You might think your shoe is doing more to control motion of your foot than it is actually doing.

You might think your shoe is doing more to control motion of your foot than it is actually doing.

"The measurement of rearfoot kinematics by placing reflective markers on the shoe heel assumes its motion is identical to the foot’s motion."
The results of this study revealed that "calcaneal frontal plane ROM was significantly greater than neutral and support shoe heel ROM. Calcaneus ROM was also significantly greater than shoe heel ROM in the transverse and sagittal planes. No change in tibial transverse plane ROM was observed."

It is easy to underestimate the calcaneal ROM across all planes of motion. Motion is going to occur somewhere, hopefully you can help your client control the excessive ROMs that are occurring and causing their symptoms. But just do not think that a shoe is going to markedly help, it might, but let your interventions and your client's feedback on pain lead you.

Calcaneus range of motion underestimated by markers on running shoe heel.
Ryan S. Alcantara'Correspondence information about the author Ryan S. AlcantaraEmail the author Ryan S. Alcantara
, Matthieu B. Trudeau, Eric S. Rohr
Human Performance Laboratory, Brooks Running Company, 3400 Stone Way N, Suite 500, Seattle, WA 98103 United States

You are mostly likely not getting to your big toe at push-off if you are doing this.

You are mostly likely not getting to your big toe at push-off if you are doing this. Look at the shoe wear patterns in the photos below, they are not this runners, but another runner who also has a cross over gait. And, if you have a painful big toe, you will do it as well. Oh, and Head-over-foot related, yup. Read on . . .

Screen Shot 2018-11-17 at 12.45.13 PM.png

Yes, the cross over gait. Yes, when you are into a cross over gait you are most certainly head over foot. And that is most likely not a good thing.

Screen Shot 2018-11-17 at 12.45.50 PM.png

If you are not closer to stacking the hip over the knee, and knee over the foot (like in the photo "SUI" bib runner) you are not likely getting to much of your big toe at terminal stance loading, when you could be getting more power at push off.
Said another way, if you are attacking the ground with the feet closer together, as if you are running on a line (as in the photo) you are going to be more on the outside of the foot (note the lateral foot contact), show a similar wear/loading pattern as in these shoes, and hardly load the medial foot tripod effectively.
Go ahead, walk around your office or home right now . . . . with a very narrow step width and see how little you can load into the big toe-medial foot tripod (note how little effective glute engagement you get as well by the way. there is a reason why there is a limit to the effectiveness of a very narrow step width). Then, walk with a wider step width, note the easier more effective big toe-medial tripod loading, and, note the glutes come into play much more profoundly.
Thus, head over foot/cross over gait is foolish for effective gait. You have a big toe, don't you wish to use it ? One has to find that balance between an economical step width that still allows an effective toe off event in walking and running. A very narrow cross over-style gait does not afford us this.
So, should it be any surprise to any of us that someone with pain in the big toe or medial tripod complex will choose a narrow step width to avoid the painful loading ? No, no surprise there at all.
We have been writing about the cross over gait for 10 years, bringing little pieces of research to the forefront to prove our theories on it as the research presents itself. We first brought it to you with our 3 part video series here. Search our blog, type in "cross over gait" into the search box on the site www.thegaitguys.com and get a LARGE coffee before hand, you are going to be reading for several hours.

https://www.youtube.com/watch?v=LG-xLi2m5Rc
https://www.youtube.com/watch?v=WptxNrj2gCo
https://www.youtube.com/watch?v=oJ6ewQ8YUA

Screen Shot 2018-11-17 at 12.48.24 PM.png
Screen Shot 2018-11-17 at 12.48.17 PM.png

Symptomatic tendons.

Footnotes 7 - Black and Red.png

A symptomatic tendon affects more than the local area it finds itself, it "affects the neuromuscular control on the involved side but not the non-involved side. The muscle–tendon unit on the tendinotic side exhibits a lowered temporal efficiency, which leads to altered CNS control. The altered CNS control is then expressed as an adapted muscle activation pattern in the lower leg". - Yu-Jen Chang and Kornelia Kulig

The rigid flat foot. Why an orthotic may not work well at all.

