Neuro-adaptation, motor skills and strength. Does it come

We have discussed on recent podcasts about the concept of neuro-adaptation.
Neuro-adaptation is the initial strength gains we see in the first few weeks of corrective exercise homework, often it is more so better "coordination" of the motor patterns taught, and less so brute strength. But, it applies to strength training as well.

This strength increase is usually attributed to changes in the neural drive to muscle as a result of adaptations at the cortical or spinal level. This study investigated the change in the discharge characteristics of large populations of longitudinally tracked motor units in tibialis anterior before and after 4 weeks of strength training the ankle‐dorsiflexor muscles with isometric contractions. “

"We show for the first time that the discharge characteristics of motor units in the tibialis anterior muscle tracked across the intervention are changed by 4 weeks of strength training with isometric voluntary contractions.”
”The specific adaptations included significant increases in motor unit discharge rate, decreases in the recruitment‐threshold force of motor units and a similar input–output gain of the motor neurons.
The findings suggest that the adaptations in motor unit function may be attributable to changes in synaptic input to the motor neuron pool or to adaptations in intrinsic motor neuron properties." -Alessandro Del Vecchio et al

“These results demonstrate for the first time that the increase in muscle force after 4 weeks of strength training is the result of an increase in motor neuron output from the spinal cord to the muscle. “

The increase in muscle force after 4 weeks of strength training is mediated by adaptations in motor unit recruitment and rate coding
Alessandro Del Vecchio et al
Journal of physiology 06 February 2019

https://doi.org/10.1113/JP277250

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.

Nose picking and your running form problems.

Nose picking and running form

I use an example, with the appropriate clients, that humidifying one's home in the dry winter to try and break a nose picking behavior that was borne of resultant dry mucous linings doesn't necessarily mean one will break the 3 month habit of nose picking.
Furthermore, just because you decide to humidify the house doesn't mean your brain is going to halt the nose picking that has become a subconscious habit. Similarly, consciously asking someone to turn in their externally rotated foot (increased foot progression angle) or turn in the entire limb during gait, which might have been the result of frontal plane weakness of the ankle from an ankle sprain, isn't going to fix a problem that has now become an adaptive compensatory behavior at the hip. One has to get to the root of the problem, the unaddressed ankle sprain and neurologic behavioral adaptive patterns, at both the ankle and the hip. Plus, it just might get you to stop picking your beak, although, some sources now say that a good digested booger might be good for your immune system (probably a piece written by a happy confident picker).
- a Monday morning Dr. Allen rant

Cortical Remapping and Injuries (Redux)

"The gist of this article is that cortical remapping occurs with injuries that are not 100% resolved." - from our archives

Facilitating muscles, "activating" muscles, it is a 2 way street. There is the input into the brain and a corresponding motor output. If you are just "rubbing" out some muscles and get a stronger muscle test afterwards, and that is as far as your thoughts go before you turn your athlete loose, then you may be considered by some to be a stick in the spokes of the bigger system. Simple facilitation without corrective measures or corrective exercises to more permanently remap the optimal pattern may lead to repeated and recurrent pain, problems, re-injury or new injuries, and the like.

As a client adapts to their unresolved, partially resolved (yes, even 95% is unresolved) injury(s) a secondary cascade of neurological changes ensue that often force new cortical remapping. A remapping that is not as fundamentally safe or as sound as the pre-injury mapping yet one that is necessary for protecting further or other injuries. Yet, because it is not the original pristine pattern, it is also one that can begin undercurrents to corrupt other patterns of stability, mobility and movement in cortical and subcortical mappings. Understanding cortical excitability is important, and it can work for you and your client or against you both. It can be used for good or evil.

read on here . . . .

https://thegaitguys.tumblr.com/post/80788172925/activation-cortical-remapping-and-what-you-are

Activation, Cortical Remapping and what you are doing wrong to your people.

We are getting ready to step back into the studio to record podcast 58. We have been touching upon this topic off and on in the last 2 podcasts and we are going back in for more on pod #58 because this stuff is just too important not to beat it to a further pulp.  

The gist of this article is that cortical remapping occurs with injuries that are not 100% resolved. Lots of coaches and trainers out there are trying their hands at muscle “activation” and other new trendy tricks and they are missing the boat and making people worse if they are not doing a good sound clinical history and examination. You can activate any muscles and get what appears to be a miracle response, we can teach a 8 year old how to do activation and get a miracle response, but is it the right response or have you created a temporary compensation for your client (right before you send them into training or competition) ?  Activation is a 2 way street, there is the input into the brain and a corresponding motor output. If you are just rubbing out some muscles and get a stronger muscle test afterwards, and that is as far as your thoughts go before you turn your athlete loose, then you are a liability in the system. Are you part of the problem or part of the solution ?

