Gait Recognition

Gait recognition.
Back in university, in my first year, there was a fella on our dorm floor who was basically blind. He could see shapes, light, darkness, figures moving but he could not truly recognize faces until he was about 6 inches from your face. What was amazing though was how quickly he tuned into voice recognition and how we all walked. He could label you from across the room by how you walked it seemed. He had developed a fine tuned sense of movement. I learned something from him by talking to him about this and i use it in my clinic every day when i watch people's gait. Aside from the visual, even the sound of one's foot fall is taken into consideration, there is information there. This is a skill, it comes easily to though who have one of their primary senses, usually visual, blunted. It is about not getting caught up in the details, it is about the quality of the movement of a person that i first glean, then i go back and dissect the details. But, when it comes to the clinical dissection of gait, one has to know all of the time stamp normal gait parameters, the phases, the acts that should occur at each phase, and what should not. If one is a self-labelled gait expert and one cannot spout off the normal phases and what should happen at each phase, and what should not, one should consider down grading their guru label.

"Our brains are especially tuned to see the movements that we and our fellow humans perform and there are particular circuits concerned with perceiving somebody else’s walk, known in the trade as ‘gait’. Studies have shown it is possible to recognise an individual from their walking pattern from any angle. So powerful is the mechanism that even when the walking body is reduced to points of light, carefully placed at the joints of the body, it can still trigger identification, so it may not be the shape or indeed the dress that is the most distinctive feature when it comes to recognising the walker. And we can also reliably infer a person’s emotion from how they walk. "

https://www.theguardian.com/lifeandstyle/2017/may/28/walk-this-way-how-the-brain-recognises-someone-by-their-gait-pippa-middleton

Gluteal tendonopathy and the frontal plane pelvis posturing.

See that foot turned out into the frontal plane ? Ya, all the time. Finding the cause is where the meat is though.

"Individuals with gluteal tendinopathy use different frontal plane kinematics of the hip and pelvis during single leg stance than pain-free controls. This finding is not influenced by pelvic dimension or the potentially modifiable factor of body mass index, but is by hip abductor muscle weakness."

https://www.ncbi.nlm.nih.gov/pubmed/27395451

The Pelvis and COM in locomotion.

"Biomechanics of unobstructed locomotion consists of synchronized complex movements of the pelvis, torso, and lower limbs. These movement patterns become more complex as individuals encounter obstacles or negotiate uneven terrain."

This data was taken on 10 healthy young adult individuals investigation specifically the mechanics of the pelvis, torso, and lower limb segments and how they relate to obstacle negotiation of varying sized objects combined with temporal constraints to perform the task.

The data "revealed a significant increase in sagittal (posterior tilt) and frontal (ipsilateral hike) plane pelvic angular displacement and higher sagittal plane posterior torso lean angular displacement with increased obstacle height. Furthermore, both sagittal plane hip and knee maximum joint flexion were significantly higher with increasing heights of the obstacles during negotiation."

https://www.ncbi.nlm.nih.gov/pubmed/28297177

Hip abductors and pelvis shape.

"The shape of the human pelvis reflects the unique demands placed on the hip abductor muscles (gluteus medius and gluteus minimus), which stabilize the body in the frontal plane during bipedal locomotion. This morphological shift occurred early in hominin evolution, yet important shape differences between hominin species have led to significant disagreement about abductor function and locomotor capability in these extinct taxa." -Warrener

Anat Rec (Hoboken). 2017 May;300(5):932-945. doi: 10.1002/ar.23558.

Hominin Hip Biomechanics: Changing Perspectives.

Warrener AG1,2.

Wiping out the pinky (5th) toe from the evolutionary tree. What the 5th toe does for your COM (center of mass)

Just the other day we saw this article in Popular Science written by Sally Zhang. Sally obviously does not read our blog, but she got a lot of stuff right.

“If you’re born without a pinky toe or have an accident and it’s removed, you can completely do everything you wanted to do,” Dr. Anne Holly Johnson, instructor in orthopaedic surgery at Harvard Medical School, says.

Above you will see a photo of one of the gait guy’s feet. It is quite clear from the photo that competent use of the pinky toe is not necessary for adequate, and possibly exceptionally skilled, foot function. But . . . .

