Gait Guys/IRRA Running Event Recap

Well, it was a fast a furious 2 days for us. We arrived Tuesday evening and put the finishing touches on the presentation for Wednesday morning. We were up and lecturing, 8AM Texas time and were very well received with many interesting questions. This was one one smart group of retailers!

We then had a photo session and whisked off to the Austin School of Film (Thank You Anna, KIrk and Brian!) to finish filming the rest of the Shoe Fit Certification Program (Excerpts to be posted soon!). A few hours later we were back at the event and met up with Dr Mark Cucuzella (a good friend and colleague of ours; you have seen his videos here on the blog) and David Jonson from Sole Running. We were then off to a mixer and out to dinner with Dick Beardsley (yes, THE Dick Beardsley from the 1982 Boston Marathon with Salazar), his wife, Curt Munson and Daren DeCavitte from Playmakers, and Dr Mark. Thursday morning was filled with meetings, including a Magazine interview with Max Lockwood of the Georgetown Running Company. Then we were off to the airport by 2PM and away we went. We have full days at the clinic today and are looking forward to some much needed rest (and a lot of film editing!) this weekend!

Thanks again for all your support.

Ivo and Shawn

The Krebs cycle rap→

It is Friday Follies !

here is one for all of you who were tortured in high school and college with the Krebs cycle. Yup, nothing clearly dealing with gait, perhaps gait energy production however.

It geek stuff and so we appreciate it. !

“Arm Swing Part 2. “When Phase is Lost”.

* Important: (this is a continuation of yesterday’s post, December 7th. You must read Part 1 from yesterday to have any chance to make sense to today’s post.)

So, we are back to looking at limb swing again. It is important for you to realize, as put forth in

Huang et al in the Eur Spine Journal, 2011 Mar 20(3) “Gait Adaptations in low back pain patients with lumbar disc herniation: trunk coordination and arm swing.”

that as spine pain presents, the shoulder and pelvic girdle anti-phase (as in drawing above) begins to move into a more “in-phase” favor.  Meaning that, the differential between the upper torso twist and pelvic twist is reduced (in the drawing above the lines will laterally converge). IF this anti-phase is reduced then arm swing should be reduced (half truth, this is a topic for anther time). The central processing mechanisms do this to reduce spinal twisting, because reduced twist means reduced spinal motor unit compression and this hopefully leads to less pain.  This also means reduced thoracic mobility unfortunately (think about this the next time a shoulder assessment test directs you to the thoracic spine and rib cage mobility). The consequence to this reduced spinal rotation is reduced limb swing.  Think about this next time you see someone, a runner patient or athlete, with reduced arm swing especially on one side. Furthermore, according to

Collins et al Proc Biol Sci, 2009, Oct 22

“Dynamic arm swinging in human walking.”

normal arm swinging requires minimal shoulder torque, while volitionally holding the arms motionless requires 12 % more metabolic energy, proving that there are both active and passive components to arm swing.  Collins also discovered that among measures of gait mechanics, vertical ground reactive moments are most affected by arm swinging and increased by 63% without it. Wow, 63% !

So, it is all about efficiency and protection. Efficiency comes with fluid unrestricted movements and energy conservation but protection has the cost of wasting energy and reduced mobility through a limb(s) and spine.

Now, digest all of this and we will talk about primitive and modern day man next time…….. think about it…. carrying spears and briefcases, or runners carrying a water bottle for that matter.   There is more to this arm swing thing than we are letting on here, but you have to digest this first. Please, take the time to re-read this and yesterday’s post and really “get it” because this is going to likely get a bit complicated.  But if you take the time to digest this you will never look at an athlete or patient the same again. Your patient assessments will grow deeper and have more clarity.

There is a reason that in our practices we often assess and treat contralateral upper and lower limbs. If you are paying attention, these in combination with the unilateral loss of spinal rotation or lateral flexion are the things that need attention.  And for those out there that do not think that the foot is important (we can think of at least one industry guru who thinks it is a “non-factor”), think about this:  When there is insufficient hip rotation unilaterally you can regain some of the loss through increased foot pronation unilaterally.  The problem with this is that you compromise the swing phase on the contralateral side when you do that and quire often create an abductory foot twist on the hyperpronated side (due to firing of the medial head of the gastroc to invert the foot and assist in supination). However, if you are trying to walk in a straight line from A to B, you also have yet another option, a subconscious option of putting a axial spin through the whole body, some call this pelvic distortion patterning or pelvic obliquity.

