
We just saw a client in the office just yesterday who had a subtle limp from a foot fracture 6 months ago. I mentioned it in passing, "isn't it amazing that your CNS can still be generating that limping adaptive gait even after 6 months, even now that the pain is no longer present?" His response, "What ? I am still limping? No I'm not ! Am I? Really?" I showed him the video, he was shocked. Things get automated, the CNS adapts, and it often doesn't know when to let go of an adaptive pattern even when it is no longer warrented. It is amazing to think that the brain often cannot logically process the incoming data and revert back to the sensory-motor program that was engaged pre-injury. Amazingly, perhaps the brain still knows better, perhaps it knows that things might seem fine, but lurking beneath the surface the sensory receptors are still sending soft warning signs that things still are not kosher.
We say something like this often to our clients, "The CNS makes momentary adaptive choices, but it has no way of foreseeing the consequences of an adaptive measure which is necessary in the moment. It makes these choices based on perceived stability, necessary mobility, economy, and pain avoidance, most of the time. But, it has no way of seeing into the future to see whether its choices have ramifications, it just chooses what makes the most sense in that moment." This is one of the reasons why we get so cranky about people who offer training and corrective exercise queues to people without deep thought, examination, and consideration. There can be ramifications down the road, that, in the present, are unseen and unknown. For example, just because you are running faster because you altered or augmented a client's arm swing, doesn't mean that newly trained pattern, that might even have the positive performance outcomes, won't have consequences that need to be walked back in the future. This is one of the premises of our recent arguments with the HOF (Head over Foot) crowd, who explicitly convey they only care about the clock and a client's speed, not about their well being down the road. There is no free lunch, the piper always gets paid, but just because we are not there to see the payment, it doesn't mean the day of reckoning isn't coming. We have been playing this human mechanic game now collectively for about 50 years, we know the payback is real, we see it often, eventually the tab for that free lunch shows up.

In this article below, the authors discuss postural adaptations to unilateral hip muscle fatigue. We are again looking for that Piper, he wants to get paid, so what is the consequence to the fatigue ? This study merely looks at standing, so imagine what happens during locomotion when things start to fatigue.

"The purpose of the present experiment was designed to address this issue by assessing the effect of unilateral muscle fatigue induced on the hip's abductors of the dominant leg on bipedal standing."

"Results of the experimental group showed that unilateral muscle fatigue induced on the hip's abductors of the dominant leg had different effects on the plantar CoP displacements (1) under the non-fatigued and fatigued legs, yielding larger displacements under the non-fatigued leg only, and (2) in the anteroposterior and mediolateral axes, yielding larger displacements along the mediolateral axis only. These observations could not be accounted for by any asymmetrical distribution of the body weight on both legs which were similar for both pre- and post-fatigue conditions. The observed postural responses could be viewed as an adaptive process to cope with an unilateral alteration in the hip neuromuscular function induced by the fatiguing exercise for controlling bipedal stance. The increase in CoP displacements observed under the non-fatigued leg in the fatigue condition could reflect enhanced exploratory "testing of the ground" movements with sensors of the non-fatigued leg's feet, providing supplementary somatosensory inputs to the central nervous system to preserve/facilitate postural control in condition of altered neuromuscular function of the dominant leg's hip abductors induced by the fatiguing exercise." - Vuillerme et at, 2009

We have discussed arm swing many dozens of times over the 9 years of blogging research on the web. You can search our blog for "arm swing" and go down the deep rabbit hole we have dug if you wish to learn how arm swing is not only necessary, but highly adaptive ballasts to help maintain balance and effective and adaptive locomotion. They can be used for improving or changing locomotion of all types. They can be looked at as prime movers or passive followers of the higher order leg swing. They can be coached right and wrong. The have a huge impact on COM (center of mass) and COP (center of pressure). And as a tangential comment of the article above, when the adaptive postural responses of the body are activated from a given fatigue in the body, COM and COP must change and adapt to keep us upright in the gravitational plane. These COM and COP changes are exploratory postural compensations, of which altered arm swing is often one adaptive and assistive measure. In this articles discussions, these compensations provide supplemental somatosensory inputs to the central nervous system to "preserve/facilitate postural control in conditions of altered neuromuscular function" when fatigue sets in somewhere. Bringing this all full circle, changing someone's arm swing, because you do not like how it looks (ie asymmetry, cadence, direction, etc), is foolish. The brain is doing it, because it likely has to do it to help adapt to a problem elsewhere that is altering the brain's perception of a safe COP and COM. Your job is to find out why and correct it, not to teach them a new way, which is very likely a new compensation to their already employed adaptive compensation.
-Shawn Allen, the other gait guy

