Whole-body coordination patterns may become partitioned in particular ways as a function of task requirements

Just some more thoughts for those who insist on coaching arm swing changes.

"Whole-body coordination patterns may become partitioned in particular ways as a function of task requirements.”

Toddlers actively reorganize their whole body coordination to maintain walking stability while carrying an object. Hsu WH1, Miranda DL2, Chistolini TL3, Goldfield EC4. Gait Posture. 2016 Oct;50:75-81

Today we seem to be going back to dual-tasking again, in this case utilizing the arms as balance assistance devices, amongst their other functions. However, we all know that walking with a hand in a pocket, or carrying something alters our ability to maximize their ballast-like function. Balanced walking involves freely swinging the limbs in pendullar motion. Changes in arm swing will change gait economy and efficiency. We have all run with a water bottle or bag/briefcase and know how that changes the symmetry and fluidity of our gait.

Today's research piece discusses toddlers and their function as they carry objects. "children immediately begin to carry objects as soon as they can walk. One possibility for this early skill development is that whole body coordination during walking may be re-organized into loosely coupled collections of body parts, allowing children to use their arms to perform one function, while the legs perform another. Therefore, this study examines: 1) how carrying an object affects the coordination of the arms and legs during walking, and 2) if carrying an object influences stride length and width." -Hsu et al.In this study of 10 toddlers with 3-12 months of walking experience were recruited to walk barefoot while carrying or not carrying a small toy. "Stride length, width, speed, and continuous relative phase (CRP) of the hips and of the shoulders were compared between carrying conditions. While both arms and legs demonstrated destabilization and stabilization throughout the gait cycle, the arms showed a reduction in intra-subject coordination variability in response to carrying an object. Carrying an object may modify the function of the arms from swinging for balance to maintaining hold of an object. The observed period-dependent changes of the inter-limb coordination of the hips and of the shoulders also support this interpretation. Overall, these findings support the view that whole-body coordination patterns may become partitioned in particular ways as a function of task requirements." -Hsu et al.

So once again we will say it, if you are coaching the arm swing YOU want, because you do not like what you see in your client, or if you think you are helping your client get more out of their body in terms of speed, power, efficiency or anything of the sort, know that there is a higher, smarter program running the show. And that program in the client’s CNS is smarter than you when it comes to what they need for whole-body coordination pattern generation.

Your center of mass in relation to foot strike position.

For those arm swing/pulsers/ COM and head over foot folks consider some more research below.
Let the CNS drive the show, it is what it is there for . . . The leg motor patterns are dominant, the arms are passive and "shape" and influence the leg swing as a balance and ballast effect. As we discuss in an upcoming podcast, to cross the arms in a pumping motion across the midline of the body means one has to have compromised scapular mechanics (mostly protraction) to afford that much humeral adduction. This means we are forcing thoracic rotation as well. This means we are reversing what we know is more true, that "arm motion is driven passively by rotation of the thorax (Pontzer et al., 2009), an idea which is supported by shoulder muscle EMG data" (and not thoracic rotation by arm swing). Why would we try to create more unnatural axial spin through the spine when we are actually trying to move forward in the sagittal plane? Why would we try to force more rotation through the spine when the function of the thoracopelvic canister (ie. the core) is to stabilize rotational /angluar momentum? Hmmmm, things to ponder.

"Previous modelling studies have clearly shown that motion of the arms effectively counterbalances the angular momentum of the lower extremities during running (Hamner & Delp, 2013; Hamner et al., 2010). It has further been suggested that arm motion is driven passively by rotation of the thorax (Pontzer et al., 2009), an idea which is supported by shoulder muscle EMG data, consistent with the shoulders as spring-like linkages (Ballesteros, Buchthal, & Rosenfalck, 1965). Our data are con- sistent with this idea, showing motion of the thorax to be in the opposite direction to that of the swinging leg. Pontzer et al. (2009) also suggested that motion of the thorax is driven passively by motion of the pelvis. However, our data shows that the thorax reaches its peak angular velocity earlier than the pelvis, indicating that thorax motion is not completely passively driven by pelvic movements."

-S.J. Preece et al. / Human Movement Science 45 (2016) 110–118

Dominance of the lumbosacral girdle over the cervicothoracic is probably preserved in humans

. . . dominance of the lumbosacral girdle over the cervicothoracic is probably preserved in humans
This suggests that arm swing is, to a notable degree, subservient to leg swing.

Research thus far has strongly suggested two pieces to arm swing, a passive and an active swing component. Without muscle activity, passive swing amplitude and relative phase decrease significantly. As phase decreases, it is referred to as in-phase swing pattern of the arms. The Goudriaan et al paper referenced below concluded that "muscle activity is needed to increase arm swing amplitude and modify relative phase during human walking to obtain an out-phase movement relative to the legs."
But it is more complicated that this . . . .

Research continues to suggest that interlimb coordination is achieved at the brainstem and cortical level, which this study suggests as to why we can dual task and walk with something in our hands, carry objects and even walk and run with said objects and changes in our gait . . . . because, the program is running off a top down neurologic mediated process with predictable, economically CPGs(central pattern generator) in place.
"The coordination of arm and leg movements takes the form of an in-phase relationship between diagonal limbs [64]. The dominance of the lumbosacral girdle over the cervicothoracic is probably preserved in humans as well. For example, Sakamoto et al. [65] showed that during combined arm and leg cycling, the cadence of the arms was significantly altered when leg cycling cadence was changed. The opposite, however, was not true, i.e. the arms did not affect the leg cadence."-Preece et al.

Human Movement Science 45 (2016) 110–118
The coordinated movement of the spine and pelvis during
running
Stephen J. Preece, Duncan Mason, Christopher Bramah
School of Health Sciences, University of Salford, Salford, Manchester M6 6PU, United Kingdom

Gait Posture. 2014 Jun;40(2):321-6. doi: 10.1016/j.gaitpost.2014.04.204. Epub 2014 May 6.
Arm swing in human walking: what is their drive? Goudriaan M1, Jonkers I2, van Dieen JH3, Bruijn SM4.

Coordination of leg swing, thorax rotations, and pelvis rotations during gait: The organisation of total body angular momentum

"In walking faster than 3 km/h, transverse pelvic rotation lengthens the step (“pelvic step”).
The shift in pelvis–thorax coordination from in-phase to out of phase with increasing velocity was found to depend on the pelvis beginning to move in-phase with the femur, while the thorax continued to counter rotate with respect to the femur. "

We are always trying to bring greater understanding to this group at TGG regarding gait mechanics. One must understand the implications of rotational work, and anti-rotational work on the phasic and antiphasic nature of the thorax and the pelvis. We have talked about becoming more phasic when there is spine pain. With today's study, we delve just al little deeper, particularly noting how the pelvis and the femur moving together first, before that is offset by the antiphasic nature of the thorax at higher speeds of gait.
This article uses the terms in phase and out of phase. We have learned over time that those terms to relate more so the description of how the limbs are, or are not, pairing up when a couple is walking together. None the less, the reader here should understand how they are referring to out of phase as antiphasic.

http://www.sciencedirect.com/…/article/pii/S096663620700135X

 

How the CNS adapts. Exploratory testing of the ground.