OK, that should keep your heads swimming for awhile until the next post on arm swing.  It is not as simple as telling your athlete to swing one arm more, or to stop pulling it across their body; they need to do those things, it is called a “compensation”.  Merely addressing that locally is such a crime.  If you are seeing an arm swing change, you would be foolish not to look at the opposite lower limb and foot at the very least, and of course assess spinal rotation, thoracic extension and lateral bend, …..all spinal functions for that matter.  For your neuro nerds, remember the receptors from the central spine and core fire into the midline vermis of the cerebellum (one of the oldest parts of our brain, called the paleo cerebellum); and these pathways, along with other cerebellar efferents, fire our axial extensor muscles that keep us upright in the gravitational plane and provide balance or homeostasis which the ancient Chinese called Yin and Yang.

Simple log-rolling type patterns on the floor or the spine assessment pattern of your preference will likely show a difficulty or asymmetry unilaterally.  Think of the neurological implications of long term unilateral asymmetry, altering neuronal plasticity, and altering our movement patterns (and thus our compensations). Make sure to  couple this with specific muscle testing to be as clear as you can. Too many folks rely solely on movement assessments but that can catch you in a lie quite often because you could be seeing a compensation.

Yup, we are The Gait Guys….. we have been paying attention to this stuff long before the functional movement assessment programs became popular.  If you just know gait well enough, one of the single most primitive patterns other than crawling and breathing and the like, you will understand why you see altered squats, hip hinges, shoulder ROM screens etc.  You must have a deep rooted fundamental knowledge of the gait central processing and gait parameters. If you do not, every other screen that you put your athlete or patient through might have limited or false leading meaning. 

Shawn and Ivo …  combining almost 40 years of orthopedics, neurology, biomechanics and gait studies to get to the bottom of things.

The Perfect Running Shoe.

On November 17th we provided this description for Kara Thom in an article she wrote. If you want to see her complete article, head to our archives and find that post for November 17th or click here. for her full article.

Here was our small contribution to her nice piece.

The perfect shoe is one that blends seamlessly with your unique biomechanics without creating a conflict between the foot and shoe. It should complement your strengths yet be as comfortable as a bedroom slipper. The shoe should not attempt to alter the natural playing field, meaning, that the heel and forefoot shoe be relatively on the same plane. The closer the forefoot and heel are to the same plane of function, the fewer the compensations from your foot’s natural biomechanics. The perfect shoe should have some cushion, but not too much. Studies show excessive EVA foam in a shoe can increase impact forces due to biomechanical changes. The perfect shoe should not attempt to control the foot, for that will weaken the foot’s intrinsic strength. Thus, part of finding “the perfect shoe” entails realizing your foot’s deficits and limitations. Shoe fit is a science and an art. Because no two feet are the same, there is no perfect shoe for all foot types. There are multiple foot types all based off of 4 primary parameters: rear foot varus, rear foot valgus, forefoot varus and forefoot valgus. Throw in some anomalies, old injuries, variations in length and height of the arches, some variations in joint flexibility and functional control as well as some weaknesses and you can see why the algorithm for the perfect shoe spreads pretty wide pretty fast.

Shawn and Ivo, The Gait Guys.

Arm swing in gait and running:  Part 1.

There is so much more to it than you could ever have believed !

Here are some of the facts in NORMAL gait:

1. ipsilateral arm and leg swing are in anti-phase (out of phase) meaning that in the picture above the left leg is in flexion and external rotation while the left arm is in internal rotation and extension. (You cannot tell that the left leg is in external rotation but we know that normal gait parameters dictate a lateral heel strike and external rotation.)
2. contralaterally the left leg and right arm are in-phase.
3. the shoulder girdle and pelvic girdle are in anti-phase as well. See the arrows overlaying the drawing. This means that, as in the picture above, as the left pelvic girdle (left hemi-pelvis) is anterior (since it moves anterior with the same side leg flexion) the left shoulder girdle is posterior. These anti-phasic motions should be equal and symmetrical bilaterally, if gait is normal.
4. * so if you are paying very close attention you will note that:

•  the left leg is in flexion and external rotation just like the right arm (flexion and external rotation/supination).
• thus, the right leg is in hip extension and internal rotation just like the left arm.

• This drives the oblique posterior muscular sling from right gluteus to left latissimus/lower-middle trapezius via the multi compartmentalized thoracolumbar fascia. Long ago this was coined the Back Force Transmission System. It was discussed in detail in the Second Interdisciplinary World Congress on Low Back Pain, 1995 (link) which all gait geeks have likely read a few times.

