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

Ankle inversion sprain ? or off-loading photo ?

How we do one thing, is how we do all things.

I was sitting having my morning coffee earlier than normal this morning, which left me time to ponder some things.
Look at this picture, is this not a magnification of the "cross over gait" x100 ? Thus, is that planted foot not inverted ? Yes, it has to be, to a degree, a high degree. There is a reason why soccer players have a great affinity for ankle sprains.
When we have a narrow based gait, we are most likely going to strike more laterally on the foot, more supinated, if you will. If you widen step width, less inversion, less lateral forces (typically) and less supination (typically) compared to a narrow based gait.
If we descend stairs with our feet in a more narrow based gait, we are not only going to be inverted more, but striking at the ball of the foot, thus, more on the lateral foot tripod. This is the typical inversion sprain injury position.
When we jump, we should be trying to land with our feet more abducted, certainly not narrow based, because if we are too narrow we are at more risk for the same lateral forefoot landing and thus ankle inversion event. Just like descending stairs.

We see plenty of ankle inversion events. Why?
Because most people do not have enough hip abduction or peroneal skill, strength, endurance and they are unaware of their weak gait patterns or their ankle spatial awareness. Many have lazy narrow based gaits and insufficient proprioceptive awareness. And, they carry these things over into running, walking, jump landing (ie. volleyball, basketball, etc), and descending stairs, just to name a few.

How we do one thing, is how we do all things (mostly).

Rickie Lovell As he struck the ball it would been everted. The momentum of the follow through will have off loaded the everted foot as the energy moves in a similar line to that of the ball. It is extremely rare for a footballer to get a sprain from this, I certainly didn't see over several years working in professional football.
On a side note, find some footage of David Beckham taking free kicks - the mechanics are astounding!

The Gait Guys possibly everted, but no guarantee.It still looks pretty inverted to me.But we see your point, and is a real good one, real good. Super good. We will check our the bender-man thanks for chiming in with such great insight !

The Gait Guys yes, the momentum of the leg kicking across the body would externally spin the stance leg. The picture is likely showing the offloading phase, not the loadin

Rickie Lovell The benefits of being a Brit that used to play!

The Beef on the EDL.....

We have long been promoting appropriate function of the long extensors of the toes  here, in our practices, our lectures, on Youtube, in our book......You get the idea. Lets take a closer look at this often weakened and overlooked muscle.

We remember that the EDL lies mostly in the superior and somewhat lateral part of the anterior compartment of the lower leg, comprising approximately the upper 2/3 from under the lateral tibial plateau and fibula, and from the interosseus membrane. It lies under the tibialis anterior, and the extensor hallucis longus lies below it. Its tendons pass inferiorly and travel under the extensor retinaculum and attaches to the base of the distal phalanges of toes 2-4. These muscles act from initial contact to loading response to help eccentrically lower the foot to the ground and ensure smooth heel rocker and most likely attenuate the speed of initial pronation as the talus glides anteriorly on the calcaneal facets and again from terminal stance through initial swing to provide compression of the metatarsal phalangeal and interphalangeal joints, to offset the long flexors (which are often overactive) and create clearance for the toes during swing.  

What does it look like when the long extensors don’t work so well? Have a look at the pedograph on the right (pair J howard r). what do we see? First we notice the lack of printing under the head of the 1st metatarsal and increased printing of the second metatrsal head. Looks like this individual has a forefoot supinatus, or possibly a forefoot varus (cannot get the head of the 1st metatarsal to the ground, and thus a weak medial tripod, possibly insufficient extensor hallucis brevis, peroneus longus, flexor digitorum brevis, or all of the above). Next we see increased printing of the distal phalanges of digits 2-4. Looks like the long flexors are dominant, which means the long extensors are inhibited. What about the lack of printing of the 5th toe? I thought the flexors were overactive? They are, but due to the supinatus, the foot is tipped to the inside and the 5th barely contacts the ground!

How do you fix this?