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

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

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

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

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

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

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

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

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

Screen Shot 2018-01-25 at 12.27.39 PM.png

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

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

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

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

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


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

 

Podcast 132: Arm swing, gait retraining and steroids.

Key Tag words:  thegaitguys, gait, gait analysis, arm swing, cortisone shots, corticosteroids, leg swing, running injuries

Links to find the podcast:

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

http://traffic.libsyn.com/thegaitguys/pod_132f.mp3

http://thegaitguys.libsyn.com/podcast-132-arm-swing-gait-retraining-and-steroids

Libsyn Directory URL: http://directory.libsyn.com/episode/index/id/6087848

Our Websites:
www.thegaitguys.com

summitchiroandrehab.com doctorallen.co shawnallen.net

Our website is all you need to remember. Everything you want, need and wish for is right there on the site.
Interested in our stuff ? Want to buy some of our lectures or our National Shoe Fit program? Click here (thegaitguys.com or thegaitguys.tumblr.com) and you will come to our websites. In the tabs, you will find tabs for STORE, SEMINARS, BOOK etc. We also lecture every 3rd Wednesday of the month on onlineCE.com. We have an extensive catalogued library of our courses there, you can take them any time for a nominal fee (~$20).

Our podcast is on iTunes and just about every other podcast harbor site, just google "the gait guys podcast", you will find us.

Show Notes:

Corticosteriods and healing
https://www.eurekalert.org/pub_releases/2017-10/lu-cah101717.php

-steroid full text: https://www.nature.com/articles/s41598-017-12657-0

Can gait retraining prevent injuries ?
https://youtu.be/s8Og2bYsPTM

Exp Gerontol. 2002 May;37(5):615-27.
The reserve-capacity hypothesis: evolutionary origins and modern implications of the trade-off between tumor-suppression and tissue-repair.
Weinstein BS1, Ciszek D.

Arm swing:
Do you remember what Anti-phasic gait is ? If not, this study might not mean much to you. But we have written gobs about it on our blog over the years.

This study looked at "how arm swing could influence the lumbar spine and hip joint forces and motions during walking."

But, we have more to say on this, so, see you on the blog here . . .
https://www.thegaitguys.com/thedailyblog/2017/10/16/arm-swing-and-dynamic-stability-of-the-system

Effect of arm swinging on lumbar spine and hip joint forces
Lorenza Angelini et al. Journal of Biomechanics, Sept 2017
http://www.sciencedirect.com/…/article/pii/S0021929017304670

Arm Swing and dynamic stability of the system.

Screen Shot 2017-10-16 at 1.33.03 PM.png

We have discussed the arm swing issue so many times over the years that we have lost count. By many sources, arm swing is a product of lower limb action and a product of the effective, or ineffective, relationship between the shoulder "girdle" (maybe thoracic rotation component) and the pelvic girdle (lumbopelvic rhythm) during gait.  This is the concept of phasic and anti-phasic limb swing. If you want to dive into that, and you should if you are unfamiliar with the concept, you can look it up on our blog using the search box.  We are not to forget that the arms, and thus arm swing, is a major factor in maintaining balance. We have used the term "ballast" many times to describe the effects of arm swing, rotation, abduction, circumduction etc on assisting balance maintenance of the body during various locomotion strategies. These are largely subconscious actions, hence why we agree with the research suggesting that arm swing is secondary, compensatory, and takes its queues off of the activity of the lower limb motor actions. In essence, arm swing variants are necessary compensations to assist in maintaining things like balance, center of pressure, equilibrium and the like. 

In this recent 2017 study, we have another suggesting arm swings function in assisting, even improving, dynamic stability. We are reminded of MdGill's suggestion, and the concepts of phasic and antiphasic torso-pelvis counter rotational movements, of how spinal loads can be affected by changes or differences in arm position.  Even arm position changes in sitting and standing can alter spinal loads, so during movement it is a virtual guarantee. 

This study looked at "how arm swing could influence the lumbar spine and hip joint forces and motions during walking." In this study, the researchers had each subject perform walking with different arm swing amplitudes and arm positions. Here is a comment from the researchers on what they found, it is pretty much what we have been writing about for several years based off of other research"

"The range of motion of the thorax with respect to the pelvis and of the pelvis with respect to the ground in the transversal plane were significantly associated with arm position and swing amplitude during gait. The hip external-internal rotation range of motion statistically varied only for non-dominant limb. Unlike hip joint reaction forces, predicted peak spinal loads at T12-L1 and L5-S1 showed significant differences at approximately the time of contralateral toe off and contralateral heel strike."

Thus, we find yet another study confirming what many will say is obvious, that being arm position and movements have notable effects on whole body kinetics and spinal loads. This study suggested that arm variations did not have an effect on spinal loads during walking. We find this curious; it is something we will be looking into, and pondering. We hope you do as well.

Effect of arm swinging on lumbar spine and hip joint forces. Lorenza Angelini et al. Journal of Biomechanics, Sept 2017
http://www.sciencedirect.com/science/article/pii/S0021929017304670

Cannabis users walk differently.

Screen Shot 2017-09-07 at 9.11.05 AM.png

We all have experienced or viewed the alcohol impaired gait at some point in our lives, the sloppy malcoordinated limb and torso movements. There are some classic observable characteristics there that many of us are familiar with.  But what about cannabis gait ?

"The research from the University of South Australia, published in the journal Drug and Alcohol Dependence, found those who smoke cannabis tend to move their shoulders less and elbows more as they walk. The pilot study also found marijuana users swing their knees more quickly during walking. The differences in gait were small and found in people who smoked a light or moderate amount of cannabis. Some changes were so small it was impossible for a specialist to detect."

However, the thing we found interesting was the papers final question, as to whether the subtle gait changes over a longer period of time would increase or become more apparent.

Not insinuating that Mystic Mac is a user, but he sure does help us hit our "reduced antiphasic gait" home with a glorious demo !

*We have seen this variation in arm swing gait many times before. We have discussed numerous times that when there is a reduction in the normal shoulder and pelvic "girdle" counter rotations, the normal antiphasic gait that presents us with the clearly obvious opposite arm-leg swings, we lose the ability to tap into these oscillations that afford us this free arm and leg swing.  So, when these girdle rotations are reduced, the limb movement has to come from further down into the limb, from elbow movement, a sort of casting the lower arm forward from biceps and triceps activity and from a kicking forward of the lower leg from quadriceps activity instead of hip flexion-extension activity.

We have mentioned this reduction in the normal antiphasic gait many times previously in our arm swing articles. Particularly, the reduction in the amplitude of the separation in the shoulder-pelvic girdle oscillations in those with spine pain. The more the spine is "twisted and wrung out" by these opposite swings, the more spinal motor unit compression, which can increase spine pain. Just search our blog for "arm swing" (30+ articles on the topic there). Thus the question remains , why does cannabis cause this same reduction?