Now, many of you who are in the fields of manual and movement therapies are going to say, “guys, tell us something new and fresh, please ! This is old info going all the way back to Serge Gracovetsky’s "Spinal Engine” 1989 book.“ 

Yes, we know this stuff is old hat. Gracovetsky’s book was a great read, we just wish it had been longer in pages.  But, did you know what these works were asking you to extrapolate from them ?

Perhaps they were reminding us of things like: Internal hip rotation is a precursor to hip extension.  In other words, the hip must pass through the internal rotation phase before it starts into hip extension.  This means that the opposite shoulder must do the same thing. Go ahead, get up and walk and you will note it yourself.  But what you must realize is that if shoulder internal rotation range is lost or limited then the posterior sling will be insufficient and hip extension cannot be achieved as effectively. It works both ways gang ! Remember, it is not only a mechanical phenomenon, it is a centrally mediated neurological phenomenon as well.  So, if you are thinking outside of the box you might realize that a frozen shoulder (adhesive capulitis) perhaps cannot be treated effectively or completely if contralateral hip extension or internal rotation are limited.  They feed forward and feed backwards between each other as well; functional hip pathology can drive shoulder functional pathology.  And so if you try to treat a frozen shoulder without paying attention to the gait neurologic central processing patterns then you can sometimes get the slow progress that is seen by many.  Think about this the next time you look at a functional shoulder assessment pattern ! We look at the contralateral hip and gait patterns first and correlate ! Treat the person, not the symptom.  And gait is part of how they move and integrate the parts.

Tomorrow we well talk more about arm swing, in "Arm Swing Part 2. "When Phase is Lost”.

Shawn and Ivo …  combining almost 40 years of orthopedics, neurology, biomechanics and gait experience to get to the bottom of things  …  and put it into a digestible form for you.  (and sharing some of this in Austin Texas today as speakers at The Running Event…. the nations largest running event.)

"Using Kinect for Xbox 360 and Computer Vision to Analyze Human Gait,"→

Really !? Now we (and you) have an excuse to get an XBOX 360 and Kinect !

According to Young-Hui Chang, associate professor of applied physiology at the Georgia Institute of Technology, “In the rapidly developing field of gait analysis in prosthetics and orthotics, their project opens avenues to bring personalized rehabilitation to the home. This could potentially reduce medical costs, allowing clinicians to monitor a patient’s progress from a remote site.”

see the link above !

The Gait Guys: Toe Box Sizing Talk, and case study.

Here Dr. Shawn Allen of The Gait Guys talks about some of the basic components of the shoe toe box. He discusses some of the problems in the Western world with improper shoe fabrication and toe box fit and shape. Then he shows a case of a hallux valgus where the distal toe length is shifted laterally into abduction (generally speaking) and with the combination of a widening of the forefoot the subsequent foot length is reduced. Comparing this to the opposite foot shoes that quite often with unilateral pathology foot wear sizing needs some deeper thought, awareness and wisdom. Look for The Gait Guys advanced Shoe Fit DVD program on their website starting in 2012.

Intelligent design.

“I have a bone to pick with God. If He designed the human body, why did he route the male urethra directly through the middle of the prostate gland, thus causing incredible problems for men as they advance in years.” Anon

“Unintelligent or incompetent design.” That is how Cornell evolutionary biologist Paul Sherman refers to the architecture of the human body. If an “intelligent designer” engineered the human body, he points out, air and food would not travel through the same pipes, making us vulnerable to choking.

After teaching seminars on Darwinian medicine (Neurobiology and Behavior 420 this semester) for more than a decade, Sherman, professor of neurobiology and behavior and a Weiss Presidential Fellow, has developed such insights into the workings of the human body and why things are the way they are. They are quite counter, he says, to the idea of intelligent design – the controversial idea that some things in nature are too complex to be explained by natural selection and, therefore, must be the work of a deity – an intelligent designer.

“As soon as you begin to look at our bodies from an evolutionary perspective you see more and more we are not intelligently designed,” said Sherman. For example, he pointed out that no engineer would design our throats with a windpipe that crosses the tube where food passes. “If you were going to design this to eliminate choking you’d probably put your mouth in your forehead or your nasal opening in your throat. It [the human body] is as one would expect from random mutations of previously existing structures and selection over eons.”
This new approach questions which symptoms the body has acquired because they are useful adaptations and which truly are pathologies………… The Darwinian medicine approach “takes every symptom and asks whether it is pathological or the body’s adaptive response,” said Sherman. The approach questions, for example, if a common cough is serving to rid the body of infection or if it is instead a mechanism by which the disease spreads itself.