• Help make a better foot tripod using the toe wave, tripod standing and extensor hallucis brevis exercises.
• Make sure the articulations are mobile with joint mobilization, manipulation and massage.
• How about dry needling and acupuncture to improve function?
• Make sure the knee and hip are functioning appropriately.
• Put them in footwear that will allow the foot to function better (a less rigid, less ramp delta shoe).
• As a last resort, if they cannot make an adequate tripod because of lack of motivation, anatomical constraints or both, use a foot leveling orthotic.

Threshold foot drop. Video case.

Threshold foot drop.
Do you see it in this gait? No. There is a clue though, the EHL on the right (extensor hallucis longus) does not seem to be all that hearty and robust during gait, the toe is not as extended/dorsiflexes as on the left foot. A Clue ? Yes.
This client had true blatant foot drop, but it was caught relatively immediately, and the source resolved and recovery ensued. There is still some residual weakness, as you see at the end of the video, but making steady gains. Previously, gait showed obvious foot drop, foot slap, abrupt knee flexion (the "catch" response as we call it as the client's knee suddenly flexed forward as foot slap occurs). But, as you can see , the gait is pretty much normal now except for a little EHL strength lag. But, at the end of the video, when they heel walk, one can see the weakness, they cannot keep the ball of the foot off the ground during attempted heel walk. We like to call this "threshold weakness", it is just hovering below the surface, when taxed, it can be seen, but doesn't show up in gait. But, it does show up in longer endurance based walking events. This may be when your client's symptoms show up, as fatigue expresses limitations in the system. It just goes to show you, if you are not testing and looking for these things, you just might not find the source of your clients knee pain, foot pain, hip or low back pain. Heel and toe walking takes 10 seconds, do not forget to check them off. It just might be the "big reveal" for you, and them ! #footdrop #gait

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Building a Better Bridge

Using bridge exercises? Want to make it more effective? Here's one simple way: bend the weight bearing knee to 135 degrees rather than the traditional 90. It preferentially activates the g max and med more (relatively, compared to the hamstring ; the actual values for the max and med remained similar) and the hamstring significantly less (24% vs 75%)

CONCLUSION:

"Modifying the traditional single-leg bridge by flexing the active knee to 135 ° instead of 90 ° minimizes hamstring activity while maintaining high levels of gluteal activation, effectively building a bridge better suited for preferential gluteal activation.

Lehecka BJ, Edwards M, Haverkamp R, et al. BUILDING A BETTER GLUTEAL BRIDGE: ELECTROMYOGRAPHIC ANALYSIS OF HIP MUSCLE ACTIVITY DURING MODIFIED SINGLE-LEG BRIDGES. International Journal of Sports Physical Therapy. 2017;12(4):543-549.

link to free full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5534144/

Arm swing during gait. An energetic cost of locomotion?

"Arm swing during gait has an important role in decreasing energetic cost of locomotion. Several pathologies
may lead to various abnormalities in arm movements during
walking. It may therefore be expected that pathological gait is
energetically more demanding, not only because of the pathology, but also because of affected arm movements."- Meyns et all.

The Gait Guys ponder:
Can forcing what we think is a "better" arm swing pattern in turn be considered generating locomotor pathology? After all, we very well may be forcing a change to that which we see, a visual which we do not like, which was already a fundamental compensation around another locomotor deficit. ???

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

You won't read this. So send it to a colleague who will.

Beating a point to near-death. Consider this our Thursday Rant.

Yes, we won't let this go, and, you should not either.

We highlight the word ADAPTIVE below, because it is the key to all of this.

"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 N1, Sporbert C, Pinsault N.

When one prescribes or chooses a corrective exercise for a client, one based sheerly on what is visualized as an "apparently" faulty movement pattern or aberrant screen, one is making many assumptions. Assumptions that are likely not entirely correct (we are being kind, most assumptions made based on partial fragmented information are incorrect to a high degree).