Archived blog link:

https://thegaitguys.tumblr.com/post/96538178584/do-i-really-need-my-pinky-toe-just-the-other

Do I Really Need My Pinky Toe?

Just the other day we saw this article in Popular Science written by Sally Zhang.  Sally obviously does not read our blog, but she got a lot of stuff right.

“If you’re born without a pinky toe or have an accident and it’s removed, you can completely do everything you wanted to do,” Dr. Anne Holly Johnson, instructor in orthopaedic surgery at Harvard Medical School, says.

Above you will see a photo of one of the gait guy’s feet.  It is quite clear from the photo that competent use of the pinky toe is not necessary for adequate, and possibly exceptionally skilled, foot function.  Here, check out this video of our foot in these 2 videos (here and here) for some advanced foot function (sans pinky toe). As you can see in the photo above, this 5th toe has likely never felt the ground, this is a fixed deformity.  Flexor and extensor function of the toe are intact, but it does not reach the ground and so assistance in gaining adequate purchase of the 5th metatarsal on the ground is absent. 

This brings us to a deeper question, what about the 5th metatarsal then? Is it necessary ?  Our answer even without deeper research is a solid “yes”. The foot tripod is severely compromised without the 5th metatarsal. The lateral stability of the foot is impaired without the 5th MET.  The natural locking of the calcaneocuboid joint mechanism will be impaired, the peroneal muscles that provide such critical lateral ankle and foot stability will have fascial planes and tendon attachments disengaged, the natural walking gait lateral to medial foot progression would be impaired, propulsion would be impaired and the list goes on and on. And, not even on the local foot/ankle level. Because, if you take out the function and stability of the lateral foot the hip is very likely to suffer lateral (frontal plane) stability deficits. Meaning, the gluteus medius and abdominal obliques will have more difficulty guarding frontal plane drift when in stance phase rendering all of the “cross over gait” risks (link) highly probable.  

So, not much exciting stuff here today. The presence of a functioning pinky toe does not appear to be critical but don’t take away its big brother neighbor, the 5th Metatarsal or trouble is just around the corner. Don’t believe us? Just ask anyone with a non-union fracture (Jones fracture) of the 5th metatarsal.

The answer goes back to the evolutionary history of humans, explains Dr. Anish Kadakia, assistant professor in orthopaedic surgery at Northwestern University. "Primates use their feet to grab, claw, to climb trees, but humans, we don’t need that function anymore,“ Kadakia says. "Clearly we’re not jumping up and down trees and using our feet to grab. We have toes embryologically, evolutionary for that particular reason because we descended from apes, but we don’t need them as people.”

The gait guys, working with 4 toes on each foot, one step ahead of evolution it seems.

Dr. Shawn Allen

one of the gait guys

reference:

http://www.popsci.com/science/article/2013-05/fyi-do-i-really-need-my-pinky-toe?dom=tw&src=SOC

Video case: Ankle dorsiflexion ? Um, maybe, maybe not.

The more i talk to people about ankle rocker and ankle dorsiflexion, the more i realize they just do not have all the anatomical understanding behind it. But how does one apply the concepts if they don't fully understand it ? It is baffling.
The client should be assessed both passively and actively. When you look at someone's ankles during their gait, do you look at the knee response at ankle dorsiflexion  or at heel rise or during forefoot loading? Do they momentarily hyperextend the knee? Flex the knee? Rotate the foot or leg internally or externally ? To they prematurely heel rise ? Do they prematurely unload the limb and lurch to the other limb thus shortening step length? Do they progress strongly to the lateral forefoot during loading or do they find a middle ground and begin the pronation phase timely with a proper progression to the medial foot tripod ?  Remember, what you see is their strategy, not their problem, do not correct what you see, correct the cause of what you see.

In this video, look at the excessive right knee flexion that occurs here during active ankle dorsiflexion. One must understand what this could mean, and then should be able to see some of the causation during gait. One of the calf complex muscles crosses the knee, one does not. One of them is short on this right side in this client with acute achillies tendonitis. It is not necessarily the cause, but it a piece of the puzzle. Both the clinician and the client do not realize that there is often a knee flexion response during active and passive ankle dorsiflexion assessment, especially when there is mechanical pathology. Having a foam roller under the knee can really bring it out, as in this case. But, remember, this should not be the standard of your assessment, because you are putting slack into the posterior mechanism.