Our bodies break down a lot. If we were designed more intelligently, presumably we wouldn’t have osteoporosis or broken hips when we get old. Some evolutionists suppose that the process through which people evolved from four-legged creatures to two, has had negative orthopedic consequences.
We are flawed cardiovascularly. Horses carry much more oxygen in their blood, and have a storage system for red blood cells in their spleens, a natural system of blood doping. Humans don’t. Also, while a lot of aerobics can make our hearts bigger, our lungs are unique. They don’t adapt to training. They’re fixed. We’re stuck with them, and can only envy the antelopes.
All of our pelvises slope forward for convenient knuckle-dragging, like all the other great apes. And the only reason you stand erect is because of this incredible sharp bend at the base of your spine, which is either evolution’s way of modifying something or else it’s just a design that would flunk a first-year engineering student. 
Look at the teeth in your mouth. Basically, most of us have too many teeth for the size of our mouth. Well, is this evolution flattening a mammalian muzzle and jamming it into a face or is it a design that couldn’t count accurately above 20? 
Look at the bones in your face. They’re the same as the other mammals’ but they’re just squashed and contorted by jamming the jaw into a face with your brain expanding over it, so the potential drainage system in there is so convoluted that no plumber would admit to having done it! 

Well, for one thing I would put fewer teeth in our mouths. I would put fewer bones in our face, so that it could drain properly. I would straighten up the pelvis so we wouldn’t have to have that bend. I would certainly take out the appendix so we don’t have that problem and the tonsils, too. 
And I did have one other. Some guy from Texas listed a number of things with this and he said, “Actually I would write more, but I have to go pee in Morse code, because some idiot designed my aging prostate."        …..talk about the wonderful design of the eye—which somehow has all your receptor cells behind a membrane curtain! 
I mean, evolutionarily all of these things make sense but in terms of a reasonable, intelligent design? They’re idiocy.”

This is not the work of The Gait Guys……we cannot even find the source where we obtained this…… it is something we found floating in our archives. “Thinking outside the box” kinda stuff…… stuff we really appreciate. We will be looking for the original work so we can give credit and read more of their stuff. Go ahead and see if you can find more stuff on their work.  It reminds us of a few books we read a few years or so ago…… “The Scars of Evolution” by Elaine Morgan and “The Naked Ape” by Desmond Morris.  They bring to mind similar thoughts as to how, why, and if man had the right to move from quadripedal to bipedal. (if you believe in evolution that is … and if you do not, then you are either a fan of God creation events …  and if you believe in that theory then we will ask you to consider watching our favorite History Channel show “Ancient Aliens”.  That will surely shake up things a little for ya !  Just having fun with ya’ll.  As we respectfully say, ‘To Each His Own.’.

Shawn and Ivo

Speaking of Lactate….

Here’s the bottom line from Professor Brooks: “The world’s best athletes stay competitive by interval training. The intense exercise generates big lactate loads, and the body adapts by building up mitochondria to clear lactic acid quickly. If you use it up (as an energy source), it doesn’t accumulate.”

The job of the athlete is to train in a way that causes the mitochondria to process lactic acid faster and more efficiently.

Lactic acid is a fuel. To improve your capacity to use it as a fuel, you must increase the lactic acid load very high during training. (For more details, see my earlier article:http://www.cbass.com/Lacticacid.htm )

Dr. McGuff is on top of this new thinking. He says that high-intensity intervals and high-intensity strength training both perform the same function: they improve aerobic function by forcing the mitochondria to burn lactic acid more efficiently.

“It is during ‘recovery’ from high intensity exercise that you’re actually getting an increased stimulation of the aerobic system equal to or greater than what you would get from conventional steady-state ‘aerobic’ exercise,” McGuff writes.

“If you have been subjected to proper physical training, you can actually make good use of the lactic acid that is produced. If you are intent on improving your aerobic capacity, it’s important to understand that your aerobic system performs at its highest level when recovering from lactic acidosis,” McGuff adds. “It is also important to understand that since muscle is the basic mechanical system being served by the aerobic system, as muscle strength improves, the necessary support systems (which include the aerobic system) must follow suit.”

To improve the ability of your aerobic system to use lactic acid as a fuel, McGuff says: Lift weights. And then, let your mitochondria take over from there. Get your aerobic benefit on the “drive home from the gym or off to lunch or back to work.”

For McGuff, productive exercise begins and ends with strength training. THE key stimulus for strength—and aerobic fitness—is high-intensity muscular effort.