Gait affects everything, and everything seems to affect our gait.

http://www.9news.com.au/national/2017/09/01/15/25/marijuana-users-walk-differently-australian-study-claims

Arm swing asymmetry: It can be a huge window of education into your client.

Arm swing asymmetry: It can be a huge window of education into your client, if you can get past the dumb stuff we’ve all done (and believed) for decades.
I have beaten you down with arm swing principles over the past few years, sorry about that, but, the beating will continue because it is important to know what arm swing tells you, and what it does not tell you (hint hint for all those improperly coaching arm swing changes). We did an entire tele seminar on the Stage 1 principles of of arm swing (#218) on www.onlinece.com and www.chirocredit.com if you wish to take that archived lecture. Heck $19, how can you lose (see photo).  Arm swing is intimately dependent upon scapular stability, thoracic mobility, breathing, cervical spine function, pelvis stability and clearly ipsilateral and contralateral leg swing not to forget to mention spinal stability. The first signs of spine pain or instability and the counter rotation of the shoulder and pelvic girdles become more phasic, instead of their normal anti phasic nature (moving in opposite directions). This phasic nature reduces spinal shear loads.

Neurologic diseases in their early, middle and late phases can give us a clearer window into how the nervous system is tied together.
Arm swing asymmetry during gait may be a sensitive sign for early Parkinson’s disease.

Here is what this Plate et al study found :
-Arm swing amplitude as well as arm swing asymmetry varied considerably in the healthy subjects.
-Elderly subjects swung their arms more than younger participants. -Only the more demanding mental load caused a significant asymmetry
-In the patient group, asymmetry was considerably higher and even more enhanced by mental loads.
-Evaluation of arm swing asymmetry may be used as part of a test battery for early Parkinson’s disease.

Some facts you should consider:
Parkinson’s Disease will be well advanced before the first signs of motor compromise occurs. So early detection and suspicion should be acted upon early when possible. Reductions or changes in arm swing may be the first signs of neuralgic disease expression and progression. Dual tasking may bring out neurologic signs early, so talk to your clients or have them count backwards to distract the motor programs. Look for one sided arm swing impairment, and when present, be sure to examine all limbs, especially the lower limbs, for impaired function. After all, the arms are like balasts, they can help with postural stability simply by abducting or modifying their swing.  Arm swing changes can include:
- crossing over the body
- more forward sagittal swing and less posterior swing
- more posterior sagittal swing and less anterior swing
- shoulder abduction during swing (and with attributes of the prior two mentioned above)
- less swing with adduction stabilized with torso
- modified through accentuations or dampening of shoulder girdle rotation oscillations, thus less arm swing but more torso swing to protect the glenohumeral and other joints
- and others of course

Arm swing and arm swing symmetry matter. Don’t be a dunce and just train it out or tell your client to do things to change it before you identify the “why” behind it. If it were that simple Ivo and I would have long grown tails and begun eating more bananas. Or maybe we would have already moved to the islands by now. That was random wasn’t it. That’s what Jimmy Buffett said.

“Now he lives in the islands, fishes the pilin’s
And drinks his green label each day
He’s writing his memoirs and losing his hearing
But he don’t care what most people say.
Through eighty-six years of perpetual motion
If he likes you he’ll smile then he’ll say
Jimmy, some of it’s magic, some of it’s tragic
But I had a good life all the way.
And he went to Paris looking for answers
To questions that bother him so.”  -Jimmy Buffett

Hope this helps, now back to that rum.
-Shawn Allen

Gait Posture. 2015 Jan;41(1):13-8. doi: 10.1016/j.gaitpost.2014.07.011. Epub 2014 Aug 8.
Normative data for arm swing asymmetry: how (a)symmetrical are we?  Plate A1, Sedunko D2, Pelykh O3, Schlick C4, Ilmberger JR5, Bötzel K6.
http://www.ncbi.nlm.nih.gov/pubmed/25442669

Global body compensations in ACL deficient knees.

ALERT: Ok, this is big.
It is a huge comment on what the brain and reflexive patterns impart on posture and gait when perceived functional instability is present.
This study aimed to investigate the gait modification strategies of trunk over right stance phase in patients with right anterior cruciate ligament deficiency.
* Here is what you need to ABSOLUTLY keep in mind when you read it. The 3D capture it telling you what they are DOING to strategize, not what is WRONG or what needs CORRECTING (our mantra it seems, sorry to keep beating this concept to death). This again hits home what I have been preaching for quite some time, that arm swing (and you can translate that to trunk movements, thorax, head posture, breathing etc) should not be coached or corrected unless you are absolutely sure there are clean symmetrical lower limb biomechanics (yes, you can easily and correctly argue that you can concurrently work on all parts). IF there is something going awry in a lower limb, compensations will occur above, they have to occur. So be absolutely sure you are not making therapeutic interventions above without making therapeutic corrections below. If you are working on a shoulder/upper quarter problem and are not looking for drivers in the lower limbs or in gait, well … . . good luck making lasting effects. Other than breathing, it can be argued well that gait locomotion is our 2nd most engaged motor pattern that we have driven to subconscious levels , and compensations are abound (but not without a cost), so we can dual++ task.
If you want to dive deeper into this, search our blog and look for my articles on Anti-phasic gait. This is essentially what this study was looking at, and confirming, that there is a distortion in the NORMAL opposite phase movements (anti-phasic) of the “shoulder girdle” and “pelvic girdle” when something goes wrong in a lower limb.
- Dr. Allen

Findings from Shi et al when there was a chronic right ACL deficiency:
-trunk rotation with right shoulder trailing over the right stance phase was lower in all five motion patterns
- trunk posterior lean was higher from descending stairs to walking when the knee sagittal plane moment ended
- trunk lateral flexion to the left was higher when ascending stairs at the start of right knee coronal plane moment when descending stairs at the maximal knee coronal plane moment and when descending stairs at the end of the knee coronal plane moment
- trunk rotation with right shoulder forward was higher at the minimal knee transverse plane moment and when the knee transverse plane moment ended
- during walking, trunk rotation with right shoulder trailing was lower at other knee moments during other walking patterns

http://www.ncbi.nlm.nih.gov/pubmed/27131179

Kinetic chain transfer.

Anyone would be silly to disagree with this.
We go into some deeper reasoning back in this older blog post (https://tmblr.co/ZrRYjxTJ6zw9) looking at arm swing and leg swing and pairing of pelvis and shoulder posturing and how clean pelvis function parlays into upper body function in softball pitching.