Here is comes again, . . . . what you SEE and TEST in your client's movement is not what is wrong with them most of the time. What you see is how your client is ADAPTING to the variables they can engage, avoiding the ones that are painful or perceived as unstable, or finding ways around immobility and as the article as quote above suggests. This was a basic tenet of Karel Lewit's and Janda's work to not focusing on the area of pain, rather to seek out the root cause, we are just saying it in a different manner.

Continuing, we also adapt around fatigue which can take place even in everyday tasks and how we move around our world, yes, even in our gait. Yes, you are seeing a client's best attempts, ones that are likely deeply rooted and now their new norm, their baseline to base all other patterns off of. Their attempts can be based off of immobility, instability (true or functional), lack of skill, proprioceptive deficits, fatigue (lack of baseline endurance), lack of strength or power. For some clients, forget challenging screens that really test them, heck, we find some athletes do not even have the requisite baseline endurance or strength in a few primary fundamental patterns of which they have built more robust patterns atop of. We all to often read about "robustness" of a skill and pattern and interpret it as a good thing. Robustness can also be build atop of a bad pattern of movement, atop of poor stability patterns.

Thus, asking a client to change that ADAPTIVE norm, based off of what you visualize, based on the working parts available to them, without rooting out the cause, is asking them to compensate around their new norm base of compensation. When done this way, we are merely giving our client armor to their dysfunction, faulty robustness if you will. We are in fact moving further from the remedy. To correctly play this multi-layered game of helping people, one has to examine the client, not just put them through screens and assessments that show us (and them) what they can and cannot do.

There is an awful lot of armchair doctoring going on out there, thankfully it all comes from a good place in the heart's of many good folk. We have so many people come in to see us who have problems and a list of corrective exercises that have been prescribed to them, exercises that clearly have been based off of correcting what is seen in their screens and movements. We discuss their workout patterns, their activities, and hear about how they are attempting to build up their bodies for the apparent good. But all to often, with a client in front of us in pain, we hear the clues that the problem is being exercised around. Meaning, building robustness on top of a dysfunctional base somewhere in their system. Many of these people have been given these exercises as part of their corrective work and strengthening programs at their place (gym, box, trainer, coach etc). Many times there was no in depth hands on examination coupled with screens and gait to root out the cause of why they are moving the aberrant way that they are. We all must commit ourselves to a complete process for our clients. Screens and tests and exercises are not enough. Please read yesterdays post if you have not already, we make our point once again in a video case.

To close this post, we fully acknowledge regularly that we are on the same bus to the same temple of higher wisdom as everyone else that reads these kinds of posts. We write to share, but we write to learn, to dive deeper into our thoughts, to challenge our biases and rooted assumptions through thought experiments, challenging thoughts and old ways that get us into troubled automated patterns of approaching all things. Again, we write to learn. And, part of that learning is accepting our limitations and hearing from others who are wiser in other areas than us, so, please comment and add insight below if you wish. Debates are good, for us all.  Pull up a chair, grab a pint, join us around the hearth for some gab.

Shawn Allen, . . .  the other gait guy.    www.doctorallen.co    &    www.shawnallen.net

"One of the few ways I can almost be certain I'll understand something is by sitting down and writing about it. Because by forcing yourself to write about it and putting it down in words, you can't avoid having to come to grips with it. You might be wrong, but you have to think about it very intensely to write about it. So I use writing as a learning tool. " - Hunter S. Thompson

*Postural adaptation to unilateral hip muscle fatigue during human bipedal standing.

Gait Posture. 2009 Jul;30(1):122-5. doi: 10.1016/j.gaitpost.2009.03.004. Epub 2009 Apr 28.

Vuillerme N1, Sporbert C, Pinsault N.

Is this a gluteus medius foot targeting problem in swing phase or is this a loss of internal hip rotation? Or . . . .

Is this a gluteus medius foot targeting problem in swing phase or is this a loss of internal hip rotation? Or . . . .