Your big toe is impairing your limb rotation.

Hallux limitus and impaired limb rotation.
No rocket science here, but always good to remember the mechanical principles.
If you cannot get over the medial foot tripod cleanly, for whatever reason, be it loss of 1st MPJ ROM (hallux limitus) or because of pain or forefoot typing issues, or you will be impairing normal rotation of the entire limb. In the above cases, remaining perhaps in more relative external limb rotation, impacting gluteal function. But, going too fast and too far over the medial foot tripod without controlled loading through that region can be just as detrimental, too much internal spin. Stuff we pound sand on all the time.
 

J Am Podiatr Med Assoc. 2011 Nov-Dec;101(6):467-74.

Hallux limitus and its relationship with the internal rotational pattern of the lower limb.

Lafuente G1, Munuera PV, Dominguez G, Reina M, Lafuente B.

When they walk back. What we are not aware of.

Here is a little something we do, all the time. When the session room is open for the next client, we greet our client in the lobby. We do not have our staff send them back to the room to change and wait for us. We watch them closely. How do they stand up, how do they initiate their gait cycle ? How is their balance? How do they carry their things ?
We ask them to head back to the session room to get changed, while we grab a drink of water. And then, in a sneaky manner, we watch them walk back to the room.
We do this, because, how we walk when we do not think we are being watched, when we are carrying our things (purse, phone, bottle of water, backpack, etc) is how we typically walk. Clients will show all the goodies we need to see: the turned out foot, the hiked shoulder, the limps, the staggers, stumbles, speed, step width, and the like. We also get to see how they move in the shoes they live in, the heeled ones, the broken down ones, the work shoes.

So, when your client is having a formal treadmill gait analysis, what are you seeing? Their best behavior, or the truth ?
There are clues everywhere, and we try to grab all of them, in as natural a manner as possible.
Just some simple thoughts for a Sunday.
Have a great day friends !

To Post (an orthotic) or not to post. That is the question

We have been tinkering with medial and lateral rearfoot and forefoot wedges for decades now collectively.
I would have to say that some of my greatest learning came from taking orthotics and foot beds and modifying them with various wedges (cork postings) and then asking the client how the changes impacted their gait and their pain somewhere in the kinetic chain. It was a huge learning curve, but without question, an invaluable one. I would do it all over again. It is also what allowed me to mostly get away from orthotic solutions for most clients. Because, armed with the knowledge at the foot-ground interface and then understanding how the muscles drive, slow, protect, co-contract etc I was able to melt the information into a package that much of the time, and hopefully, drives the client towards a solution, or at least more sound, stable and pain free function. If you are having someone make your orthotics and placing posts on them for you, there is a huge learning curve missing here for you. And, you are likely gonna get the prescription wrong, often. Trust me, often. We feel you should be playing these games yourself, one on one with the client, immediate feedback, immediate changes and teamwork. But, what do we know.

https://jfootankleres.biomedcentral.com/articles/10.1186/s13047-017-0201-x

Quiz: Walking sideways on a slope

Saturday morning fun Test Q#2:
Arm and leg swing gait quiz. Today we combine concepts from our previous quizes ! This one may really put you to the test.

Two women walking on a sloped beach. They are arm in arm.

Take the principles we have taught you on slope walking, functional leg length differentials to level the pelvis, and arm swing to answer the question.

Here is the question: Are these two more likely to walk “in phase or out of phase”?

* Do not mistaken the question for anti-phasic or phasic. These are two different concepts. If you are out of the loop on these 4 terms, just search the blog for them. Then come back here to answer this brain thumper.

Make for your case in your head and then scroll down to hear my reasoning for my answer.

Link to the answer:  https://thegaitguys.tumblr.com/post/144197829694/arm-and-leg-swing-gait-quiz-today-i-combine
 

Arm and leg swing gait quiz. Today I combine concepts from my previous quizes ! This one may really put you to the test. 

Two women walking on a sloped beach. They are arm in arm.

Take the principles I have taught you on slope walking, functional leg length differentials to level the pelvis, and arm swing to answer the question.

Here is the question: Are these two more likely to walk “in phase or out of phase”? 

* Do not mistaken the question for anti-phasic or phasic. These are two different concepts. If you are out of the loop on these 4 terms, just search the blog for them. Then come back here to answer this brain thumper.