“Proper utilization of the kinetic chain allows for efficient kinetic energy transfer from the proximal segments to the distal segments. Dysfunction at a proximal segment may lead to altered energy transfer and dysfunction at more distal segments,”

Lower body conditioning may cut upper body injury risk in softball. -Hank Black

http://lermagazine.com/special-section/pediatric-clinical-news/lower-body-conditioning-may-cut-upper-body-injury-risk-in-softball

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

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

Dr. Allen’s Quiz question of the week. See if you can get this one.   Reference point is the Girl in the middle, big sister . Choose all that apply.  Note: there is something deeper than the obvious going on here, it doesn’t make sense. Can you see it ?    a. she (big sister) is out of phase with her little sister   b. she is in phase with her little sister  c. she is out of phase with her little brother  d. she is in phase with her little brother  e.  A and C  f.  B and C  g. B and D  h. A and D  i. AC~DC rules  Yes, Answer  “i” is always right.  otherwise the answer is … . scroll down  .  .  .  .  .  .  .  .   F. she is in phase with her sister to her left and out of phase with her brother (at least if you are referencing her leg swing).  With her little sister, left feet are both forward in swing at the same time.   However, there is something deeper and requires some true critical thinking. IF you got the answer correct, congratulations. IF you did not, type in “in phase gait” or “arm swing” into the blog search engine and you will be able to read more about “in phase” and “out of phase” gaits.    Now, look at the picture again. If she is “in phase” with her little sister to the left big sister should technically have her left arm in anterior/forward swing to meet little sister’s right arm swing. But, big sister’s left foot is forward, which technically means her left arm swing should be posterior to match her normal Anti-phasic gait.  But this does not pair with little sister. Can you see that this is a conflict in synchrony ?     In phase and phasic are not the same thing, nor are out of phase and anti-phasic. Search our blog for these differences.       Obviously you should glean by now that “In and out of phase” gait refers to the leg swing. Whereas, phasic and anti phasic gait refers to the synchrony of the upper and lower limbs in an individual.  The lower limb spinal cord motor neuron pools are more dominant than the upper arm pools (except in climbing, which is why I spent so much time last week talking about climbing and crawling here on the blog). Thus the lower legs often run the protocols and thus why arm swing changes should not be primarily or initially coached or amended in an athlete, they are very adaptive and accommodating.  The legs need to run the show, we need our arms free to be able to carry things while walking or running (water bottle, babies, spears, rifle, brief case etc) without disrupting the normal leg swing gait mechanics.     Big sister is “out of phase” with her brother when it comes to the legs, but their arm swings are matching in phase so that there is no conflict.   When people walk “out of phase” their arm swings will always match. Thus, it would seem that this is the more harmonious way to walk with a partner.     So how are they all walking together ? Certainly not in harmony.  Obviously the little sister is not in sync with big sister. She is much shorter, and thus her step length is going to be different and that is the likely answer. She will have to pick up cadence to keep up and that will mean much of the time she will not synchronize with her big sister. As I mentioned in a prior post on these topics, often the larger or more dominant person’s arm swing will dictate the arm swing pattern of the other partner, and this will in turn, dictate how the lower limbs synchronize to the dominant partner. It would make sense that perfect harmony would bring about “out of phase” leg swing, but it does not always occur. Why? There are many reasons I discussed here today, things like differing arm and leg lengths and step lengths come to mind.  * There is one more option, none of them are in anti-phasic gait. Maybe they all have back pain :) Back pain patients tend to shift towards phasic gait to reduce spinal torsion and shear. If they all are anti-phasic then arm and leg swing matter very little in terms of full limb swing propulsive gait. This is quite possible as well, perhaps this is just a still photo representing a very slow strolling gait and thus little need for anti phasic gaits from all 3 of them.   Neat points if you are a true gait nerd. Did you catch it ? A picture is worth a thousand words.  Hope this little quiz helped you to put some pieces together.   One more thing, here is a clinical pearl.  By walking hand in hand with someone, you can help a person learn arm swing and leg swing and how to create a clean cadence, the normal anti-phasic gait, and learn how to dual task as well as add audible, visual and tactile queues to one’s gait. It is a great tool for helping neurologic gait pathologies, post stroke gait training and helping someone who has joint replacements or back pain regain normal anti-phasic gait traits where gait has become phasic and apropulsive.   Dr. Shawn Allen

Dr. Allen’s Quiz question of the week. See if you can get this one.

Reference point is the Girl in the middle, big sister. Choose all that apply. Note: there is something deeper than the obvious going on here, it doesn’t make sense. Can you see it ? 

a. she (big sister) is out of phase with her little sister 

b. she is in phase with her little sister

c. she is out of phase with her little brother

d. she is in phase with her little brother

e.  A and C

f.  B and C

g. B and D

h. A and D

i. AC~DC rules

Yes, Answer  “i” is always right.

otherwise the answer is … . scroll down

.

.

.

.

.

.

.

.

F. she is in phase with her sister to her left and out of phase with her brother (at least if you are referencing her leg swing).  With her little sister, left feet are both forward in swing at the same time.

However, there is something deeper and requires some true critical thinking. IF you got the answer correct, congratulations. IF you did not, type in “in phase gait” or “arm swing” into the blog search engine and you will be able to read more about “in phase” and “out of phase” gaits.  

Now, look at the picture again. If she is “in phase” with her little sister to the left big sister should technically have her left arm in anterior/forward swing to meet little sister’s right arm swing. But, big sister’s left foot is forward, which technically means her left arm swing should be posterior to match her normal Anti-phasic gait.  But this does not pair with little sister. Can you see that this is a conflict in synchrony ? 

In phase and phasic are not the same thing, nor are out of phase and anti-phasic. Search our blog for these differences.  

Obviously you should glean by now that “In and out of phase” gait refers to the leg swing. Whereas, phasic and anti phasic gait refers to the synchrony of the upper and lower limbs in an individual.  The lower limb spinal cord motor neuron pools are more dominant than the upper arm pools (except in climbing, which is why I spent so much time last week talking about climbing and crawling here on the blog). Thus the lower legs often run the protocols and thus why arm swing changes should not be primarily or initially coached or amended in an athlete, they are very adaptive and accommodating.  The legs need to run the show, we need our arms free to be able to carry things while walking or running (water bottle, babies, spears, rifle, brief case etc) without disrupting the normal leg swing gait mechanics.  

Big sister is “out of phase” with her brother when it comes to the legs, but their arm swings are matching in phase so that there is no conflict. When people walk “out of phase” their arm swings will always match. Thus, it would seem that this is the more harmonious way to walk with a partner. 

So how are they all walking together ? Certainly not in harmony.

Obviously the little sister is not in sync with big sister. She is much shorter, and thus her step length is going to be different and that is the likely answer. She will have to pick up cadence to keep up and that will mean much of the time she will not synchronize with her big sister. As I mentioned in a prior post on these topics, often the larger or more dominant person’s arm swing will dictate the arm swing pattern of the other partner, and this will in turn, dictate how the lower limbs synchronize to the dominant partner. It would make sense that perfect harmony would bring about “out of phase” leg swing, but it does not always occur. Why? There are many reasons I discussed here today, things like differing arm and leg lengths and step lengths come to mind.

* There is one more option, none of them are in anti-phasic gait. Maybe they all have back pain :) Back pain patients tend to shift towards phasic gait to reduce spinal torsion and shear. If they all are anti-phasic then arm and leg swing matter very little in terms of full limb swing propulsive gait. This is quite possible as well, perhaps this is just a still photo representing a very slow strolling gait and thus little need for anti phasic gaits from all 3 of them. 