Here are 2 paragraphs from this brilliant article. This is worth your time. As a client adapts to their unresolved, partially resolved (yes, even 95% is unresolved) injury(s) a secondary cascade of neurological changes ensue that often force new cortical remapping.  A remapping that is not as fundamentally safe or as sound as the pre-injury mapping yet one that is necessary for protecting further or other injuries. Yet, because it is not the original pristine pattern, it is also one that can begin undercurrents to corrupt other patterns of stability, mobility and movement in cortical and subcortical mappings. Understanding cortical excitability is important, and it can work for you and your client or against you both. It can be used for good or evil.  

If after you read these 2 paragraphs taken from the Alan Needle article in LER (link) you think you might be part of the problem or realize that you are not the magician you think you are, then good, you are on the track to self enlightenment and actually helping people.  Go read Alan’s article and breathe deep, ready to absorb and start yourself into understanding that you are really fixing the brain and not always the muscle, and that means you are gonna have to learn about the brain and how it works and more so how it can deceive you and your client and your training, treatments or therapy.

Come join us on The Gait Guys podcast 58 later this week as we delve into this topic deeper and more broadly.

Shawn and Ivo

PS: nice article Dr. Needle. Thank you !

http://lowerextremityreview.com/article/the-brain-a-new-frontier-in-ankle-instability-research

The brain: A new frontier in ankle instability research

http://lowerextremityreview.com/article/the-brain-a-new-frontier-in-ankle-instability-research\

“Recently Wikstrom and Brown proposed a hypothetical cascade of events that would affect an individual’s ability to “cope” following an ankle sprain and provide a rationale for the varying contributors to instability. For an individual starting from a point of normal function, a lateral ankle sprain will trigger a consistent pattern of changes to the joint from the inflammatory process. Swelling will increase pressure on the joint’s mechanoreceptors, and pain will contribute to inhibition of the reflexes to the joint (arthrogenic inhibition). Together, this means patients will have difficulty sensing the joint and subsequently stabilizing it while excessive mechanical laxity will increase this loss of stability.19

Inflammatory changes may be similar across all patients; however, as symptoms remain and the patient adapts after his or her injury, a secondary cascade of neurological changes may occur that may include cortical remapping. In some patients, these adaptations may be beneficial and serve to protect the joint from further injury. Other patients may maladapt, as sensorimotor reorganization changes the nervous system’s perception of the joint. Variable amounts of laxity, proprioception, and cortical excitability exist throughout populations of healthy, previously injured, and functionally unstable joints. Where these populations diverge may be related to how each is scaled relative to the others. For instance, a joint with greater amounts of laxity may have higher proprioception and excitability to aid in stabilizing the joint, but following injury, these factors may become decoupled, leading to errors in movement and coordination.19”  -Alan Needle, PhD

Central Pattern Generators (CPGs) and gait / locomotion. Do the arms and legs talk to eachother ?

On the topic of central pattern generators (CPGs) and gait / locomotion

"If quadrupedal coordination is deeply embedded in the human nervous system then one might expect this to be revealed in conditions when there is a conflict between voluntary arm movements and walking. For example, Muzii et al. [44] combined a walking and a clapping task at preferred rates. Hand clapping was found to be tightly coupled to heel strike. When instructed to walk and clap at different rates (e.g. walk normally but clap faster) the subjects were not able to perform this task, implying that the walking rhythm dominated the coordination. Hence coupling is fairly robust, a finding that was confirmed by the observation that the typical 1:1 diagonal coordination during gait is maintained even when either one of the limbs involved is loaded with an extra 2 kg." - P. Meyns et al. / Gait & Posture 38 (2013) 555–562

We have discussed this same thing during our "dual tasking" blog posts. These things can be learned and modified with attentive training, but is it strongly suggested that the underlying CPG patterns are fairly robust.  This is not to say that leg swing is the king, that it runs the show, but it seems dominant. And as the Meyns paper reviews, there is an influence from the upper limbs in terms of enhancing and shaping the overall movement and coordination of all 4 limbs.

And as the Meyns paper states, "although the connections go both ways, it is clear in the to date animal models studied, that "the caudorostral connections seem to be the most powerful ones." Meaning, the pelvis and lower limb motor patterns and pattern generators seem to dominate over the upper limbs and upper pattern generator centers.
"The dominance of the lumbosacral girdle over the cervicothoracic is probably preserved in humans as well. For example, Sakamoto et al. [65] showed that during combined arm and leg cycling, the cadence of the arms was significantly altered when leg cycling cadence was changed. The opposite, however, was not true, i.e. the arms did not affect the leg cadence." Meyns et al.

And, "the authors concluded that ‘‘the neural signal induced by the upper limb movements contributes not merely to enhance, but to shape the lower limb locomotive motor output, possibly through interlimb neural pathways’’.-Myens et al.

The how and why of arm swing during human walking
Pieter Meyns a,1, Sjoerd M. Bruijn a,b,1, Jacques Duysens a,c,*
P. Meyns et al. / 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

Podcast 108: Calf Muscle Power & Motor Signatures.