Make for your case in your head and then scroll down to hear my reasoning for my answer.

This is an EXTREMELY difficult mind bender of a question. You will need to understand the concepts of 2 prior blog posts to even get to the starting line of the solution.  These are the questions I will often pose to myself so that I force the mental gymnastics of gait biomechanics, and quicken my “gait mind” so that I can leave room for processing unique factors in someone’s individual gait. If you have to take time to process the basics, you are gonna run out of time during a consultation and your client will notice you scratching your head. This is a maturation process, you must put in the work that Ivo and I have, if you want to solve the really tough cases. Simple cases are a break, a vacation if you will, they are welcome during a clinic day, but it is the tough cases that make you stretch that truly fulfill your day.  When you are in the clinic, you have to think fast, efficiently and effectively. Recently I had a powerlifter drive from out of state to see me. His case problems were unresolved for many years.  The treating clinician was on the right page, doing a great job actually, but there were so many issues going on that it was hard to see the root of the problem so the case was just being more “managed” than solved. His case was much like this one, all of the findings and factors were related but because I had seen this hodge podge of complaints before (right foot, right knee, left hip, low back, pelvis distortion and a classic Olympic lift compensation fail) so I knew quickly how to piece it all together into a logical solution and find the single spot to focus the therapy, at the root of the problem. My point is that I had done the hard “head scratching” work long ago, so I readily was able to dismiss the distractors and recognize this beast for what it was.  

Back to the two ladies beach walking, I am basing things on a simple assumption that on most beaches the slope gently levels out at the water line, and that the sand several feet up the beach from the water is on a steeper incline, simple tide erosion principles.  Thus, the woman higher up on the beach will be on a steeper slope, this means more beach side leg knee flexion which means less hip extension, meaning a shorter right step length.  This will impair left arm swing, likely shortening it. Less right hip extension will be met by less left arm extension (posterior arm swing behind the body). This often leads to left arm cross over, arm adduction. 

Here is where things get squirrelly. The lady lower on the beach is on a slightly more gentle slope but her issues are the same just muted slightly. So her right beach side leg is in less flexion at the knee and hip, so hip extension is greater and step length will be longer (relative to her friend higher up on the beach). However, she (ocean side lady) is being led by the impaired arm swing, as discussed above, of the lady on the beach side.  That is, if in fact she is being led or if she is the leader. Oy ! There is the brain bender !  

One must consider who is the more corrupting force. In this case, the more corrupting forces will likely trump out the cleaner forces. The ocean side lady is clearly going to have a “more normal” gait with more normal arm and leg swing and step lengths, quite simply the slope she must negotiate is less so there is less corrupting forces on her. The lady on the beach side is having to accomodate more to her greater slope. The lady up the beach is working harder to keep her pelvis level, her eyes and vestiular apparati on the horizon, her differing step lengths from pulling her off from a straight line course, to keep her from falling over (the steeper the slope, the greater the balance challenge to fight from falling into the beach or falling down the slope. Laws of physics say that things roll down hill, so she is fighting this battle while trying to walk a straight line down a sloped beach, with a friends arm in tow).

So, with all that said, one could logically assume that the gal up the beach is definitely working harder, she has greater differing arm and leg swings from side to side, different step lengths, greater struggles with staying up on the slope when gravity wants her to move down the slope, she has more left arm flexion and adduction to help pair with the struggling and perpetual right hip flexion (and loss of right hip extension), she will have to demonstrate more spinal stiffness to deal with these limb girdle torsional differences side to side and a host of other issues I have outlined in these prior “beach walking” quiz posts. Clearly beach side lady is working harder. Thus, just to maintain her gait posturing up on the slope, she will have to dominate the gait. If she gives in to the signals of her ocean side gal, she will have to soften her slope work strategies and she will move down the slope to easier ground. 

Now, back to the question: Are these two more likely to walk “in phase or out of phase”? 