Neat points if you are a true gait nerd. Did you catch it ? A picture is worth a thousand words.

Hope this little quiz helped you to put some pieces together.

One more thing, here is a clinical pearl. By walking hand in hand with someone, you can help a person learn arm swing and leg swing and how to create a clean cadence, the normal anti-phasic gait, and learn how to dual task as well as add audible, visual and tactile queues to one’s gait. It is a great tool for helping neurologic gait pathologies, post stroke gait training and helping someone who has joint replacements or back pain regain normal anti-phasic gait traits where gait has become phasic and apropulsive. 

Dr. Shawn Allen

Unique adaptations to arm swing challenges: the one armed runner.  Welcome to Luke Ericson, an amazing athlete and man.

Written By Dr. Shawn Allen

Human gait is cyclical. For the most part, when one limb is engaged on the ground (stance phase), the other is in swing phase. Before I continue, you should recall that there is a brief double limb support phase in walking gait, that which is absent in running gait. Also, I wish to remind you of our time hammered principle that when the foot is on the ground the glutes are heavily in charge, and when the foot is in the air, the abdominals are heavily in charge.  

For one to move cleanly and efficiently one would assume that the best way to do that would be to ensure that the lower 2 limbs are capable of doing the exact same things, with the same timing, same skill, same endurance and same strength. This goes for the upper 2 limbs as well, and then of course the synchronizing of the 4 in a cohesive effort. For this clean seamless motor function to occur, one must assume that there would be no injuries that had left a remnant mark on one limb thus encouraging a necessary compensation pattern in that limb (and one that would then have to be negotiated with the opposite limb as well as the contralateral upper or lower limb).  

Removing a considerable mass of tissue anywhere in the body is going to change the symmetry of the body and require compensations. One can clearly see the effects of this on this athletes body in the video above. He even eludes to the fact that he has a scoliosis, no surprise there.  There is such an unequal mass distribution that there is little way the spine had any chance to remain straight.  Not only is this going to change symmetry from a static postural perspective (bulk, weight, fascial plane changes, strength etc) but it will change dynamic postural control, mobility and stability as well as dynamic spinal kinematics.  I have talked about this previously in a blog piece I wrote on post-mastectomy clients display changes in spatiotemporal gait parameter such as step length and gait velocity.

-mastectomy post: http://tmblr.co/ZrRYjx1XB8RhO

If you have been with The Gait Guys for more than a year you will know that impairing an arm swing will show altered biomechanics in the opposite lower limb (and furthermore, if you alter one lower limb, you begin a process of altering the biomechanical function and rhythmicity of the opposite leg as well.) You can search the blog for “arm swing part 1 and part 2″ for those dialogues.

Arm swing impairment is a real issue and it is one that is typically far overlooked and misrepresented. The intrinsic effects of altering the body through subtraction of tissue are not all that dissimilar to extrinsic changes into the system from things like  walking with a handbag/briefcase, walking with a shoulder bag, walking and running with an ipod or water bottle in one hand. And do not forget other intrinsic problems that affect spinal symmetry, for example consider the changes on the system from scoliosis as in this case.  It can cycle back on its own feedback loop into the system, either consciously or unconsciously altering arm swing and thus global body kinematics.  

There is a reason that in my practice I often assess and treat contralateral upper and lower limbs as well as to address remnants from old injuries whether they are symptomatic or not. It all comes together for the organism as a concerted effort in optimal locomotion.

Here on TGG, and in dialogues with Ivo on our podcast, I have long talked about phasic and anti-phasic motions of the arms and shoulder-pelvic blocks during gait and locomotion/sport activity.  I have written several times about the effects of spine pain and how spine pain clients reduce the anti-phasic rotational (axial) nature of the shoulder girdle and pelvic girdle. In the video above, you can see anything but anti-phasic gait, to be clear, this is a classic representation of a phasic gait. The shoulder block and the pelvic block show little if any counter rotation, they are linked together which is not normal gait. Furthermore, if you look carefully, the timing of the right arm swing is variable and cyclically changing in its timing with the left leg. Look carefully, you will see the cyclical success and failure at the beginning of the video.  This is pathologic gait, he must be constantly fighting frontal plane sway because there is no axial anti-phasic motion. He is also constantly fighting the unidirectional rotation that the absence of an entire limb and limb girdle is presenting, you can see him struggle with this if you have looked at enough gait samplings. There is essentially frozen torso movements.  Want to see more of our work on arm swing ? search the gait guys blog.

There is so much more here to discuss, so I will likely return to this video another time to delve into those other things on my mind. Luke is an amazing athlete, he gets much respect from me.

I hope this dialogue helps you to get a deeper grip on gait and gait problems. I have written many articles on the topics of arm swing, phasic and anti-phasic gait, central pattern generators. The are all archived here on the blog. I try to write a new original thought-process article each week for the blog amongst the other “aggregator” type stuff we share from other folks social media. My weekly article serves to go deeper into things, sometimes they are well referenced and in this case, I am basing today’s discussion on the referenced work in the other pieces I have written on arm swing, phasic and anti-phasic gait, central pattern generators etc. So please do your readings there before we begin debate or dialogue, which i always welcome !

Dr. Shawn Allen

Spinal interneuronal networks linking the forelimbs and hindlimbs

Do the intimate relationships of the upper limbs and lower limbs suggest that quadrupedal skill sets, if not true quadrupedal gait, were a piece of our past locomotion strategies ?  Or is it just representative of the close linkages for gait efficiency? Or maybe both?

In this study below the researchers pondered whether lower limb motor function can be improved after a spinal cord lesion by re-engaging functional activity of the upper limbs. Although this study looked at spinal cord hemisections in adult rats we know there is likely human correlation. This study showed improved hindlimb function when the forelimbs were engaged simultaneously with the hindlimbs during treadmill step-training as opposed to training only the hindlimbs.
As we have proposed here on the gait guys blog many times previously, this study’s results provide strong evidence that actively engaging the forelimbs improves hindlimb function and that one likely mechanism underlying these effects is the reorganization and re-engagement of rostrocaudal spinal interneuronal networks.
“For the first time, we provide evidence that the spinal interneuronal networks linking the forelimbs and hindlimbs are amenable to a rehabilitation training paradigm. Identification of this phenomenon provides a strong rationale for proceeding toward preclinical studies for determining whether training paradigms involving upper arm training in concert with lower extremity training can enhance locomotor recovery after neurological damage.”

This likely has huge implications in rehab measures and gait retraining for those who are not spinal cord impaired as well.  We have discussed many times that making a single limb change merely because the observer/clinician does not like the functional appearance of a limb is a  mistake most of the time. That what we see is a compensation, not the problem.  Go back and review our many “arm swing” blog posts, you should recall that the arms can have a huge impact on the leg function and that many times the arms take their cues from the lower limbs during gait.  This is a topic we have hammered many times in many blog posts and in many courses we have taught.  It is nice to see the literature continue to support the close relationships of the 4 limbs on a neurologic level.