Running, gait, human sociomotor interactions and the power of behavioral plasticity.

A. Podcast links:

http://traffic.libsyn.com/thegaitguys/pod_108f.mp3

http://thegaitguys.libsyn.com/podcast-108-motor-signatures-motor-learning-calf-power

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

C. Gait Guys online /download store (National Shoe Fit Certification & more !)
http://store.payloadz.com/results/results.aspx?m=80204

D. other web based Gait Guys lectures:
Monthly lectures at : www.onlinece.com type in Dr. Waerlop or Dr. Allen, ”Biomechanics”

-Our Book: Pedographs and Gait Analysis and Clinical Case Studies
Electronic copies available here:

-Amazon/Kindle:
http://www.amazon.com/Pedographs-Gait-Analysis-Clinical-Studies-ebook/dp/B00AC18M3E

-Barnes and Noble / Nook Reader:
http://www.barnesandnoble.com/w/pedographs-and-gait-analysis-ivo-waerlop-and-shawn-allen/1112754833?ean=9781466953895

https://itunes.apple.com/us/book/pedographs-and-gait-analysis/id554516085?mt=11

-Hardcopy available from our publisher:
http://bookstore.trafford.com/Products/SKU-000155825/Pedographs-and-Gait-Analysis.aspx

________________________

Show Notes:

The way you move gives clues.
http://neurosciencenews.com/movement-personality-traits-3907/

http://rsif.royalsocietypublishing.org/content/13/116/20151093

Biomechanics of Propulsion
http://lermagazine.com/cover_story/biomechanics-of-propulsion-implications-for-afos

Altered plantar pressures
http://link.springer.com/article/10.1007%2Fs00167-016-4015-3

Gait and Climbing (and DNS): Part 2.  Introducing 14 year old Ashima Shiraishi.

14 year old “sends” V15 , a 30 move roof climb in Hiei, Japan, called “Horizon”.

“the present work showed that human QL (quadrupedal locomotion) may spontaneously occur in humans with an unimpaired brain, probably using the ancestral locomotor networks for the diagonal sequence preserved for about the last 400 million years.” - 2005 Shapiro and Raichien

I am flipping the script a little today for DNS’ers (Dynamic Neuromuscular Stabilization). Watch the video if you wish, but the point I will be drawing your attention to is the 2:15 mark when she goes inverted on the roof of this apparently “more simple” V9 route. Note, this is not a video of her historic ~30 move V15 route. Stay tuned for that, it is not available yet.

Look closely. In the video, a then 9 year old Ashima is climbing upside down, a roof climb, defying gravity’s push. Spin this picture 180 and she is crawling, finding points of “fixation” or “punctum fixum”. What is neat about climbing is that you can have one, two, three or four points of fixation, unlike walking (one or two points) and crawling (two, three or four points of fixation). The difference in climbing is that gravity is a bear, wearing you down, little by little. A deep similarity in climbing to any variety of crawling is that both involve pulling and pushing, compressing and extending over fixation points. Other common principles are those of fixation, stability, mobility and neurologic crawling patterns in order to progress.

Ashima just recently, in early 2016, was the first female to complete a V14d (it is said it may even be upgraded to a V15a, maybe even a V16). Not many pros of any gender can say they can complete a V15 so this is a real big deal for a 14 year old. Stay tuned for that video.

DNS, Kolar and Climbing

I took my first DNS course with Prof. Kolar 10 years ago. It was an interesting eye opener and I had just enough clinical experience (9 years at that point) to grasp just enough to take it back to my practice and integrate it. Since that time, it has been fun to see it grow and see young practitioners excited to get their first face palm epiphanies. I have been returning to it often, blending it into my rehab work much of the time. There are few hip, shoulder, spine, breathing or global stabilization exercises I prescribe that do not have a DNS component to them, with my own flare and alterations and amendments as necessary. If you have taken a DNS course you will know why I am bring the topic into climbing. If you have not taking a course, you will be a little lost on the conceptual spill over.

As you can see in the video above, start really paying attention at the 2:15 mark in the video when she goes inverted on the roof. Cross crawl patterns, concepts of fixation, compression, expansion, crossing over, and tremendous feats of shoulder and hip stability on spinal stiffness and rotation.  Now add breathing, oy !  Now add doing all of this by mere finger tip and toe tip fixation ! When you consider all of this, it becomes almost incomprehensible what she and other climbers are doing when they go inverted like this. Amazing stuff, finger pulling/compression and foot pushing to compressively attach the body to the wall and progress forward.