To see and hear Dr. McGuff explain, in 5:50 minutes, just about everything we’ve talked about so far—and why he believes ‘cardio’ really doesn’t exist—visit You Tube: http://www.youtube.com/watch?v=RiHhc7eLpQY  

we tried to link this from  our friend Peter’s Runblogger site…… there was a “share” link problem. 

Great link Pete !

Evidently, we are not the only people who find feet sexy.

http://ngm.nationalgeographic.com/ngm/0609/feature2/online_extra05.html

Here is an interesting National Geo Article contrasting and comparing the shoe and the foot: which is sexier? You decide for yourself.

Two guys, usually liking feet more than shoes….The Gait guys

Something lighter for Friday Follies. 

It just goes to show. You don’t need to be the fastest, just faster than the the slowest guy. Enjoy your Friday!

Ivo and Shawn

The physics of heeled shoes. (or, “Using Newton’s Laws to determine sole pressure.”)

Did you know that a 110 lb. woman wearing stiletto high heel shoes puts a lot more pressure on the ground than a 6,000lb elephant?

First lets begin with Newton’s laws of motion. They are three physical laws that form the basis for classical mechanics. They describe the relationship between the forces acting on a body and its motion due to those forces. They are summarized as follows:

1. First law: The velocity of a body remains constant unless the body is acted upon by an external force. Meaning that a body stays at rest or in motion unless forced to do otherwise.
2. Second law: The acceleration of a body is parallel and directly proportional to the net force F and inversely proportional to the mass m, i.e., F = ma.
3. Third law: The mutual forces of action and reaction between two bodies are equal, opposite and collinear.

Now, we all know these laws well but here is something a little different today. Today we have lovely Dr. Deborah Berebichez  the first Mexican woman at the Stanford University graduating with a doctorate in physics. Here she gives a simple dialogue of the application of these 3 laws to footwear.

In her PhD dissertation physicist Berebichez developed a new method for electromagnetic waves to focus with extreme accuracy in space and time. Berebichez is currently researching at the Courant Institute of Mathematical Sciences of New York University . 

Our point ? This is a brilliant woman and so when she speaks about the physics of high heeled shoes, you should listen.  5 inches is the max ladies (oy vay !)

h(max)=Q (12 + (3s/8))

but remember, this the maximum height to stay stable and not risk falling over. It has nothing to do with the risk of pain and pathology to the body that will occur over time ! But that is another mathematical equation that might be best suited for our other favorite fellow-geek and mathemetician Garth Sunden @ Geek Logik who can figure out any formula for anything you wish to assess (for example, “What are my chances in scoring a date with a girl at a bar? click here).

Watch her video attached here to learn about Newton’s 3 laws and how they apply to shoes and heel height.  It is great stuff !  It is important to note that even in the highest of women’s heeled shoes heel strike still occurs first (although it is softened as heel height increases……don’t bother asking us how we know this please), hence Berebichez’s point on heel pressure stands correct but somewhat muted.  Heel strike does not however necessarily mean true impact.  We encourage our patients to note the difference between heel impact and contact. Just because in normal walking gait (running can be different) the parameters dictate heel strike it does not have to be a long latent heavy impact period.  Heel strike and impact should not be accentuated, heavy or prolonged.  Many gait pathologies can occur when it is significant because the forces move up into the organism, for example increased knee extension or longer duration of the rear foot inversion phase and thus supination foot phase.  Rather, begin to focus the thought more on heel contact (sort of a quick kiss as opposed to a long drawn out French-kiss necking session) and the subsequent and immediate soft gradual transition into the full foot loading phases.  In otherwords, finesse the heel contact phase. Perhaps if runners had always looked at heel strike this way we would never have seen such a major intellectual epiphany towards midfoot and forefoot strike being the answer and heel strike being the black plague of all things gait/running related. So, at this moment, while it is still fresh in your mind, get up from your chair and walk and feel the difference between kissing the heel on the ground and a major heel-floor make-out session ! You may immediately note the woes of your ways. You may begin to make walking a more conscious finessed movement while in the process begin to note that walking should be soft and fluid, almost an art form or conscious zen-like meditative act where constant awareness is key. 

For those new to gait talk and running, remember that walking gait does dictate this heel strike phase where as in proper running this phase is absent when unshod and most of the research is leaning towards this absence when shod as well (hence the minimialist shoe trend of today).

To put a cap on this talk, we would like to say that these are our kinda people ! Geeks rule !  (but then there are these kinds of people here (Las Vegas high heel shoe race, for those of you who don’t want to link elsewhere) that need to have their heads checked a little…… have they not hear Dr. B’s lecture on heels ?)