Postural adaptation to unilateral hip muscle fatigue during human bipedal standing. Vuillerme N1, Sporbert C, Pinsault N. Gait Posture. 2009 Jul;30(1):122-5. doi: 10.1016/j.gaitpost.2009.03.004. Epub 2009 Apr 28.

Childhood Long Bone Torsions: Neurodevelopmental Considerations

Key Tag words:  torsions, gait, long bone torsions, femoral torsion, tibial torsion, neuromotor, neuroscience, locomotion, DNS, ambulation, walking, running, gait analysis, infant gait, childhood gait, jiu jitsu, crossover gait, cross over, vestibular, Parkinson's disease

We hit some good topics today, from childhood torsional issues, fix or leave alone ? What to look for when first observing and examining your client's gait plus Balance and vestibular function in gait and bike riding, exercise and neurodegenerative disorders and diseases and even developing proper neuromotor patterns, and inhibiting improper ones.
Plus we hit a favorite topic, the cross over gait and Ivo hits some highlights on gating inhibitory pathways.


Links to find the podcast:

iTunes page: https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138?mt=2

Direct Download: http://traffic.libsyn.com/thegaitguys/pod_134_Final.mp3

Permalink URL: http://thegaitguys.libsyn.com/childhood-long-bone-torsions-neurodevelopmental-considerations

Libsyn URL: http://directory.libsyn.com/episode/index/id/6247612


Our Websites:
www.thegaitguys.com

summitchiroandrehab.com doctorallen.co 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.

Show Notes:

Arm swing and hip ranges.

Most folks think they know a sufficient amount about arm swing, but the truth speaks otherwise for many. Many know heaps about upper quarter biomechanics and how to assess and evaluate the joints of the upper quarter but they have no clue what to look for when it comes to the client using the limb in locomotion. What really happens during the complex arm motions during gait and various forms of locomotion in runners and throwing sports ?
"For the first time, we provide evidence that the spinal interneuronal networks linking the forelimbs and hind limbs are amenable to a rehabilitation training paradigm. Identification of this phenomenon provides a strong rationale for proceeding toward preclinical studies for determining whether training paradigms involving upper arm training in concert with lower extremity training can enhance locomotor recovery after neurological damage.” -Shah et at, Brain 2013 Nov

"Our results demonstrate that altered hip rotational range of motion, measured clinically, has a direct effect on the amount of external rotation torque and horizontal adduction range of motion of the shoulder during the throwing motion." -Laundner et al, (article below)

Want to dive deeply into arm swing ? Want to really know what you are doing and missing ? Goto our blog (thegaitguys.tumblr.com) and in the search box type "arm swing". You will find nothing short of dozens of articles we have written on the topic.

The relationship between clinically measured hip rotational motion and shoulder biomechanics during the pitching motion

Kevin Laudner, Regan Wong, Takashi Onuki, Robert Lynall, Keith Meister

http://www.jsams.org/article/S1440-2440(14)00137-6/abstract

Starting and stopping your gait. How we do it gracefully.

Can you imagine being unable to stop moving graciously? Imagine that every attempt to halt your walking or running was like smacking into a wall or stumbling to a halt ? Kind of like that amateur driver who uses no grace or finesse, every start is a stomp on the gas and every stop is a slamming on the brakes.  Or can you imaging suffering from FOG (freezing of gait) as in some Parkinson’s patients ?  
When we are healthy, we take locomotion for granted. When we are in pain, movement can become labored and challenging; when we have a neurologic disease to the locomotor centers, we can find it almost impossible.  On occasion, it can be the seemingly simplest of things that can cause the greatest of difficulties, for example, we take stopping for granted and we underestimate the complexity of initiating movement. It is one of those things in life, you do not know what you have until you lose it.  When was the last time you even thought about starting or stopping your movements ? It is so natural that the thought doesn’t even reach the surface of our conscious thought.  When was the last time you walked towards your kitchen sink to wash the dishes and you consciously thought, 

“ok, we are about 3 more steps from the sink, you had better slow down … . ok, 2 more steps … 1 more step, this is the last one … .  ok, that is it, you have arrived at the sink, both feet stop moving … . . initiate double stance support, 50% weight on both feet… . .  begin standing mode.”