Brain. 2013 Nov;136(Pt 11):3362-77. doi: 10.1093/brain/awt265. Epub 2013 Oct 7.

Use of quadrupedal step training to re-engage spinal interneuronal networks and improve locomotor function after spinal cord injury.

Shah PK1, Garcia-Alias G, Choe J, Gad P, Gerasimenko Y, Tillakaratne N, Zhong H, Roy RR, Edgerton VR.

Human gait is cyclical. For the most part, when one limb is engaged on the ground (stance phase), the other is in swing phase. Before we continue, you should recall that there is a brief double limb support phase in walking gait, that which is absent in running gait. Also, we wish to remind you of our time hammered principle that when the foot is on the ground the glutes are heavily in charge, and when the foot is in the air, the abdominals are heavily in charge.   
 For us to move cleanly and efficiently one would assume that the best way to do that would be to ensure that the lower 2 limbs are capable of doing the exact same things, with the same timing, same skill, same endurance and same strength. This goes for the upper 2 limbs as well, and then of course the synchronizing of the 4 in a cohesive effort. For this clean seamless motor function to occur, one must assume that there would be no injuries that had left a remnant mark on one limb thus encouraging a necessary compensation pattern in that limb (and one that would then have to be negotiated with the opposite limb as well as the contralateral upper or lower limb).  For example, when right ankle rocker (dorsiflexion) is impaired, early heel departure will occur and hip extension will be limited. An alteration in right glute function will most likely follow.  One could theorize that the left step length (the length of measure from right heel strike through to left heel strike) would thus be shortened. This would cause a premature load onto the left limb, and could very well force the left frontal plane to be more engaged than is desirable. This could lead to left core and hip frontal plane weakness and compensation patterns to be generated (ie. right arm abduction. One can see all of these components in the photo above, and in  this case here ). It could also lead to a pelvic distortion pattern which would further throw off the anti-phasic nature of symmetrical and efficient gait.  To complicate the cyclical scenario, the time usually used to move sagittally will be partially used to move into, and back out of, the left frontal plane. This will necessitate some abbreviations in the left stance phase timely mechanical events. Some biomechanical events will have to be abbreviated or sped through and then the right limb will have to adapt to those changes. These are simple gait problems we have talked about over and over again here on the gait guys blog. (Search “arm swing” on our blog and you will find 45 articles around this topic.) These compensation patterns will include expressed weaknesses in various parts of the human frame as part of the pattern, and merely fixing those weaknesses does not address the right ankle rocker problem. Fixing said weaknesses merely encourages the brain to possibly continue to perpetuate necessary tightnesses in other muscles and engrain the compensations (challenges to mobility and stability) further or more complexly.  It is easy to find something weak, it takes a sharp brain to find the sometimes silent sparking event. Are you able to find the problem in this never ending loop of compensations and find a way to unwrinkle the system one logical piece at a time, or will you just chose to strengthen the wrinkled system and hope that the new strength on top of the compensations is adequate for you our your client ? One should not be forever sentenced to daily or weekly rehabilitative sessions/ homework to negate and alleviate symptoms, this is a far more durable machine than that. Fix the problem. 
 Now, lets add another wrinkle to the system.  What if there were problems before any injuries ?  Meaning, what if there were problems during the timely maturation and suppression of the primitive reflexes ? Or problems in the timely appearance or maturation of postural reflexes? A problem in these areas may very well result in a central or peripheral nervous system malfunction and a representation of such in one’s movement and gait.  That is a larger discussion for another time. 
  There is a reason that in our practices we often assess and treat contralateral upper and lower limbs as well as to address remnants from old injuries whether they are symptomatic or not. This is a really tough puzzle and game you are playing. For example, when there is insufficient hip internal rotation unilaterally you can regain some of the loss through increased foot pronation unilaterally, but at a consequence to both the local and global pictures.  Remember, most of the time you are trying to walk in a straight line from A to B and if the parts are not symmetrical you have many options to compensate.   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”. It is often not as simple as finding an impaired Rolling Pattern and driving it back to symmetry, in doing so, you may have just added strength and skill to a compensation.  Merely addressing things locally can be 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, lateral flexion and hinging as well as core mobility and stability.  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.  So, those need assessed and addressed as well.    
  Or, if this is too much thinking for you, … you can just train harder and get stronger . .  . in all your compensation patterns, after all, it is easier than figuring out why and how that right ankle started the whole mess, if in fact that is even the first piece of the puzzle.  
  Welcome to the matrix.  
  shawn and ivo, the gait guys

Human gait is cyclical. For the most part, when one limb is engaged on the ground (stance phase), the other is in swing phase. Before we continue, you should recall that there is a brief double limb support phase in walking gait, that which is absent in running gait. Also, we wish to remind you of our time hammered principle that when the foot is on the ground the glutes are heavily in charge, and when the foot is in the air, the abdominals are heavily in charge.  

For us to move cleanly and efficiently one would assume that the best way to do that would be to ensure that the lower 2 limbs are capable of doing the exact same things, with the same timing, same skill, same endurance and same strength. This goes for the upper 2 limbs as well, and then of course the synchronizing of the 4 in a cohesive effort. For this clean seamless motor function to occur, one must assume that there would be no injuries that had left a remnant mark on one limb thus encouraging a necessary compensation pattern in that limb (and one that would then have to be negotiated with the opposite limb as well as the contralateral upper or lower limb).  For example, when right ankle rocker (dorsiflexion) is impaired, early heel departure will occur and hip extension will be limited. An alteration in right glute function will most likely follow.  One could theorize that the left step length (the length of measure from right heel strike through to left heel strike) would thus be shortened. This would cause a premature load onto the left limb, and could very well force the left frontal plane to be more engaged than is desirable. This could lead to left core and hip frontal plane weakness and compensation patterns to be generated (ie. right arm abduction. One can see all of these components in the photo above, and in this case here). It could also lead to a pelvic distortion pattern which would further throw off the anti-phasic nature of symmetrical and efficient gait.  To complicate the cyclical scenario, the time usually used to move sagittally will be partially used to move into, and back out of, the left frontal plane. This will necessitate some abbreviations in the left stance phase timely mechanical events. Some biomechanical events will have to be abbreviated or sped through and then the right limb will have to adapt to those changes. These are simple gait problems we have talked about over and over again here on the gait guys blog. (Search “arm swing” on our blog and you will find 45 articles around this topic.) These compensation patterns will include expressed weaknesses in various parts of the human frame as part of the pattern, and merely fixing those weaknesses does not address the right ankle rocker problem. Fixing said weaknesses merely encourages the brain to possibly continue to perpetuate necessary tightnesses in other muscles and engrain the compensations (challenges to mobility and stability) further or more complexly.  It is easy to find something weak, it takes a sharp brain to find the sometimes silent sparking event. Are you able to find the problem in this never ending loop of compensations and find a way to unwrinkle the system one logical piece at a time, or will you just chose to strengthen the wrinkled system and hope that the new strength on top of the compensations is adequate for you our your client ? One should not be forever sentenced to daily or weekly rehabilitative sessions/ homework to negate and alleviate symptoms, this is a far more durable machine than that. Fix the problem.