Lucid Dreaming, A climb in the Buttermilks

Last year I wrote a piece on Lucid Dreaming, the name of a rock (another V15 climb) in the Buttermilks of Bishop, California. Here is that blog post. Lucid Dreaming is no ordinary rock.  To summit this rock is basically only three moves off of three holds, from your fingertips, starting from a sitting position. The remainder of the climb is sliced bread. If you can do the three, you can get to the top. The problem is, only a handful of people in the world can accomplish the feat. In the piece I outlined many principles of crawling, quadruped and climbing from a neuro-biomechanical perspective. Here is a excerpt from what i wrote in Gait and Climbing, Part 1:

In climbing there is suspicion of a shift in the central pattern generators because of the extraordinary demand by pseudo-quadrupedal gait climbing due to the demand on the upper limbs and their motorneuron pools to mobilize the organism up the mountain.  We know these quadrupedal circuits exist. In 2005 Shapiro and Raichien wrote “the present work showed that human QL (quadrupedal locomotion) may spontaneously occur in humans with an unimpaired brain, probably using the ancestral locomotor networks for the diagonal sequence preserved for about the last 400 million years.”

Some research has determined that in quadrupeds the lower limbs displayed reduced orientation yet increased ranges of kinematic coordination in alternative patterns such as diagonal and lateral coordination.  This was clearly different to the typical kinematics that are employed in upright bipedal locomotion. Furthermore, in skilled mountain climbers, these lateral and diagonal patterns are clearly more developed than in study controls largely due to repeated challenges and subsequent adaptive changes to these lateral and diagonal patterns.  What this seems to suggest is that there is a different demand and tax on the CPG’s and cord mediated neuromechanics moving from bipedal to quadrupedal locomotion. There seemed to be both advantages and disadvantages to both locomotion styles. Moving towards a more upright bipedal style of locomotion shows an increase in the lower spine (sacral motor pool) activity because of the increased and different demands on the musculature however at the potential cost to losing some of the skills and advantages of the lateral and diagonal quadrupedal skills. Naturally, different CPG reorganization is necessary moving towards bipedalism because of these different weight bearing demands on the lower limbs but also due to the change from weight bearing upper limbs to more mobile upper limbs free to not only optimize the speed of bipedalism but also to enable the function of carrying objects during locomotion.

The take home seems to suggest the development of proper early crawling and progressive quadruped locomotor patterns. Both will tax different motor pools within the spine and thus different central pattern generators (CPG). A orchestration of both seems to possibly offer the highest rewards and thus not only should crawling be a part of rehab and training but so should forward, lateral and diagonal pattern quadrupedal movements, on varying inclines for optimal benefits. 

Dancing, Jiu Jitsu and Climbing. Bringing things together.

So, what am I doing with all this information? As some of you may know, I have been expanding my locomotion experiences over the years. First there was three years of ballroom and latin dance, some of the hardest stuff I have ever done, combining complex combined body movements to timing and music at different speeds, each time changing to different rhythms or genres of music. Some of my deepest insights into foot work and hip, pelvis and core stability and spinal mobility originated from my dance experiences, particularly Rumba, Cha Cha, Jive, Waltz and Foxtrot. On a side note, some of my greatest epiphanies about the true function of the peroneal-calf muscle complex came during a private session on a difficult Waltz step concept. It was such an epiphany I sat down and wrote scratch notes on the enlightenment for 20 minutes right there in the ballroom. Next I moved into the very complex martial art of Brazilian Jiu Jitsu, and after three years it is clear it is an art that you could do for a lifetime and never get to the end of the complex algorithms of defense and offense. This art will stay in my wheelhouse to the end if I am able to keep it there.

Rock climbing, this one is the next on the list. After years of sharing my hands on peoples physical problems I know I already have above average grip and finger strength, so this could either prove to be a blessing or a “career ender” in terms of finally finishing off my hands for good. But it is on the list, and it won’t leave my head, so for me that is the tipping point. Climbing is next. I need to understand and experience this, so I can understand human locomotion better.

I will have the video of Ashima “sending” V15+ when they put it up, stay tuned. I have a feeling it is going to be a jaw dropper, I hear the whole send is inverted which boggles my mind. We will dissect her roof crawling and I will try to have some new research for you.

If you want to come down my rabbit hole, come read some of my other related articles:

Part 1: Gait and Climbing. Lucid Dreaming

and my 3 part series on Uner Tan Syndrome. The people who walk on all fours.

Dr. Shawn Allen, one of the gait guys

___________

References:

Shapiro L. J., Raichien D. A. (2005). Lateral sequence walking in infant papio cynocephalus: implications for the evolution of diagonal sequence walking in primates. Am. J. Phys. Anthropol.126, 205–213 10.1002/ajpa.20049

Scand J Med Sci Sports. 2011 Oct;21(5):688-99. Idiosyncratic control of the center of mass in expert climbers. Zampagni ML , Brigadoi S, Schena F, Tosi P, Ivanenko YP

J Neurophysiol. 2012 Jan;107(1):114-25. Features of hand-foot crawling behavior in human adults. Maclellan MJ, Ivanenko YP, Cappellini G, Sylos Labini F, Lacquaniti F.

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

Quadruped facts.

