The Windmill Pitch: Fastpitch Softball. More proof that arm swing and opposite leg swing are powerfully coordinated and neurologically paired.

Step length and power can affect opposite arm power and speed.

You have heard us talk often about opposite arm and leg swing pairing and how important they are from a neurological coordination issue. We have also talked about energy conservation and transmission in prior blog posts when it comes to arm swing. Good arm swing will lead to energy conservation.  A reduction in arm swing leads to a poor gait economy.  Check out this study here and the statistics. 

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 still requires 12 % more metabolic energy.  Among measures of gait mechanics, vertical ground reactive moments are most affected by arm swinging and increased by 63% without arm swing.”

* type in “arm swing” into our blog SEARCH box and you will see 14 articles we have written on arm swing in human locomotion.

Gait is in every sport, just about.  Here we see a beautiful depiction of the opposite arm and leg pairing neuro-biomechanically, albeit not gait here it is still in her movement.  The larger a first step , whether the pitcher is a overhead hardball thrower or underarm fastball pitcher, the concept remains preserved.  I was a pitcher for over 10 years in the Ontario Fastball league back in Canada when I was a youth and teenager.  I was not a big speed pitcher, but what I had troubles coming up with in speed I was able to make up in putting “junk” on the ball.  My first step was large, and the larger the left step length (as seen in this video here), the more pelvic obliquity that could be achieved, which in turn enabled an opposite “anti-phase” rotation of the shoulder girdle.  When you add increased shoulder girdle obliquity with full arm rotation speed losses can be contained and limited.  Hypothetically, ball speed in a smaller player with a large first step can be heightened to the point of a that of a larger stronger pitcher with a smaller step.

Here you can see a great demonstration of this large step length the video.  They are using the tilt board to facilitate a faster downward plantarflexion of the right foot to drive a larger faster left step. It is the same principle as if you stepped off a curb or into a hole unexpectedly, the body’s natural reaction is to step out quickly with the other limb to catch the body’s forward fall. The board is used to achieve the same result with control. This is why you will see pitchers dig out a trench immediately in front of the pitchers rubber, to create this same plantarflexion drop of the right foot (in this case, the right foot for a right handed pitcher).  The deeper the trench, the more aggressive that left step.

Shawn and Ivo………..digging deep trenches today…….. and finding gait theory everywhere, even in fastball.

http://youtu.be/QzojfAUcGEI

http://youtu.be/0OA6RfTre6M

Have you ever wondered why people who walk together quickly synchronize their gaits ?

From healthy heart cells that synchronize to a single beat, to women in school dormitories or work places who synchronize their menstrual cycles, to fireflies who begin blinking in synchrony when they all perch in the same tree synchronization is something that is abundant in nature.  It is no wonder that we find synchronicity in one of our most primitive and frequent motor patterns, walking together with someone shows the same synchronicity phenomenon.

Hold the hand of your favorite person and go for a walk. Within a few strides your gaits will synchronize. Is it because it is easier ? Is it because when synchronized the arm swings will match thus making it easier and more effortless to hold hands ?  Does the same effect occur
if you are not holding hands ? Studies have concluded that although it does not happen all of the time, they found it occurs in almost 50% of the walking trials even among couples who do not usually walk together. This is far too high a percentage to not make it a statistically significant finding.

The synchronization between walking partners is more complex than it seems on the surface.  There are two types of synchronization, in-phase (both person’s right foot move forward at the same time) and out-of-phase synchronization (where the right foot moves forward with the partners left foot).  You can see in the video above that the couple has subconsciously fallen into an Out-of-Phase synchronization, then after the tide splash that throws them off within just a few steps they fall right back into Out-of-Phase synchronization and hold it in that state.  There are multiple factors and communication mechanisms occurring. There are auditory mechanisms in play such as the sound of the other persons foot fall.  There are even visual mechanisms through peripherally seeing your partners arm swing and foot fall which encourages the imitation synchronization. However, the strongest in-phase synchrony occurred in the presence of tactile feedback meaning hand holding or embracing each others waist from behind, which couples often do when walking more slowly, seem to create a stronger synchrony.  When this tactile component is engaged between two walkers it is plausible that the upper and lower limbs move more freely when paired up, particularly with arm swing.

What is thought to happen is that one partner dominates the lead in the gait, just as in dancing, one person is the leader and the other is the follower. The lead partner’s lower limbs determine the movement of their arms, which in turn when holding hands, sets the arm movement pattern in the partner then determining the leg swing and stance phases. Thus, synchrony is achieved. 

However, it is important to note that many of the studies were clear to mention that even in non-tactile cases, many of the gaits of two people walking together are synchronized. This was likely due to the visual and auditory parameters however height, leg length cadence etc could also play into those successful non-tactile synchrony cases.