Now, lets add another wrinkle to the system.  What if there were problems before any injuries ?  Meaning, what if there were problems during the timely maturation and suppression of the primitive reflexes ? Or problems in the timely appearance or maturation of postural reflexes? A problem in these areas may very well result in a central or peripheral nervous system malfunction and a representation of such in one’s movement and gait.  That is a larger discussion for another time.

There is a reason that in our practices we often assess and treat contralateral upper and lower limbs as well as to address remnants from old injuries whether they are symptomatic or not. This is a really tough puzzle and game you are playing. For example, when there is insufficient hip internal rotation unilaterally you can regain some of the loss through increased foot pronation unilaterally, but at a consequence to both the local and global pictures.  Remember, most of the time you are trying to walk in a straight line from A to B and if the parts are not symmetrical you have many options to compensate. 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”. It is often not as simple as finding an impaired Rolling Pattern and driving it back to symmetry, in doing so, you may have just added strength and skill to a compensation.  Merely addressing things locally can be 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, lateral flexion and hinging as well as core mobility and stability.  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.  So, those need assessed and addressed as well.  

Or, if this is too much thinking for you, … you can just train harder and get stronger . .  . in all your compensation patterns, after all, it is easier than figuring out why and how that right ankle started the whole mess, if in fact that is even the first piece of the puzzle.

Welcome to the matrix.

shawn and ivo, the gait guys

This Client went Phasic in their Gait. Do you know what that means ? We do, and so does McGill, Liebenson, Cook and many others.

Long ago on this blog we showed and discussed a video (link) that discussed Stu McGill's research of the human movements of Georges St-Pierre and David Loiseau. The basic tenets of that video were that the hips and shoulders are used for power production and that the spine-core are used for creating stiffness and stability for the ultimate power transmission through the limb.  He made it clear that if power is generated from the spine, it will suffer. 

Here on TGG we have long talked about phasic and antiphasic motions of the arms and shoulder-pelvic blocks during gait and locomotion/sport activity.  Many of our 1000+ blog writings and 80 podcasts have talked about spine pain and how spine pain clients reduce the antiphasic rotational (axial) nature of the shoulder girdle and pelvic girdle. In the video above, we see anything but antiphasic gait, to be clear, this is a classic representation of a phasic gait. This is pathologic gait, the frontal plane sway is exaggerated and necessary because there is no axial antiphasic motion.  There is essentially frozen arm and torso movements. This client has a long standing history of severe spine trauma and pain, their central pattern generators (CPG) had to make this motor pattern choice in an attempt to avoid pain and negotiate force streams across trauma zones. If you are curious and wish to go deeper down this rabbit hole, read the 30+ articles we have produced more specifically on arm swing and locomotor phasics, just click here.

In these types of cases, the client subconsciously makes the subcortial pattern choice (overrides the normal CPG) to rotate them as a solid unit to reduce spine rotation, axial loading and compression.  We could say that quite often spine pain disables the normal arm-leg pendulums via altering the shoulder-torso and hip-pelvis phasics and the CPG that dictates them. Normally, the spine and core must present sufficient amounts of recruited stiffness, yet mobility where necessary, to enable the locomotive power and velocity generated by movements of the shoulders and hips. These are the two main portals of limb movement off of the spine/core.  These principles holds true in gait and sport. For and interesting example, in human gait the psoas is not entirely a hip flexor initiator when it comes to leg swing, it is a huge hip flexion perpetuator. The initial hip flexion in human gait comes from derotating the obliqued pelvis, via abdominal contraction, on a stiff and stable spine.  Once the pelvis rotation is initiated, the femur can further pendulum forward (via contraction of the psoas and other muscles) on the forward accelerated pelvis in the hip joint proper creating an energy efficient movement (the towel flick/whip effect). This premise holds true in gait, running, kicking etc.  This is a solid principle of effective and efficient human locomotion. This principle also holds true for a punch or throwing an object, the stable torso/spine provides a stable anchor upon which to accelerate the arm in order to create a high velocity limb movement with power.  But here is where we get annoyed much of the time.  (Soap box Tangent coming up) How often do you read articles about tight ITBand, tight psoas, tight piriformis and the like ?  As a “diagnosis” these are weak and they are the “go to diagnosis or cause” of the unseasoned clinician, trainer, coach, therapist. If we all are to be really good at our job, we must go beyond what we see in someone’s gait (since it is the compensation) and go beyond the CNS neuroprotective strategy of tightness/shortness when there is weakness or motor pattern failure.  This does not mean that you cannot, or should not, incorporate restoration methods and principles to restore length-tension relationships in your client, it means you have to resolve ALL of the problems, including the aberrant CPG they have set up as a protective default to avoid injury or further injury. 

In the case above, returning the discussion to arm and leg swing, one must understand clearly that faulty arm swing patterns and lack of antiphasic torso and pelvis oscillation is a product of surgery,  trauma and more so, pain. The client is avoiding the antiphasic presentation (hence, he is phasic) for a reason and coaching more arm swing would be just about the dumbest intervention, so don’t be “that guy”. We know this is an altered motor pattern choice, not a new fixed set point. We know this because on clinical examination the range is available, we know because we examined for it, it is just not being used.  In an example of this same principle, in this case talking hip ranges of motion, McGill discusses the same in his paper*:

“Despite the large increases in passive hip ROM, there was no evidence of increased hip ROM used during functional movement testing. Similarly, the only significant change in lumbar motion was a reduction in lumbar rotation during the active hip extension maneuver (p < 0.05). These results indicate that changes in passive ROM or core endurance do not automatically transfer to changes in functional movement patterns. This implies that training and rehabilitation programs may benefit from an additional focus on grooving new motor patterns if newfound movement range is to be used.”

Think about that next time you stretch, or are stretched by someone. As we have said before, just because you increase someone’s range of motion, does not mean they will be able to incorporate that range of motion into a movement pattern, or compensation pattern for that matter. It is only ¼ of the equation: Range of Motion,  Skill (or proprioception),  Endurance (or the proportion of slow twitch muscle) and Strength (the proportion of fast twitch muscle). There is our S.E.S. mnemonic again.

In this video case, lack of NORMAL antiphasic spinal motion (torso and pelvis moving opposite one another) is noted. Without the obliqued pelvis the swing and stance phases will be impaired. The psoas may have to become more of a hip flexor initiator, AS WELL AS the perpetuator of limb swing, because there is no pelvic obliquity from the antiphasic principles to drive it from. And so, when you see this fella in your office with bilateral tight psoas/hip flexor complex and tight quadriceps mechanisms with resultant impaired glutes and hip extension, please do not begin lengthening them as your point of initiation.  They are that way because he has gone phasic in his gait.  Change the motor patterns that drive this as best as possible, restore any weaknesses that are contributory to, or initiate, these motor patterns and then, if needed, encourage some progressive new length-tension in these muscle groups as improved motor patterning evolve to allow for it.  You are likely going to have to go back and reteach and restore primitive and postural sensory motor windows in these cases, so be patient, be kind, be wise. Oh, and do not forget that with impaired hip function, there will most likely be impaired ankle rocker,  you are going to need a wide angled lens to see, capture and remedy this lads problems.