Do the intimate relationships of the upper limbs and lower limbs suggest that quadrupedal skill sets, if not true quadrupedal gait, were a piece of our past locomotion strategies ? Or is it just representative of the close linkages for gait efficiency? Or maybe both?
Join us on the blog today for a short rewind piece where we discuss beaucoup things … . such as:
“this study’s results provide strong evidence that actively engaging the forelimbs improves hindlimb function and that one likely mechanism underlying these effects is the reorganization and re-engagement of rostrocaudal spinal interneuronal networks. ”

Here is the blog link:

http://thegaitguys.tumblr.com/post/111383241429/spinal-interneuronal-networks-linking-the

Muscle activity

Does variability in muscle activity reflect a preferred way of moving or just reflect what they’ve always done? In this study it was found that there isn’t always this tight relationship between activity in the muscles and the movement we’re seeing.
“Clearly, locomotion is not as simple as we thought it was,” Foster said. “This decoupling – big changes in movement without corresponding changes in muscle activity – suggests there are other important factors going on and we need to better understand them if we want to reproduce these movements in prosthetics or robotics.”
Hmmmm. thoughts. this makes everything more interesting doesn’t it ?!

http://esciencenews.com/articles/2014/03/14/motion.and.muscles.dont.always.work.lockstep.researchers.find.surprising.new.study

“Neural circuits linking activity in anatomically segregated populations of neurons in subcortical structures and the neocortex throughout the human brain regulate complex behaviors such as walking, talking, language comprehension, and other cognitive functions associated with frontal lobes.” 1

We also found this interesting quote from Science Daily on this topic of complex sensory motor behaviors and on the varying information on central pattern generators.

ScienceDaily (June 3, 2012) — “A new finding that motor cortex is a dynamic pattern generator upends existing theory with broad implications for neuroscience.”

“Maybe it is actually easier to understand than we thought. A new paper presents some compelling evidence that the motor cortex, rather than being command central, is more like a part of the machine, sending rhythmic signals down the spinal cord to orchestrate movement.”

"The electrical signal that drives a given movement is therefore an amalgam — a summation — of the rhythms of all the motor neurons firing at a given moment.” This is of course monitored (and modified) by one of our best friends, the cerebellum. 2

The cortex is where movement begins and where it ends; from areas 4, 4s and 6 in the precentral gyrus of the brain’s frontal lobe, down the spinal cord and out to the muscle through the peripheral nerve.   It is also where the information from the body’s receptors feed back,  to give updates on where the body parts are in space (proprioception) and how they are doing functionally (comparing information about length, tension, etc).  It is about sensory and motor function.  Motor function is based on sensory input.  Good motor function is based on good sensory information. It is a subtle, beautiful, intricate symphony.  And when one part goes wrong, the whole system can be thrown off.  

Here is an example we sometimes use in our lectures and with our patients to make this point clear.  Imagine an orchestra playing Beethoven’s beautiful Ode to Joy, a choral symphony for orchestra.  Now imagine one of the musicians begins to play off key. In time, the musicians sitting around that musician who are most locally influenced by that off tune musician, soon become irritated and have troubles playing “in tune”. In time, if not rectified, the whole orchestra could be corrupted and being to take that lead as well.  Hard to believe, but it makes the point that all it takes is one piece not playing well to change the outcome. Similar analogy, all it takes is one weak muscle or one painful joint and the outcome is skewed away from the optimal outcome and in time local dysfunction and compensation becomes an all encompassing compensation. The body’s function and operation, when proper, is an orchestra and orchestration with each piece doing a local job with a more global contribution to the bigger job. When all pieces come together appropriately it creates a symphony of flawless, effortless movement as seen in the video above.

Shawn and Ivo, the gait guys

refs:

1. Front Syst Neurosci. 2014 Feb 13;8:16. eCollection 2014. Cognitive motor interactions of the basal ganglia in development .  Leisman G1, Braun-Benjamin O2, Melillo R3.

"Postures must have integrity. Patterns must have economy."

We love Gray Cook’s memes.

“Postures must have integrity.  Patterns must have economy.”

This one is a keeper…….we would like to add that “patterns must have economy AND capacity”.

We have talked about central fatigue here on FB and our blog, and it has alluded to the fact that neuromuscular motor patterns are driven centrally from the CPG’s (central pattern generators in a few areas of the brain). Metabolic capacity problems can alter motor patterns, so fatigue can come centrally as well as peripherally at the muscle, which we typically think of when we think of fatigue. The brain has a metabolic demand as well, and if it hits a “fuel” limitation (cerebral hypometabolism) the movement driven from that path will be corrupt. Craig Liebenson refers to muscle “amnesia”, perhaps this is what he is alluding to, it is a central fuel capacity fatigue issue to be more precise. Here at The Gait Guys we like to say you better have S.E.S. (skill, endurance, strength). The endurance is a local and a central fuel endurance thing. Thanks Gray ! Move well, move often.