These are interesting findings at 50% because it is very unlikely that any two people are of the same height, leg length, cadence, stride and step length.  These are all parameters that are likely to change the likelihood of gait synchrony.  Zivotofsky found that “even in the absence of visual or auditory communication, couples also frequently walked in synchrony while 180 degrees out-of-phase, likely using different feedback mechanisms”. The studies below discuss many issues of this synchrony but it is perhaps most significant in clinical rehabilitation cases or in early or moderately advanced movement impairment disorders and diseases these findings may partially explain how patients can enhance their gait function when they walk with a partner or therapist.  It is in these movement impairment syndromes and diseases where the central processing and Central Pattern Generators (CPG’s) are diseased leaving them with the need for other cues such as those discussed here today, auditory, visual and tactile. 

You may have read our previous blog articles on arm swing and how intimately they are anti-phasically (opposite) paired with lower limb swing.  But today’s blog post article took limb swing to another level.  Stay tuned for more on arm and leg swing in human movement.  If you wish to read our other works on arm and leg swing and their deeper effects on gait, go to our blog www.thegaitguys.tumblr.com and enter the words “arm swing” into the SEARCH box.

Shawn and Ivo…….. taking gait far beyond what you learned about it in school.
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References used:


J Neuroengineering Rehabil.
2007; 4: 28. The sensory feedback mechanisms enabling couples to walk synchronously. An initial investigation.  Ari Z Zivotofsky and Jeffrey M Hausdorff  Published online 2007 August 8. doi:  10.1186/1743-0003-4-28

Hum Mov Sci. 2012 Jun 22. [Epub ahead of print] Modality-specific communication enabling gait synchronization during over-ground side-by-side walking. Zivotofsky AZ, Gruendlinger L, Hausdorff JM.Gonda Brain Research Center, Bar-Ilan University, Ramat-Gan 52900, Israel.

Gait Problem ? But where is the problem ? A case of failed single leg stance in a runner during the “3 Second Gait Challenge”.

Remember, what you see is not the problem most of the time.
You have heard it from us over and over again. What you are seeing in someone’s gait or running, the thing that does not look right, is their strategy to cope with the body parts that are dysfunctional. You are quite often not seeing what is wrong.
For example, here during our “3 Second Gait Challenge” this gentleman shows a solid left stance phase of gait. At times it is so solid and calm that it looks like we still-framed the video. The right side is another matter. During right stance there is excessive “checking” of the frontal plane (side to side) at the ankle. You also clearly see him using the right arm as a ballast moving it out to the right during right stance phase to help offset and dampen the frontal plane challenges.
Now going back to our initial thesis (“Remember, what you see is not the problem most of the time.”) surely you will agree that what you are seeing that right arm doing is probably not the problem here. Correct ? 
Now, this is a patient of ours, so we know what is wrong with him.  But from an outsider looking in, the problem in this case is more likely in the right lower limb, but you cannot see what is wrong with it. So remember, what you see is frequently not the problem, rather it is a compensation strategy. This gentleman’s problem is coming from his right lower abdominal functional impairment (specificially the lower transverse abdominus and internal abdominal oblique functional weaknesses, we know because we  clinically muscle assessed him for strength, skill, and motor patterns in our office.) These muscles were clearly neurologically inhibited and weak and the motor pattern he has laid down is many years in the making, driving a deeply seated compensation pattern.  Basically, he cannot stabilize his torso on the pelvis-hip during single leg stance. This lets the pelvis drift to the right. In this case it was not gluteus medius weakness allowing for the drift, which is more common. The torso is weak on the right side making it difficult to stabilize right lateral torso movement so he cheats by moving his torso to the left (which you can see) but does so ineffectively and thus needs to use the right arm to “check” the poor strategy.  His Rolling patterns were clearly disfuctional however even after correcting them he still had the gait neurologic pattern as his default,  hence gait retraining is necessary in this and all cases. We do many other functional assessments, methods we have developed and they all clearly directed and confirmed the diagnosis.  Just remember, if you fix a person’s movement patterns but then do not fix the repetitive gait pattern they have been using then their gait is cycling the problems right back into the person and you are wasting your, and their, time. 

Additionally, It would be easy to say that this gentleman has a proprioceptive deficit and that he needs to do some balance work on a Bosu ball or  tilt board.  But that is “so last year” thinking. If someone is having troubles standing and balancing on a stable concrete floor why in the world would you make his stance surface training even more unstable ?  This again is just not wise thinking. You don’t first learn to drive on the freeway, you start in a parking lot or back street where you can learn skills at a slow speed first. Conquer stability on a stable surface, then progress them to a more unstable surface.

Today we showed you a small diamond in our assessments. The “3 second gait challenge”.  This one is a keeper for us.  As we always say “Speed kills”. And in gait speed also is a disguise, it blends and blurs the deficits and challenges.  Slow your clients done to 3-4 seconds and watch what jumps out at you !  (did you read our blog post on Speed and Gait deficits ? Here is the link.) Speed is the devil when it comes to gait. At a normal walking pace and running pace these deficits were not perceptible, because speed in the sagittal plane (moving forward) reduced the lateral challenges. Speed blurs, speed blends and speed kills.