Who truly knows is the answer ! However, we know beach lady is working harder and must continue to do so to stay up on the slope, so her left arm will remain dominant and the ocean side gal will have to accommodate to a very jerky yet cyclically synchronous gait. To walk linked together they will have to find some rhythm. Walking slower will be easier for them to find a harmoniously rhythm. However, one could make the case that “out of phase” gait will be easier (mental image to help you, if they tie ocean side lady’s right ankle to beach side ladies left ankle you will create “out of phase” gait. Thus, the ocean side lady will not mirror her beach side friend. Thus, when beach lady has right leg in extension, ocean side lady will have her left leg in extension. Why? Well, the left arm swing , their point of union, is the trouble zone. With beach side lady having the left arm in more flexion and adduction, the ocean side lady has to accommodate and meet that troubling arm swing. This means her right leg will be in extension at the same time beach side lady has her left leg in extension. This will be more accommodative work for ocean side lady, but she will just have to go with it. Failure to do so will pull her friend down off the beach and making life harder for her friend.

So there you have it. The person up the slope is working harder to stay here, the person down the slope is working harder to accommodate to a gait that their  lower slope is not requiring. Thus, they are both working hard, but for different reasons. But the winner, the dictator, is the one with the greater slope risk. And thus, she will dictate an “out of phase” gait of her ocean side partner, if they are to still walk embraced. 

How did you do ? Can you make a case for “in phase” as the solution ? I can, but I think that “out of phase” is more likely, for the above reasons.

Thanks for playing  this tough one. Congratulations to you if you followed things smoothly. IF you did not, go back and play the mental game again, I think these are important fundamentals everyone should have if you are doing gait work.

Dr. Shawn Allen

Presence of Bacteria in Spontaneous Achilles Tendon Ruptures.

Presence of Bacteria in Spontaneous Achilles Tendon Ruptures.

Here is one to ponder, especially since we just did our last podcast on the achilles rabbit hole.
This study seems to only show correlation.
Which leaves us all with open ended questions, such as, was there a preceeding infectious vector ? Such as in this article here, albeit rare, where the infection likely came from elsewhere, seeded if you will ? (https://www.ncbi.nlm.nih.gov/pubmed/24529751)

There are still some mysteries around achilles ruptures, but these articles suggest a preceeding infection seeding that might disrupt the tendon matrix might set the stage in some. Maybe.

https://www.ncbi.nlm.nih.gov/m/pubmed/28355086/

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

Quadruped Patterns: Part 1 (redux)

Quadruped Patterns: Part 1
If you have been with us here at The Gait Guys for awhile, 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.

Lets get into it, full blog post here,

https://www.thegaitguys.com/thedailyblog/an-alternate-view-of-crawling-and-quadrupedal

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.

More on Plantar Pressures

Yes, an hour dialogue just on a picture of two feet, one person, and two feet of different length and size, like most of us. Yes, most of us.
Yes, it is a static picture, but we went down the rabbit hole and played with all of the topics below to dissect possibly why this person had 2 different length feet and vastly different plantar pressures statically.

Last night we pressed some clinical minds hard, and fast. It was a rapid hour playing mental gymnastics for an hour basically off of one slide, this slide. A "normal" everyday person standing on a glass plate. How did we talk for an hour on basically one slide ? Well, in about a week you can look up Biomechanics 322 and watch it yourself on the onlineCE.com platform.
We discussed, step length, quadratus plantae, fat pad displacement, achilles problems, flexor longus dominance, toe box spacing, hammer toes, unilateral frontal plane pelvis displacement, plantar pressure shifts, windswept biomechanics, pelvis distortion patterns, tibial and femoral torsions, pronation, supination and many other things. Yes, these things all came up, basically from this one slide.
If you are doing static plantar mappings in your office, you need to watch this presentation, your mappings are not telling you what you think they are. Come join us, we will prove it. Let us help you change the way you practice.

The Quad Walkers: Those that walk on all 4's

The quad walkers.
Last night in our onlineCE lecture a slide popped up reminding us of this syndrome and some unique things we should all delve into about quadrupedal locomotion. I wrote a multipart series on Uner Tan Syndrome, the people who walk on all fours. IT was long ago, but it is likely 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/thedailyblog/the-hand-walkers-the-family-that-walks-on-all

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 and the video clip above was 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/doi/abs/10.1080/00207450701667857

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

http://www.ncbi.nlm.nih.gov/pubmed?term=Uner%20Tan%20syndrome

Short leg and Pronation

Dr Allen was ON FIRE on tonites onlinece.com lecture Biomechanics 322). Hope you will join us again (or next time if you missed us). We talked about many of the aspects of a static exam and how it effects weight bearing in the foot. The word "short leg" came up more than once, and yes, from Dr Allen : )

Remember, as the foot pronates more on one side, the center of gravity will move medially. You will often see more toe clenching (and resultant quadratus plantae weakness) on the more pronatory side and more toe elongation on the more supinatory side. You will often also see more splay and elongation on the pronatory side, and less elongation and less splay on the supinatory side. Remember, these are guidelines and not rules, and there are ALWAYS exceptions.