You have to examine your client to know what to treat, a gait analysis or a series of screens is not enough. The saying "an exercise is a test and a test is an exercise" has some sharp edges around it. A screen doesn't tell you what exercise a client necessarily needs or should be prescribed.
This stuff really does matter.
What you see is not the problem , it is their compensatory strategy in coping with a problem. When someone has a pebble in their shoe and they walk on the outside edge of their shoe to avoid the pebble the solution is not to tell them to stop walking on the outside of the shoe, the solution is the de-pebble the shoe. Corrective exercises can be a similar path to this pebble analogy. One must look deeper and beyond what we see in our clients, we merely see how they have adapted, not the problem. A Trendelenburg leaning gait is not met with a solution to prescribe a corrective exercise to correct the lean, the solution is to see why the client is reducing the compressive loading across the hip. Stop giving corrective exercises if you are not examining your client. Yes, that means you need to have hands on diagnostic skills. Sorry.

Loading the wrong pattern drives a compensation, and maybe another problem or a compensation to the compensation deeper.

Loading the pattern that is corrective, the one that solves the deficit leading to the gait you see should be your target. Corrective exercises are supposed to be corrective to the problem, not to the gait aberation you see. Without the exam to solidify proper path, corrective exercises often are directed at the things we see, not the aberation that drove what we see. Be part of your clients solution.
If you aren't examining your client, you don't know for certain what you are actually doing.

This is me, Dr. Allen, i am walking in a matter to prove my point.
Do i have a loss of right internal hip rotation (thus the externally rotated limb?). Do i have a swing leg gluteus medius weakness that is allowing me to adduct the limb rendering a mere foot targeting problem? Do i have weak peronei ? A weak glute max ? A right frontal plane drift that i am avoiding by turning my leg out so i can use my quads to help the deficient glutes better block the frontal plane drift ? I could go on an on as to possible causes.
Or do i merely have a pebble in my shoe?
Mic drop.

To give a corrective exercise you have to know what is wrong. That means you have to have the knowledge and the hands on skills to diagnose the "why". So you can prescribe the correct "how".

Shawn Allen, one of the gait guys

Pronation as a shock absorber?

We sometimes (or often) think of pronation as a BAD thing. It's actually a pretty good thing... Along with ankle dorsiflexion, knee flexion, hip flexion and drop of the contralateral pelvis

Check out our quick video on all the shock absorbing mechanisms

Gait is all-encompassing.

Last week we did a presentation on some very classic, yet challenging, gait video case presentations. This slide was a big piece of our presentation.
We discussed that there are volitional and non-volitional movements that accompany the adequate and appropriate postural system control.
If you want to hurt your brain, read this paper.
But in a nutshell what this paper says is that we have a constant switching between steady state cortical neuron discharge and and non-steady state discharge. For example, when we are on a flat road, no obstacles ahead of us, nothing but boring open road, the system sort of runs on an automated program, making limb movements calculated off of a normal unchallenged baseline. But, if there are roots, rocks, curbs, bikes to dodge, puddles to hurdle etc, the volitional and postural systems must change their operation, and alter limb movements based off of those postural systems as we pay attention, and negotiate the obstacles. There is this delicate symphony occurring between automated posture, calculated posture, rhythmic limb movements. In other words, there are volitional, reactionary and anticipatory plans and adjustments occurring in the background at all times.
But, make no mistake, bad, faulty, inefficient motor patterns can become automated if injuries are left, if they are left partially rehabed, if we teach our clients faulty patterns by overloading them and forcing adaptive patterns to inappropriate load or fatigue. These modifications occur deep in the CNS, much in the premotor cortices, and take into account body schema (their correct or distorted perception of where they are, or their limbs are, in space). Build strength or endurance on an altered schema, one that might be present from an old injury, and one will build strength and endurance where one does not want them to go. Properly training clients, offering corrective exercise and the like is far deeper that just asking your client to load and get stronger, unless you wish to assume that their limitations and compensations are unimportant. This takes us right back to the asymmetry debate, which we know so many love to dive into. Asymmetry is the norm of course, just don't be the person creating more of it for your client.