Shawn and Ivo…… The Gait Geeks, the guys you beat up in grade school, and now the kinds of geeks you gravitate to for intellectual stimulation. How ironic huh ? Who’s your daddy now !

Gait arm swing..... more on Dr. Carrick and Sid Crosby→

more on Dr. Carrick

you will see here some clues into what Dr. Carrick (One of Dr Ivo’s and Dr Shawn’s Mentors), and what we, look for in gait and arm swing etc.  It is so much more than telling someone to swing an arm more, or turn a foot in.  It is about the brain and global function. Remember Dr Ivo’s Neuromechanics lecture on the central integrated state? (if not click here).  That is what this is all about.

Neuromechanics Weekly:

What does the Reticular Formation have to do with gait?

Have you ever worn flip flops? What do you need to do to keep them on? Clench (flex) your toes (specifically your flexor digitorum and flexor hallicus longus). What does that have to do with gait?

Take off your shoes (hopefully you showered); reach inside (unless there is something growing in there) and pull out the removable insole.  Look at it. See those toe marks? Looks like someone has been clenching their toes again! So what?

This video exemplifies why flexor dominance (you have heard us say it many times) inhibits extensor activity. The upper part of the reticular formation fires the extensors, but the lower part inhibits them AND the corticospinal tract (basically the motor pathway you use to fire most of your voluntary flexors) stimulates the lower reticular formation (which inhibits the extensors). Many pathologies are because of flexor activity, and his is one of the pathways that’s facilitates that pathway. The key to fixing many problems? Fire the extensors! (And stay out of flip flops)

The Gait Guys….figuring it out and explaining it to you in terms that make sense. And no, we do not own any flip flops….

The awkward runner ?: Gait Ataxia, another cause.→

Vitamin B12 deficiency: Another cause of Gait Ataxia.

Here is where our clinical background gives us another slight edge on those in the gait and movement fields. Once again we need to bring to the table another cause of gait problems.  This problem can manifest as a gait, running or simply a mild impairment of muscular coordination patterns.  There are so many people out there these days providing “care” to athletes and those that want to stay physically fit. Many of these care givers however are not in the medical field. They might be a coach, trainer, massage therapist, physical therapist, or God forbid someone you are taking advice from over the internet. The problem in giving health advice or treatment is that it is easy to do and often, if you are without a medical license, fraught with the “you cannot be aware of something that you do not know exists”.  So, if you are one of those who trains or coaches people, offers nutritional advice, stretches, massages, “activates” or uses other means without a medical license, you had best be aware that you could be missing things.  And, even if you do have a license, failure to get results is sometimes a result of something being missed diagnostically, not a failure to treat enough or not using the right techniques or therapy. This is not a dig at anyone or their passion, it is just a fact, without a medical background you just might not be exposed to the gamut of things to be aware of.  Thus, it is quite possible that “interventions” are not working because other things are lurking below the surface, things one just might not be aware of. On this note, It is never a bad idea to ask your athlete if they have had some blood work and chemistry workups in the last 12 months, especially if they are not progressing or are having some of the early subtle signs or symptoms of something bigger lurking systemically. Read on.

You will recall from our last talk on movement impairments from organic or systemic nutritional complications (Nov 10th, Gluten Gait Ataxia) that there are several metabolically driven gait and ataxia disorders. The one we are going to talk about today is Vitamin B12 deficiency ataxia (we are going to downplay the pernicious anemia thing for now to stay focused).

You will recall that the definition of ataxia is pretty broad.  Ataxia refers to an inability to coordinate bodily movements, especially movements of the muscles. Thus ataxia can manifest as a possible aberrant motor pattern, lack of coordination or subtle gait impairments such as early balance difficulties.

Vitamin B12 (aka cobalamin) is a water soluble vitamin that has a paramount role in the normal function of the central nervous system and blood formation. It is one of 8 B vitamins. Vit B12 deficiency is nothing to shrug off.  In its most severe unaddressed form it can potentially cause irreversible central nervous system damage (for you doctor-types out there you will fondly recall the long lectures on SCD (subacute combined degeneration of the spinal cord and CNS) from your favorite neurophysiology professors).  At subacute B12 levels softer symptoms can range from fatigue, depression, dizziness, memory loss, confusion, anxiety and other neurocognitive problems as well as altered executive function, ataxia (unsteady gait, balance impairment) peripheral limb or circumoral numbness or tingling.  The vagueness of these symptoms often lead to untimely diagnosis.   