Myokymia

What in the world ?!?!?
We follow some pretty smart people on Twitter, probably like you do. In recent marathons this strange phenomenon was noted. There as been some great thought and productive chatter on what this might be.
One postulation was this:
Myokymia, a form of involuntary muscular movement, usually can be visualized on the skin as vermicular or continuous rippling movements
Another reasonable one was that with a fast shutter speed it could just be a fascial.fatty, skin/ muscle interface rippling effect after a loading response. Yes, even though the appearance is on the swing leg.
It certainly is strange and we are doing our homework into possibilities like the other wisemen/women.
Certainly, you will see similar horizontal striations in bodybuilders with low body fat, but we wonder about that hypothesis because those are more individualized to the different muscle bellies, this appearance here seems to span the entire quad and the rectus femoris just isn't that hearty we believe.

Have you seen it ? Thoughts ? Brainstorm . . . .

Thanks Ross Tucker, Adam Meakins and the others for a fun topic to ponder.

http://emedicine.medscape.com/article/1141267-overview#a4

https://twitter.com/scienceofsport/status/854241624997724161

Kidney injury & Running

For all you distance athletes who think you are invincible . . .

"The researchers collected and analyzed blood and urine samples from runners in the 2015 Hartford Marathon. Eight-two (82%) percent of the participants displayed Stage 1 Acute Kidney Injury or AKI. That means kidneys aren't properly filtering waste from blood. It can, in turn, affect other organs like the brain, heart and lung, according to the National Kidney Foundation.

"The kidney responds to the physical stress of marathon running as if it's injured, in a way that's similar to what happens in hospitalized patients when the kidney is affected by medical and surgical complications," Dr. Chirag Parikh, the study's lead researcher, said in a Yale news release. "

article: http://www.ajkd.org/article/S0272-6386(17)30536-X/fulltext

http://www.newsweek.com/running-bad-you-marathons-damage-kidneys-runners-bodies-575829

Running and Life Expectancy

Can running 2 hours a week, generate an increase in life expectancy of 3.2 years, for a net gain of about 2.8 years.? This study suggests so.

"Cumulatively, the data indicated that running, whatever someone’s pace or mileage, dropped a person’s risk of premature death by almost 40 percent, a benefit that held true even when the researchers controlled for smoking, drinking and a history of health problems such as hypertension or obesity.

Using those numbers, the scientists then determined that if every non-runner who had been part of the reviewed studies took up the sport, there would have been 16 percent fewer deaths over all, and 25 percent fewer fatal heart attacks. (One caveat: the participants in those studies were mostly white and middle class.)

https://www.nytimes.com/2017/04/12/well/move/an-hour-of-running-may-add-seven-hours-to-your-life.html?_r=0

Arterial blood flow of the lateral thigh increased significantly after foam rolling exercises compared with baseline

Arterial blood flow of the lateral thigh increased significantly after foam rolling exercises compared with baseline"

There are those in the camp that foam rolling is a waste of time, and those who swear by these various methods of self-soft tissue work. We are in the camp that it is helpful, but more so, if it seems to work for you then do it often. There have been journal articles in the last year that deep soft tissue within an hour of an aggressive workout helps recovery, which supports our camp. This is just one more piece supporting that "doing something" is better than a sofa, beer and Doritos.

Acute Effects of Lateral Thigh Foam Rolling on Arterial Tissue Perfusion Determined by Spectral Doppler and Power Doppler Ultrasound
Hotfiel, Thilo; Swoboda, Bernd; Krinner, Sebastian; Grim, Casper; Engelhardt, Martin; Uder, Michael; Heiss, Rafael U.
The Journal of Strength & Conditioning Research: April 2017 - Volume 31 - Issue 4 - p 893–900