Shawn and Ivo

the gait guys

_______

“Human muscle fatigue does not simply reside in the muscle”.

So you like to “activate” clients muscles huh? Its the big flashy trend right now done by some folks who know very little about what they are doing and perhaps adding risk to athletes right before an event or practice.
How much do you really know what you are doing ?
Have you heard of “central fatigue” and the neural mechanisms underlying it? Do you think that merely “activating” your client will make them safe and perform better on the field ? What if it added even more risk to their system ? If you are only driving the changes at the end organ, the muscles and their receptors, you may not even be half way there. Read on … .

“Muscle fatigue is an exercise-induced reduction in maximal voluntary muscle force. It may arise not only because of peripheral changes at the level of the muscle, but also because the central nervous system fails to drive the motoneurons adequately. Much data suggest that voluntary activation of human motoneurons and muscle fibers is suboptimal and thus maximal voluntary force is commonly less than true maximal force. Hence, maximal voluntary strength can often be below true maximal muscle force. The technique of twitch interpolation has helped to reveal the changes in drive to motoneurons during fatigue. Voluntary activation usually diminishes during maximal voluntary isometric tasks, that is central fatigue develops, and motor unit firing rates decline.Transcranial magnetic stimulation over the motor cortex during fatiguing exercise has revealed focal changes in cortical excitability and inhibitability based on electromyographic (EMG) recordings, and a decline in supraspinal "drive” based on force recordings. Some of the changes in motor cortical behavior can be dissociated from the development of this “supraspinal” fatigue. Central changes also occur at a spinal level due to the altered input from muscle spindle, tendon organ, and group III and IV muscle afferents innervating the fatiguing muscle. Some intrinsic adaptive properties of the motoneurons help to minimize fatigue. A number of other central changes occur during fatigue and affect, for example, proprioception, tremor, and postural control. Human muscle fatigue does not simply reside in the muscle.“

Hopefully stuff like this ruffles some feathers, raises eyebrows and questions, starts deeper meaningful dialogues, forces people to understand their scope and pay grade, and forces us all to ask harder questions especially when things seems easy and too good to be true. There is no finger pointing here dear brethren, so no need to retaliate or raise up arms to defend a position. Just read the research and ask yourself the tough questions…… “am i part of the solution, or part of the problem”? We can all do better, lets all raise up and step up, and elevate the professions together. It can only make it better for those that need it, our clients and patients.

Physiol Rev. 2001 Oct;81(4):1725-89.
Spinal and supraspinal factors in human muscle fatigue.
Gandevia SC

Pod #22: Primates, Limb Synchrony & Motor Patterns

Pod #22: Primates, Limb Synchrony & Motor Patterns

blog link:

http://thegaitguys.libsyn.com/pod-22-primates-limb-synchrony-motor-patterns

iTunes link:

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

Show notes:

Neurscience piece:

New Study shows primates move in unison as well.

http://www.labspaces.net/126488/Primates_too_can_move_in_unison

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

The synchronization between walking partners is more complex than it seems on the surface.  There are two types of synchronization,:
1- in-phase (both person’s right foot move forward at the same time) and
2- out-of-phase synchronization (where the right foot moves forward with the partners left foot).

Ankle-Dorsiflexion Range of Motion and Landing Biomechanics
Chun-Man Fong, Athl Train. 2011 Jan-Feb; 46(1): 5–10.
What comes first ?  Muscle weakness,  Inhibition (muscle) or a Compensated movement pattern ?

An Alternate View of Crawling and Quadrupedal Motor Patterns: A Correlation to Free Solo Mountain Climbers ?

Quadruped Patterns: Part 1

In the last 3 years, if you have been with us here at The Gait Guys that long, you will have read some articles where we discuss quadrupedal gait (link: Uner Tan Syndrome) and also heard us talk about CPG’s (Central Pattern Generators) which are neural networks that produce rhythmic patterned outputs without sensory feedback. You will have also read many of our articles on arm swing and how they are coordinated with the legs and opposite limb in a strategic fashion during gait and running gaits. Through these articles, we have also eluded to some of the fruitless aspects of focusing solely on retraining arm swing in runners because of the deep neurologic interconnectedness to the lower limbs and to the CPG’s. 
IF you are interested in any of these articles we have written please feel free to visit our blog and type in the appropriate words (Uner Tan Syndrome, arm swing, cerebellum, cross over gait) into the Search box on the blog.