Vitamin B12 occurs naturally in most animal products, but if you are one of millions of people who cannot absorb B12 efficiently, then you can begin experiencing symptoms of vitamin B12 deficiency.  And yes, to remind you once again, the symptoms are soft and vague at the start.  They are vague because it takes time for gradual degradation of the nerve’s myelin sheath, the place where Vit B12 has its impact. It is this myelin, the conductive coating on a nerve, that is necessary for accurate and timely communication between the central nervous system and muscles and organs.  And it is here that gait ataxia truly begins.  The nerves of your spinal cord rely on a steady in and outflow of information from your nerve sensors throughout your body.  Messages to and from the nerves in your limbs are conducted along the spinal cord (particuularly in the spino cerebellar and dorsal column tracts: See Dr Ivo’s neuromechanics lectures for a review of these here ) and to the brain, thus controlling gross and fine motor tasks such as running, walking, dancing, climbing, skipping, or tapping your feet.  Nerve damage causes these signals to become misinterpreted, resulting in poor coordination, or gait ataxia.

Here are some signs and symptoms of gait ataxia:

• Unsteady gait, difficulty walking without stumbling
• Difficulty staying balanced on one leg
• Trembling awkward movements, clumsiness
• Muscular weakness in the legs and arms
• impaired motor tasks
• Spasticity
• Hypotension (low blood pressure)
• Vision problems
• Numbness / tingling; particularly around the mouth

So that is our little talk on gait ataxia and its relation to Vit B12.  It is a quite in-depth topic to be honest but we want to keep this concise.  In terms of recommendations, we are not going to make any here today.  The recommended daily allowances are easy to find on the internet.  Two things you can do,  you should improve your diet (we all can) and get yearly blood work studies.  If you are vegan (unless you are a lacto-ovo vegetarian) or do not consume much in the way of animal based food products you need to consider B12 supplementation (that or start eating termites - B12 rich !).  You should also be aware that there are many things that can alter Vit B12 absorption /integration such as birth control pills, alcohol consumption, nicotine, medications, antibiotics and many others. These are consumables that increase your risk of B12 problems and thus risk for gait ataxia and the other B12 related issues.  Most of the time, ataxia is a difficult diagnosis to make (unless a copious single event of alcohol consumption at the local pub is the culprit). 

Bottom line.  There is so much more to Vitamin B12 deficiency but this was not meant to be that forum.  Ataxia and gait alterations are nothing to dismiss, especially in the elderly.  There are many causes of ataxia and this is just another that we wanted to bring to light.  The nervous system and muscular systems have some definite source needs and Vit B12 is one of them.  Without the right fuel these systems will begin to show impairments, soft impairments at first which could be the difference in a high level athlete’s performance.  If your parents, patients, athletes or those you know are expressing some vague and subtle symptoms, educate them. Better yet, send them off to their doctor if symptoms persist, rather than handing them a bottle of Gatorade and casually telling them they are probably just dehydrated, anemic from low iron or low on electrolytes …. as it so often occurs.

Shawn and Ivo, The Gait Doctors

The Week in Gait Newsletter.

On Sunday over 700 people received our weekly newsletter “The Week in Gait”.

This newsletter is for those who have emailed us requesting to be signed up or have opted in through our Constant contact app on our Facebook page (that is the easiest way for you and for us).

If you want exclusive content not on the blog or facebook, if you want first hand notice of a lecture we are giving, a magazine article in the works, an early bird DVD release (yup, on their way in early 2012), or just want a nice recap of the best blog posts of the week with some extra exclusive commentary from Shawn and Ivo……. then you want to be receiving our weekly newsletter….. The Week in Gait.

Sign up today or email us. The newsletter will go out every weekend, at least we anticipate that being the case.

Shawn and Ivo

Watch more videos on Flotrack

Lauren Fleshman on her injuries. Biomechanics you say ?!

We should have called this blog series, Saving Lauren Fleshman.

She seems like a real smart gal. It is not her job to figure this stuff out though so we do not fault her in the least.  We just hope she or her doctors look at our blog posts and youtube videos. Anyone want to nudge her in that direction ?

Foot Scan: A Case Study.

What can we glean about this person from this pressure sensitive foot scan ? Remember, no examination possible here so lets see what we can assume is happening.  These kinds of mental aerobics help keep us clinically sharp and help us pick out subtle patterns in someone gait when we do gait assessments …. so that we can prove them or disprove them on the table during our exam. Remember, for this case, the person is standing, not moving through the gait cycle like in a normal pedograph mapping or F-Scan (hence making an orthotic or true and accurate assumptions from this type of static scan would be really silly …  but alot of people and companies do it ! Sadly.) We are presenting this case for the means of mental stimulation and observation only.