Just because the foot is flat (arch collapsed) does not mean you have a right to try and lift it !
This is a perfect example of a foot that is troubled. It is a rigid flat foot deformity. This acquired over a long period of time. Sometimes tibialis posterior insufficiency over time finally gives way to an incompetent tib posterior, with eventual arch gradual collapse into a pes planus flat deformity, and then time takes its effect to contracture and shorten tissue and arthritic change makes it permanent.
This arch will no longer lift, it is a rigid pes planus. IT will not tolerate an orthotic, SO DO NOT PRESCRIBE ONE ! Even a mild orthotic lift will feel like a golf ball under this arch.
And, to take this one step further, a rockered shoe is, in part, the right idea, but not when the foot does not sagittally toe off. This foot is permanently locked into a full limb external rotation because of hip arthritic change. The point is that his foot progression angle is 45 degrees++, and the rocker will not work if it cannot rocker in the sagittal plane.
This guy wanted an orthotic, and i would not give it to him, and you shouldn't either. He will wear it for 1 minute and throw it away.

Shawn Allen, the other gait guy

#gait, #anklerocker, #forefootrocker, #footprogression, #archcollapse

Sometimes you may need to put the cart before the horse...The knees, the glutes and reverse engineering ?

Footnotes 7 - Black and Red.jpg

We have talked about looking at things “from the bottom” up in the past, so we can understand things like why the vastus medialis is an external rotator in closed chain as are the semi membranosis and tendinosis. Perhaps we need to think more about this traveling proximally, where the knee effects the glutes. We found this paper looking at women with patello femoral problems and gluteal inhibition. Prospective studies have not found gluteal weakness to be a risk factor for patello femoral problems, but perhaps it is the other way around and patello femoral problems are a risk factor for gluteal weakness? It makes sense, especially if you consider the vastus lateralis like we talk about here and here.

“We hypothesize that muscle inhibition is present in the gluteal muscles of females with PFP compared to healthy controls and it is associated with both decreased subjective function and longer duration of symptoms.”

Dr Ivo Waerlop, one of The Gait Guys

Glaviano NRBazett-Jones DMNorte G. Gluteal muscle inhibition: Consequences of patellofemoral pain? Med Hypotheses. 2019 May;126:9-14. doi: 10.1016/j.mehy.2019.02.046. Epub 2019 Feb 27.

#gait #foot #patellofemoralpain #PFP #quadriceps #thegaitguys #glutes #gluteal muscles

The LAST word....on Lasts

The last (look inside the shoe on top of the shank) is the surface that the insole of the shoe lays on, where the sole and upper are attached).

Shoes are generally board lasted, slip lasted or combination lasted.

A board lasted shoe is very stiff and has a piece of cardboard or fiber overlying the shank and sole (sometimes the shank is incorporated into the midsole or last) . It can be effective for motion control (pronation) but can be uncomfortable for somebody who does not have this problem.

A slip lasted shoe is made like a slipper and is sewn up the middle. It allows great amounts of flexibility, which is better for people with more rigid feet.

A combination lasted shoe has a board lasted heel and slip lasted front portion, giving you the best of both worlds.

When evaluating a shoe, you want to look at the shape of the last (or sole). Bisecting the heel and drawing an imaginary line along the sole of the shoe determines the last shape. This line should pass between the second and third metatarsal. Drawing this imaginary line, you are looking for equal amounts of shoe to be on either side of this line.

Shoes have a straight, curved or semi curved last. The original idea of a curved last (banana shaped shoe) was to help with pronation. A curved last puts more motion into the foot and may force the foot through mechanics that is not accustomed to. Most people should have a straighter lasted shoe.

The shape of a last will effect the biomechanics of the foot. It should match why shape of the foot as closely as possible. Generally speaking, we recommend straighter lasts for folks that have a tendency to overpronate through the midfoot and curvier lasts for folks that have a more rigid foot.