Here we briefly look at interconnected arm and leg function in crawling mechanics in a high functioning human (as compared to the Uner Tan Syndrome) in arguably the best solo free climber in the world, Alex Honnold. Here we will talk about the possible neurologic differences in climbers such as Alex as compared to other quadruped species. Primarily, there is suspect of an existing shift in the central pattern generators because of the extraordinary demand on pseudo-quadrupedal gait of climbing because of the demand on the upper limbs and their motorneuron pools to mobilize the organism up the mountain. The interlimb coordination in climbing and crawling biomechanics shares similar features to other quadrupeds, both primate and non-primate, because of similarities in our central pattern generators (CPG’s). New research has however determined that the spaciotemportal patterns of spinal cord activity that  helps to mediate and coordinate arm and leg function both centrally, and on a cord mediated level, significantly differ between the quadruped and bipedal gaits. In correlation to climbers such as Alex however, we need to keep it mind that the quadrupedal demands of a climber (vertical) vastly differ in some respects to those of a non-vertical quadrupedal gait such as in primates and those with Uner Tan Syndrome. This is obvious to the observer not only in the difference in quadrupedal “push-pull” that a climber uses and the center-of-mass (COM) differences.  To be more specific, a climber keeps the COM within the 4 limbs and close to the same surface plane as the hands and feet (mountain) while a primate,  human or Uner Tan person will “tent up” the pelvis and spine from the surface of contact.

What some of the research has determined is that in quadrupeds the lower limbs displayed reduced orientation yet increased ranges of kinematic coordination in alternative patterns such as diagonal and lateral coordination.  This was clearly different to the typical kinematics that are employed in upright bipedal locomotion. Furthermore, in skilled mountain climbers, these lateral and diagonal patterns are clearly more developed than in study controls largely due to repeated challenges and subsequent adaptive changes to these lateral and diagonal patterns.  What this seems to suggest is that there is a different demand and tax on the CPG’s and cord mediated neuromechanics moving from bipedal to quadrupedal locomotion. There seemed to be both advantages and disadvantages to both locomotion styles. Moving towards a more upright bipedal style of locomotion shows an increase in the lower spine (sacral motor pool) activity because of the increased and different demands on the musculature however at the potential cost to losing some of the skills and advantages of the lateral and diagonal quadrupedal skills.  Naturally, different CPG reorganization is necessary moving towards bipedalism because of these different weight bearing demands on the lower limbs but also due to the change from weight bearing upper limbs to more mobile upper limbs free to not only optimize the speed of bipedalism but also to enable the function of carrying objects during locomotion.

The take home seems to suggest that gait retraining is necessary as is the development of proper early crawling and quadruped locomotor patterns. Both will tax different motor pools within the spine and thus different central pattern generators (CPG). A orchestration of both seems to possibly offer the highest rewards and thus not only should crawling be a part of rehab and training but so should forward, lateral and diagonal pattern quadrupedal movements, on varying inclines for optimal benefits.  Certainly we need to do more work on this topic, the research is out there, but correlating the quad and bipedal is limited. We will keep you posted. Next week we will follow up on this quadrupedal topic with a video that will blow your mind ! So stay tuned !

Shawn and Ivo
The Gait Guys

Scand J Med Sci Sports. 2011 Oct;21(5):688-99. Idiosyncratic control of the center of mass in expert climbers. Zampagni ML, Brigadoi S, Schena F, Tosi P, Ivanenko YP.

J Neurophysiol. 2012 Jan;107(1):114-25. Features of hand-foot crawling behavior in human adults. Maclellan MJ, Ivanenko YP, Cappellini G, Sylos Labini F, Lacquaniti F.

Are you a Gait Troglodyte ? Are you sure ?

Are you a Gait Troglodyte ? Are you sure ? You might want to read on.

Most of us are all still in a cave and unacquainted with some of the affairs of the world. Some of us may find ourselves behind the times when it comes to GMO foods, social media, computers and the internet, smart phones while others may be behind on world issues and politics. Heck, some of us have never even seen “Ancient Aliens” on the History Channel !  It is hard to keep up with everything in this fast paced changing world. Something has to give for each of us and so we pick our poison and decide what it is that we are going to have to remain behind on when it comes to the learning curves of the world. And this is alright, but you have to first admit your “back of the pack” and “still living in a cave” type status on the issues and take some ribbing when acknowledging your limitations.  Failing to admit these inevitable shortcomings while pretending that you are still running with the pack can be a real problem. Not only are you faking yourself out but you may be deceiving those that you attempt to help.

Understanding gait, truly understanding it, is a monumental undertaking. This is why there are just no vast resources on it unlike other things in healthcare. Try going to PubMed and type in “arm swing”, you will see 318 articles. Try “pronation”, 2900 articles.  Now try “heart”, 1 million+ articles.  You get the point. Research is behind on gait, and thus our understanding of it is also poorly reflected in functional medicine and  human bodywork.  We are collectively gait troglodytes, living in stereotypical caveman times when it comes to gait.  Sure there are some good books like Perry’s text, or Michaud’s landmark work but there is a void on gait work and research. Human locomotion via gait (walking and running) is a small and poorly understood component by many. It is much the reason why we started The Gait Guys and began writing daily for over 600 days on gait issues. Little did we know that the door we had opened would continue to swing so wide and encompass so many other aspects that feed into human gait.