"Adaptive gait control requires constant recalibration of walking pattern to navigate different terrains and environments. For example, motor cortical neurons do not exhibit altered discharge during steady-state locomotion, but altered discharge occurs when the experimental animal has to overcome obstacles. Loops from the motor cortical areas to the basal ganglia and the cerebellum may contribute to this purpose (ie, contribute to accurate and adaptive movement control that requires volition, cognition, attention, and prediction). In contrast, cortical processing seems unnecessary during the automatic execution of locomotion. Rather, high-level processing may occur in the systems between the basal ganglia, cerebellum, and brainstem in the absence of conscious awareness. - TAKAKUSAKI , Neurophysiology of Gait: From the Spinal Cord to the Frontal Lobe

Movement Disorders, Vol. 28, No. 11, 2013

Runners . . . can you hop ?

Photo credit: Lenore Edman

You might think you are a great hopper, but that is because you are never on the same leg hopping forward sequentially. Running is hopping off one good leg, potentially onto another that is just a little less optimal, then back onto a better leg, never fully appreciating a potential asymmetry. 

If you are not assessing your client's hop ability you might be missing some very valuable information. The trouble will be, determining what the deficit is. Telling them they merely have to hop more on the perceived-deficit side is not solving the problem. More does not equal better (unless one is referring to ice cream).

Today, we are in the podcast studio and we will briefly be talking again about the importance of assessing your client's hop ability. Do they have the skill, endurance and strength to hop well, and hop symmetrically?  After all, running is a hopping skill, it is a long jump hop forward in the sagittal plane, followed by an airborne float phase, and an abrupt landing onto the next limb, it is a long jump hop one after the other. If you cannot hop competently, you are at risk.

Skill: Do you have the skill to hop symmetrically ? When you do 15 fast hops forward do the legs feel the same side to side in terms of coordination? or is your foot all over the place "exploring for stability"? Does your knee swim inward, does your hip drift a little into the frontal plane, do you drop the swing leg pelvis ?

Endurance: Can you do it 15 -20 times or more, how about 50? After all, you are about to do a 5mile run (or more !). If you fatigue in any of the components on one leg, your hops are not the same. Get ready for compensation adaptations. So, when you feel something going "funky" wrong in a long run, what do you do? Do you stop, walk and recover or do you keep going ? Many of us are good at ignoring the "blinking check engine light". There is nothing wrong will walking for a bit and giving some fatigued tissue a little time to recover before you start into your run again. We believe many injuries could be avoided if we could get past our "mental moron" issues as runners.

Strength: can you protect the joints and planes from compromise, drift, rotation etc ?

Hopping comprises: proprio, forefoot take off and loading, ankle rocker, a competent tibialis posterior, peroneal group, and achilles-calf complex, knee flexion dampening ability, hip flexion and others . . .

you must be able to stabilize the frontal plane

you must be able to dampen rotational loads

you must be able to keep the knee sagittal

you must control the rate of pronation

you must be able to cyclically convert the foot from flexible to rigid and back again, almost immediately

Just some things to think about before your long run this weekend. We will follow up this post with a long form discussion on an upcoming podcast. We hope you will tune in.

"It is concluded that the fatiguing exercise protocol combined with single-leg hop testing was a reliable method for investigating functional performance under fatigued test conditions. Further, subjects utilized an adapted hop strategy, which employed less hip and knee flexion and generated powers for the knee and ankle joints during take-off, and less hip joint moments during landing under fatigued conditions. The large negative power values observed at the knee joint during the landing phase of the single-leg hop, during which the quadriceps muscle activates eccentrically, indicate that not only hop distance but also the ability to perform successful landings should be investigated when assessing dynamic knee function.

Single-leg hop testing following fatiguing exercise: reliability and biomechanical analysis. Scand J Med Sci Sports. 2006 Apr;16(2):111-20 Augustsson J1, Thomeé R, Lindén C, Folkesson M, Tranberg R, Karlsson J.    https://www.ncbi.nlm.nih.gov/pubmed/16533349