Because the fore foot abducts during mid stance, if the last is curved, the lateral aspect of the foot can rub against the side of the shoe and create blistering of the little toe and if present long enough, a tailors bunion. A general rule of thumb is: "when in doubt, opt for a straighter one"

Dr Ivo Waerlop, one of The Gait Guys

#last #gait #foot #thegaitguys #lastshape #curvedlast #straightlast #gaitanalysis #pronation

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

Luke Ericson is tough as nails.

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 awhile 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 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. 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, the other gait guy

Is your (or your athletes) cleat neutral or in varus?

Cleats are often the athletes primary interface with the ground and are responsible for transmitting the forces from the core and appendicular muscles down to the ground. The construction of the cleat as well as its characteristics (such as a forefoot varus cant in the forefoot, like this one here) can make all the difference in the world in athletic performance.

Dr Ivo Waerlop, one of The Gait Guys

#gait #thegaitguys #forefoot #varus #valgus #gaitanalysis #cleatproblems #cleatconstruction

PRP, platelet-rich plasma for patellar tendinopathy: No more effective than saline (in this first study).

"Combined with an exercise-based rehabilitation program, a single injection of LR-PRP or LP-PRP was no more effective than saline for the improvement of patellar tendinopathy symptoms.:"

*this is the First randomized controlled trial comparing PRP (platelet-rich plasma) injection to saline, for patellar tendinopathy.

Platelet-Rich Plasma for Patellar Tendinopathy: A Randomized Controlled Trial of Leukocyte-Rich PRP or Leukocyte-Poor PRP Versus Saline

Alex Scott, PhD*, Robert F. LaPrade, MD, PhD, Kimberly G. Harmon, MD,

Link: https://journals.sagepub.com/doi/abs/10.1177/0363546519837954?journalCode=ajsb&fbclid=IwAR2p8pj3cugbIafBLaUj8zoaKm3hHyBfIIw6m3rBfDVgBDVKBj73s4jaK30

The problems with some cleats....

Spring is here and Dr Ivo Waerlop of The Gait Guys talks about some common problems seen due to manufacturers defects in cleats and how they can affect athletes. From uppers put on the outsole incorrectly and contributing to and potentiating rearfoot varus and valgus to poor cleat placement affecting the 1st mtp mechanics; they all contribute to athlete performance.

You might think your shoe is doing more to control motion of your foot than it is actually doing.

You might think your shoe is doing more to control motion of your foot than it is actually doing.

"The measurement of rearfoot kinematics by placing reflective markers on the shoe heel assumes its motion is identical to the foot’s motion."
The results of this study revealed that "calcaneal frontal plane ROM was significantly greater than neutral and support shoe heel ROM. Calcaneus ROM was also significantly greater than shoe heel ROM in the transverse and sagittal planes. No change in tibial transverse plane ROM was observed."

It is easy to underestimate the calcaneal ROM across all planes of motion. Motion is going to occur somewhere, hopefully you can help your client control the excessive ROMs that are occurring and causing their symptoms. But just do not think that a shoe is going to markedly help, it might, but let your interventions and your client's feedback on pain lead you.

Calcaneus range of motion underestimated by markers on running shoe heel.
Ryan S. Alcantara'Correspondence information about the author Ryan S. AlcantaraEmail the author Ryan S. Alcantara
, Matthieu B. Trudeau, Eric S. Rohr
Human Performance Laboratory, Brooks Running Company, 3400 Stone Way N, Suite 500, Seattle, WA 98103 United States

Premature heel rise: Part 2

VIDEO: an atypical case of Premature heel rise. A follow up video for yesterdays discussion on the topic.

You should easily see premature heel rise here in this video. We will discuss this case at length with other video projections on our Patreon site next week, if you wish to dive further.

But here you should see, lets focus on the right limb, premature heel rise (again, stick with just watching the right foot/leg). This is, in-part, because this person does not achieve adequate hip extension, you should clearly be able to see that. Loss of terminal hip extension means premature heel rise, no exceptions. Train your eye to see this, you do not need expensive video software to see this.