We continue to ask “Of all the functional movement courses being offered out there now, why do they not get into functional gait screening?”  We think we have the answer.  It is likely because this stuff is difficult, it is because it takes a deep knowledge base of whole body biomechanics/functional anatomy (from arm swing to big toe function) and it is because what you see in someone’s gait is very often not the problem.  A deep and broad understanding of human gait is not something you can pick up in a single weekend seminar nor can it be something done simply by a “check off” sheet.  This is complicated stuff, our 700+ blog posts with 230 in the draft folder plus 90 YouTube videos proves that there is great depth to gait and proves how complex it can be. But, if you have been with us for awhile and continue to work at this stuff you are likely getting better and better at this gait stuff. Do not give up. This is a worthwhile journey.

We are The Gait Guys. Shawn and Ivo.

Providing a stable surface for your knowledge base!

* remember: by clicking on the YOUTUBE logo in the lower right you will be immediately linked to a larger viewing screen on youtube.

This is a video case of a triathlete who presented with left calf pain and right quadriceps leg pain after months of training. In the video we discuss altered ankle rocker (dorsiflexion), lower crossed syndrome, altered arm swing patterning, unilateral quadriceps tightness and several other functional gait pathologies with this case.

Video Gait Case: It is Neuromechanics Wednesday.

* Remember: you can always click on the YOUTUBE logo in the bottom right corner of the video to be hyperlinked to a blown up version of the video on youtube.  Just remember to read what we have written here as well. 

Here we present a video case of a client with advancing spinal myelopathy with characteristics of Trendelenburg gait pathology. Be patient with the first few slides, we have to set up and teach about the important issues regarding the topic and case otherwise some folks will get lost.  There is much to this case. There is evidence of balance issues (dorsal column disease), limb circumduction, 5 point turning strategy (abnormal), pathologic arm swing changes and a few other issues to observe. If you are looking for a great gait case that covers several layers, this is a good one. Be sure to check our our blog, youtube channel and website for other great videos and teaching cases.

Arm swing in gait and running. Why it is crucial, and why it must be symmetrical.

It becomes clear that once you get the amazing feats seen in this video out of your head, and begin to watch just the variable use of the arms that you will begin to appreciate the amazing need for arm swing and function in movement.

We have written many articles on arm swing and its vital importance in gait and running. Have you missed all these articles ?  If so, go to our blog main page, type in “arm swing” in the search box and you will have a solid morning of readings at your fingertips.  We are still not done writing about this most commonly forgotten and overlooked aspect of gait and running analysis, and we probably never will be done.  Why is no one else focusing on it ?  We think it is because they do not see or understand its critical importance.

Without the presence and use of the arms in motion things like acceleration, deceleration, directional change, balance and many other critical components of body motion are not possible.

What is perhaps equally 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.”

is that as spine pain presents, the shoulder and pelvic girdle anti-phase begins to move into a more in-phase favor.  Meaning that the differential between the upper torso twist and pelvic twist is reduced. As spine pain presents, the free flowing pendulum motions of the upper and lower limbs becomes reduced to dampen the torsional “wringing” on the spine. When this anti-phase is reduced then arm swing should be reduced. The central neural processing mechanisms do this to reduce spinal twisting, because with reduced twist means reduced spinal motor unit compression and thus hopefully less pain. (Yes, for you uber biomechanics geeks out there, reduced spine compression means increased shear forces which are favorite topics of many of our prior University instructors, like Dr. Stuart McGill). The consequence to this reduced spinal rotation is reduced limb swing.  And 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 still requires 12 % more metabolic energy.  Among measures of gait mechanics, vertical ground reactive moments are most affected by arm swinging and increased by 63% without arm swing.”

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.

In past articles we have carried these thoughts into historical functional needs of man such as carrying spears and of modern day man in carrying briefcases.   Today we show a great high functioning video of another parkour practitioner.  Parkour is a physical discipline and non-competitive sport which focuses on efficient movement around obstacles.  Watch closely the use of the arms. The need for arm use in jumping, in balance, in acceleration etc. It becomes clear that once you get the amazing feats seen in this video out of your head, and begin to watch just the use of the arms that you will begin to appreciate the amazing need for arm swing and function in movement.

There is a reason that in our practices we treat contralateral upper and lower limbs so much.  Because if you are paying attention, these in combination with the unilateral loss of spinal rotation are the things that need attention. 

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, 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 have to 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 40 years of orthopedics, neurology, biomechanics and gait studies to get to the bottom of things.

Hey Check it out! John Wayne has either a Left short leg or a weak left Gluteus medius and a compensatory increased arm swing on the Right ! Watch for the lean to the left on Left stance phase and the arm swing to pull him through. WE guess even the Duke needs a hand sometimes !

The “Dukes” of Gait Shawn and Ivo