1. Increased foot pressures on the lateral aspect of the right foot. One possibility here is that there could be a short right leg here (anatomic or functional) and the person is supinating to lengthen the limb.  Remember, supination creates a lift in the talus height because the foot is in relative plantarflexion, adduction and inversion and the limb is moving into external rotation, this will all increase the length from foot to pelvis. In contrast the flat foot has internally spun the limb and the foot is dorsiflexed, abducted and everted.
2. Both feet  have reduced medial plantar pressures but remember this is a person standing and not moving through the gait cycle so do not make too many functional assumptions.  Some people who have weaker feet and slightly incompetent arches will often stand on the outsides of the feet because the foot is more supinated and rigid, hence more stable from a joint “lock out” perspective.  People with weakness will always opt for FORM closure (closed packed joint) over FORCE closure (muscular joint compression stabilized joint).
3. Increased flexor hallucis brevis and longus (FHL and FHB) use of the big toe on the right. This appears to be balanced.  If FHB dominated the red would be more proximal on the digit. If FHL were more dominant, the red would only be at the tip.  This imbalance is easy to pick out on a pedograph and in callus patterns on the big toe (do not mistake this callus pattern we are talking about with a medial pinch callus on the inner edge of the big toe, this is from something different …  that is another post another day). In contrast, this person has little left FHL or FHB use.  This doesn’t bother us too much, but the increased right lateral foot pressures and the increased forward forefoot pressures (more RED on more of the toes on the right) tells us this person is supinating the foot and increasing overall plantar grip-type pressures.  Remember Newtons 3rd Law…… for every force there is an equal and opposite reactive force, so more plantar pressure means more upward force into the limb. This could possibly be to help increase more gluteal activity. This leads us to #4.
4. Newton’s 3rd Law. The increased right plantar and supinatory pressures are going to likely activate more gluteal function.  Get up from your chair and take a few steps.  And when you do, push your right foot into the ground more firmly than normal. Do you feel the glute function increase ? You should. Especially note the gluteus medius drive the pelvis medially (this is one of our tricks to help people arrest the frontal plane drift and reduce cross over gait in running). 
5. We would have normally said that the increased right toe pressures (RED) would have meant more forefoot loading in this stance but we do not see a reduced heel pressure so that means they are actively using more flexor dominated strategy. Increased digit flexion will help to drive the arch upwards from the bottom (as opposed driving the arch up from lift (tibialis anterior & posterior).
6. Otherwise this is a pretty normal looking foot.  IF you measure the width of the foot at the narrowest part of the waist you will see that the right is a little wider (and there is more blue). This could mean that this foot is a little weaker intrinsically and could be one that pronates more in gait or is just a little more pronated here (hence the supination evidence as layed out above).  Thus, this could give us good reason to assume the right RED plantar increases …  meaning, this person is working harder on the right to work out and avoid pronating.  Everything we said above seems to fit this ASSUMPTION. 

Hope this was a nice little exercise in observation and mental juggling.

By the way, Juggling is a great mental exercise….. A Princeton researcher, Les Fehme suggested we can optimize our overall performance in life by broadening our focus. Juggling is one excellent way to do that. He claims most people have a narrow focus, a lack of awareness of their own body sensations or emotions. A recent CNN report suggested juggling increases the amount of grey matter in areas of the brain that process and store visual information, proving what was not thought possible – that new stimuli can alter the brain’s structure. A comparison of brain-imaging scans of non-jugglers and other volunteers before they learned to juggle and three months later, revealed an increase in grey matter in certain areas of the newly trained jugglers’ brains.

And so … thanks for juggling with us today.  We hope you did not choose to use chainsaws or Ron Popeil knives (“Wait, there’s more! We’re going to double your order!”). Wanna get a little crazy driving more brain grey matter integration ? Try running while juggling, if you dare ! We recently heard of a guy that broke a record running a recent marathon juggling 3 balls the entire time.  Who has time for this shenanigans ?! We have troubles getting our laundry done.

Ivo and Shawn ….. your jugging court jesters. Jester, hmmmm …  perhaps a good label for us.  Sounds like it was a fun job.

(define: A jester, joker, jokester, fool, wit-cracker, prankster, or buffoon was a person employed to tell jokes and provide general entertainment. Jesters are stereotypically thought to have worn brightly colored clothes and eccentric hats in a motley pattern. Other things distinctive about the jester were his laughter and his mock sceptre, known as a bauble or marotte.)