On another note, can you imagine what this client’s video gait analysis would show and interpret ? Let alone the diagnostics and recommendations that could come from it?  What about the appearance of their foot pressures across a dynamic foot pressure plate (or God forbid a static one !), surely what is seen at the foot is this client’s problem (not !) And forgive those poor fools who recommend a shoe for this client based off of just those mediums alone.  Without a complete hands-on clinical examination to correlate gait cycle observances, any recommendations for this case will be traumatic on many levels. 

Today’s bottom line……. read, learn, think, stay hungry, be wise.

Shawn and Ivo, The Gait Guys

* Improvements in hip flexibility do not transfer to mobility in functional movement patterns.  Moreside, Janice: McGill, Stuart

link: http://journals.lww.com/nsca-jscr/Fulltext/2013/10000/Improvements_in_Hip_Flexibility_Do_Not_Transfer_to.1.aspx

tumblr_n4uooo1jnw1qhko2so1_1280.png
tumblr_n4uooo1jnw1qhko2so2_r1_1280.png

Spine pain and arm swing. Do you truly get this ? You had better.

We have all seen that runner who swings the one  arm more than the other, they may even violently thrust the one arm across the front of the torso. If you have been a spectator half way through any race you have seen this person. And, if you are watching carefully in your gym, lab, office or gait lab  you have seen the accentuated arm swing on one side (or is it the loss of arm swing on the opposite, we discussed some of these games in last weeks blog post here). You have also see the person who is running with a water bottle in their hand and altering their neurological arm-leg swing opposite pairing and thus their anti-phasic shoulder-pelvic girdle pairing (see attached photo). (If you are lost when we discuss the terms phasic and anti-phasic you will want to go and read this previous blog post.

Knowing that which you are seeing in your client is their highest level of neurologic motor compensation, and not likely their problem, represents a higher thought process in a diagnostician. Unfortunately, it also opens a whole bunch of clinical thought process mental gymnastics. 

Our purpose of today’s blog post is to revisit an important aspect of the clinical examination, observation.  Listening and watching (and knowing what you are seeing, and not seeing) are two of the biggest pieces of a clinical exam other than the hands on assessments. One has to be good at all of the pieces.  But then their is the knowledge base that is needed to base the information and choices upon so that the proper path to remedy can be chosen.  Without the knowledge the actions and choices can be dramatically incorrect and devastating to an athlete or client/patient.  Make the wrong choice for a patient and they do not get better, perhaps even get worse. Make the wrong choice for an athlete and you deepen their compensation and increase their risk for injury.  This is one of our pet peeves because we recognize that we have a deep knowledge base and yet we find ourselves without the certainty and answers on a regular basis and yet we see people making similar choices for clients and athlete with only a small piece of the knowledge necessary on their table to make those choices.  If you don’t know what you don’t know, and yet your still swimming in the risky waters, you are already in deep trouble. 

Here are two articles that you should be familiar with. We talk about them in depth in our “arm swing” online course #317 here.  These articles talk about phasic and antiphasic motions of the arms and shoulder-pelvic blocks.  They talk about spine pain and how spine pain clients reduce the antiphasic rotational (axial) nature of the shouder girdle and pelvic girdle. They elude to the subcortial pattern of choice to rotate them as a solid unit to reduce spine rotation, axial loading and compression and that spine pain disables the normal arm-leg pendulums.  If you do not know and  understand these principles, and you are training, treating or coaching people, you are a problem waiting to happen for your client. You, are the problem and your choices could likely hurt your client.  IF you do not know how to address them or fix them safely, it is your job to send them to someone who does. 

So the next time you see an aberrant arm swing, during your exam, your observations and your history better delve into all things relevant. How about that 20 year “healed” ankle fracture that your client dismisses as “oh, but that was 20 years ago, its not part of this problem i am having now”.  How about that episode of frozen shoulder that was “fixed” 15 years ago or that episode of hip or knee pain from falling on ice or the random big toe pain or the headaches ?  If they dismiss all of this because they are just coming to see you for spine pain or because their running partner says their arm swing stinks on the right you had better sit down for a longer ride, because you  know better now.  Unless you prefer to see life through tunnel vision. Sure it is easier, but don’t you want more for your client ?

Sorry for the rant.

Shawn and Ivo, …… the gait guys.

1. Eur Spine J. 2011 Mar;20(3):491-9. doi: 10.1007/s00586-010-1639-8. Epub 2010 Dec 24.
Gait adaptations in low back pain patients with lumbar disc herniation: trunk coordination and arm swing.  Huang YP et al.
2. J Biomech. 2012 Jan 10;45(2):342-7. doi: 10.1016/j.jbiomech.2011.10.024. Epub 2011 Nov 10.

Mechanical coupling between transverse plane pelvis and thorax rotations during gait is higher in people with low back pain.

The weeping calf and the deconstructed arm swing.

Last week we showed you this video and blog post of a compressive left lower leg neuropathy and what it looks like when both heel and toe walking are attempted when both are compromised. It was nothing exciting but to see both in a clinical presentation is not all that common.

In today’s videos (the one above and this one here), the videos were all shot on the same day incidentally, we wanted you to see this gentleman’s gait in it’s normal gait pattern attempt.  Because less of the extremes of range and strength are required, it is far more difficult to detect the issues than in last week’s video clip (here).

There are plenty of things to talk about in this video but lets just point out one of them here today.  Remember, the lesion is in the left lower leg.

Absent right arm swing. 

We have been harping about arm swing for a long time.  Go to the search box here on our blog and type in “arm swing” and you will find an abundance of articles on the biomechanics and neurology of arm swing and how it is tied to leg swing.  In this case we have foot drop and impaired calf raise (video link) on the left. Their function is impaired/depressed. We are seeing this matching in the absence of right upper limb swing.  Remember, most of the time the upper limb takes the queue from the opposite lower limb. This is why coaching arm swing changes is not a sound idea most of the time, look for functional opportunities for changes in the opposite lower limb if deficits are present there.  

Part of what you are seeing is the increased activity in the left arm swing.  Why ? Because the client is abruptly lurching off of the left leg because of the stability and strength deficits in that limb. The brain knows that bearing weight on the left limb has challenges.  This causes an abrupt pitch (early departure) forward onto the right leg and this will be met with increased left arm swing (go limb around your home or office, you will see that it is a coupled phenomenon).  So, is it increased left arm swing you are seeing because of this issue we just mentioned or are you seeing decreased right arm swing because of the matching neuro-suppression of left leg ? 

This is where your clinical examination must come into play. Shame on anyone that is making the changes without clinical information. One must see that there rare two (at least) possible scenarios for the differential in arm swing. And one must also see that the arms in this case are not the issue, that it is the left lower limb deficits that are driving the issue.  Guaranteed.

Arm swing……..more to it than you might think.

Shawn and Ivo, The gait guys