One of the aspects that worries us the most these days is the growing volume of “functional” work that is going on in the world of therapy and training.  There is a very important and critical place for this work and we fully admit that everyone needs to be on board with all of the great work that the leaders are teaching. What worries us is the apparent lack of integration of this work into gait assessment, gait therapy, and flawed gait neuro-biomechanics. Once again gait is not getting the pulpit it deserves. Yes, flaws in the functional screens and assessments need to be brought to light and remedied because they can impact bipedal locomotion but, the pendulum swings both ways. Gait can often be a cause of these functional problems that show up on the screens and assessments. If one fixes the functional pattern problems and the gait pattern is not restored then either the dysfunction will return or a new undesirable pattern will be generated. There needs to be more gait understanding and assessment from us all. Gait needs retraining as well, it is as much of a functional pattern as any other, if not more.  Gait deserves a pulpit as well.  Human assessment is clearly a two way street and it is not always clear who is the chicken and who is the egg. The problem may be that when gait does have its pulpit to speak from, who is the speaker ? A gait troglodyte or an expert ?

There will be folks who say we are over thinking this issue. There will be some who are offended. There will be some who cheer. There are some that will say “it will all come out in the wash” once the functional patterns are corrected elsewhere. They are wrong, it just is not that simple. Next to breathing, gait may be the second most compromised and corrupted functional pattern that humans express thousands of times daily. So, it is time to get busy.  It is time to peel off your Gait Troglodyte cloak and step into a 3 piece suit when it comes to understanding and interpreting gait.  If you are working in the world of human movement, locomotion, training, rehab and human biomechanics this is your next challenge.  Lets face it, we can either continue to walk around with our 10 year old flip phone understanding of gait or we can step up to a smart phone understanding of gait.  It is up to you, but know where you are and know your limitations. So be honest with yourself and your next client the next time you assess their gait. Be sure to ask yourself after seeing something that just doesn’t seem right in their gait, is what you see really what you are seeing ? Is that really what is wrong ? Or is it a compensation ? Do you know enough to see things for what they really are ?

Shawn and Ivo, The Gait Guys. 

We may not be Gait Troglodytes……. but some accuse us of living in a cave none the less.  However, if you have seen our cave, you will know it looks much like Bruce Wayne’s Batcave.  It isn’t your everyday cave.

Ramblings that go on inside the heads of The Gait Guys.

Random thoughts on gait (and other) motor patterns …….

It is quite possible and reasonable to assume that a motor pattern is a natural mechanism for joint and multi-joint protection.  Consciously trying to alter a motor pattern is likely to drive an improper pattern or one that is deemed unstable by the brain. 

Scenario: client has right foot spun externally into the frontal plane by 15 degrees more than the opposite side.

In this scenario, this could be the reason why merely attempting to turn inwards a right foot that has drifted its way in time outwards does not hold even though it is clearly a deviation from symmetry.  It is likely the fact that the brain, in such a scenario,  has calculated that there is not sufficient stability in a more neutral symmetrical foot progression angle and thus has found the necessary stability in a more turned out position.  As we have always said, subconsciously turning the foot outwards helps to cheat into the frontal plane, likely because that plane is less stable with a neutral foot and with the foot “kickstand” turned out, stability is achieved.  Thus, engaging the foot better in that plane gives the brain and body the perceived and actual stability that it feels it needs to more naturally provide joint or multi-joint stability.  That is not say this is optimal biomechanically for best-case function, but in this picture with all the parts assembled in their present functional ability, this is the optimal pattern.  It is however fraught with risks and probable consequences, and these are what may play out in time to develop into an injury. It is safe to say that the central nervous system (brain etc) will only allow one to place the body and its limbs into positions of perceived stability. We say “perceived” because there are parameters that can fool the brain.  For example, the peripheral neuropathy numbness and loss of proprioception from advancing diabetes can lead to faulty input from the peripheral sensory receptors thus procuring a miscalculated decending motor pattern, and possible placement of the limb in a less than optimal position.  Do not be mistaken, the brain thinks this is an optimal limb placement, but it does not know it did so on faulty sensory information.  The brain assumes that the information is accurate.  This is why you see such horrible fragmented unstable and waivering gait in advancing diabetics.  Their feet can get so numb that there is simply insufficient sensory information to develop any semblance of a clean gait motor pattern.  The same goes with an ACL deficient knee.  The ACL is a major proprioceptor, a major driver of joint position sense.  It is not nearly as detrimental to the motor pattern as advanced peripheral neuropathies but it has a similar effect, just muted.  And in many cases this can be worse. In a high level athlete, this possible lack of obvious awareness of key proprioception / joint position sense can let the athlete get into a potentially dangerous loading position where the joint is at higher risk.  Where as a full blown neuropathy patient knows that such a task is impossible. 

Just some random thoughts…….. internal cortical ramblings of gait crazed madness.

Happy Thanksgiving everyone !

Shawn and Ivo