There is a brainstem pathway specifically dedicated to control locomotor arrest. Activating this pathway stops locomotion, while inhibiting the pathway enables locomotion.

In the study below, researchers Julien Bouvier and Vittorio Caggiano together with Professor Ole Kiehn and colleagues studied how the complex brainstem neuronal circuits control locomotion in mice.  What they found was this, 

Neuronal populations in the Reticular Formation of the brain “constitute a major excitatory pathway to locomotor areas of the ventral spinal cord. Selective activation of these neurons (V2a) of the rostral medulla stops ongoing locomotor activity, owing to an inhibition of premotor locomotor networks in the spinal cord. Moreover, inactivation of such neurons decreases spontaneous stopping in vivo. Therefore, the V2a “stop neurons” represent a glutamatergic descending pathway that favors immobility and may thus help control the episodic nature of locomotion.”-Bouvier et al.

Human locomotion is an extremely complex task. It is one that requires all sensory and motor pathways to be intact and reflexive controls such as central pattern generators to function properly.  Gait is a complex task that requires synchrony, rhythmicity, balance, coordination, endurance and strength to name a few.  Initiating gait is highly complex, as is arresting one’s gait.  We take for granted how complex these task are at coordinating muscles, joints, limbs, vision, proprioception, vestibular inputs and many other components not to forget the cerebral connection bring it all together to get us from one place to the next is a safe fashion. It is only when things go wrong that we realize how fragile, and how complex, the system truly is.  Don’t believe us ?  Well then, try to over ride the system next time you are coming to a curb at the corner of the busiest street in your town.  Try to over ride the coordinated stop mechanism that enables you to suddenly stop perched on the curb, observing oncoming traffic, standing safely without falling into the lane.

Shawn Allen, one of The Gait Guys

“Descending command neurons in the brainstem that halt locomotion” by Julien Bouvier, Vittorio Caggiano, Roberto Leiras, Vanessa Caldeira, Carmelo Bellardita, Kira Balueva, Andrea Fuchs, and Ole Kiehn in Cell. Published online November 19 2015 doi:10.1016/j.cell.2015.10.074

This brief blog post was inspired from this article on the same topic. http://neurosciencenews.com/v2a-neurons-locomotion-neuroscience-3119/

Trunk control in locomotion: What you may be realizing by now, if you have been with us here long enough, is that if you are getting good at the deepest of gait stuff, you are truly looking at your clients completely.  You are considering vision, vestibular, cerebellar, postural patterns, sensory and motor aspects, movement patterns, proprioception, coordination, S.E.S., stability, mobility, compensation patterns, dual tasking abilities and so much more.  We are working on new presentations and projects, soon for your eyes. Here is a slide from a new presentation to wet your whistle.

Trunk control in locomotion:
What you may be realizing by now, if you have been with us here long enough, is that if you are getting good at the deepest of gait stuff, you are truly looking at your clients completely.
You are considering vision, vestibular, cerebellar, postural patterns, sensory and motor aspects, movement patterns, proprioception, coordination, S.E.S., stability, mobility, compensation patterns, dual tasking abilities and so much more.
We are working on new presentations and projects, soon for your eyes. Here is a slide from a new presentation to wet your whistle.

Quadrupedal gait and tree climbing

Earlier today we posted on quadrupedal perspectives in locomotion. Now we find this to drive home the point.
A University of North Florida study “focused on "proprioceptively dynamic activities,” that is, ones that involved proprioception and a second factor (like locomotion or navigation) at the same time" such as climbing trees.
“All participants had their working memory tested at the start and two hours later (after climbing trees, running barefoot, and walking on a balance beam) and the researchers found that while the control groups showed no change, those who completed the proprioceptively dynamic tasks had a 50% jump in their working memory capacity.”

http://www.newser.com/story/210569/study-climbing-a-tree-is-good-for-your-brain.html