So, Why inadequate hip extension? Well, just look at the amount of right knee flexion going into terminal stance, it is still heavily flexed and this forces them to prematurely heel rise, avoiding terminal hip extension, and prematurely load the forefoot. Without a knee that extends sufficiently, the hip cannot extend sufficiently, and thus premature heel rise is inevitable. And, trying to solve this issue down at the foot/ankle level is foolish in this case. Stretching this calf day after day until aliens come visit earth will still not be enough stretch time to fix this premature heel rise (ie. get that heel to stay down longer). There is a good reason why this is happening in this person, and it is a neurologic one, one we will discuss on the Patreon site for our Patrons. And, the reason does not matter for the concept I am teaching here today.

For today, you need to be able to see premature heel rise, and know all of the issues behind it, including causes, so that you can direct your phyiscial examination to solve your client's puzzle.
I have included yesterday's post below so you can review and bring this further together.
This is the kind of stuff we will do at Dr. Allen's Friday night Gait Lab, over some beverages. A unique, clinically curious and hungry 25 people need only apply. If you want to get to the next level of your human movement game, this is a way to get there.

Yesterday's post: We know that early/premature heel rise (PHR) leads to premature loading of the forefoot.
We know that premature heel rise (PHR) speeds us through many of the timely mechanical events that need and should occur for to get to safe and effective toe off during walking and running gaits.
This is why there are so many variables that need to be assessed and checked before instituting care to address the premature heel rise, because many times the problem is not even near the heel.
Consider, examine, assess (this is not an exhaustive list either) of causes of PHR
-short calf complex
-short quad (limits hip extension)
- short hip flexors
-anterior pelvis tilt as one's deviated norm posture
- prolonged or excessive rearfoot inversion
-lack of appropriate pronation (sustained supination)
-hallux limitus, rigidus
- weak anterior compartment lower leg
-lack of hip extension/weak glutes
-knee flexion contracture
- neurologic (toe walking gait from youth)
-painful achilles tendon mechanism
- loss of ankle rocker (which has its own long list)
. . . . to name a few

This is why you need to examine your clients, even after a gait analysis. Because, as we like to say, what you see is not your clients gait problem, it is their work around to other mechanical deficits.
After all, telling someone they just need to lengthen/stretch their calf to keep that heel down longer is utterly foolish.

*want to learn more about this stuff, you can join the upcoming Dr. Allen, Friday night Gait Lab series that he will be having in his office one Friday a month, in his Chicagoland office. Stay tuned for that notice. I will take only 25 people per session. We will dive into videos, cases, concepts, white-board rabbit holes, and enjoy some beverages and learn together. Stay tuned. The first 25 to pay and sign up are in !

Shawn Allen, the other gait guy

#gait, #gaitproblems, #gaitanalysis, #heelrise, #PHR, #prematureheelrise, #achilles, #achillestendinitis, #anklerocker, #heelrocker, #forefootpain, #halluxlimitus, #halluxrigidus, #heelpain

Premature heel rise: Part 1

IMG_1603.jpg

We know that early/premature heel rise (PHR) leads to premature loading of the forefoot.
We know that premature heel rise (PHR) speeds us through many of the timely mechanical events that need and should occur for to get to safe and effective toe off during walking and running gaits.
This is why there are so many variables that need to be assessed and checked before instituting care to address the premature heel rise, because many times the problem is not even near the heel.
Consider, examine, assess (this is not an exhaustive list either) of causes of PHR
-short calf complex
-short quad (limits hip extension)
- short hip flexors
-anterior pelvis tilt as one's deviated norm posture
- prolonged or excessive rearfoot inversion
-lack of appropriate pronation (sustained supination)
-hallux limitus, rigidus
- weak anterior compartment lower leg
-lack of hip extension/weak glutes
-knee flexion contracture
- neurologic (toe walking gait from youth)
-painful achilles tendon mechanism
- loss of ankle rocker (which has its own long list)
. . . . to name a few

This is why you need to examine your clients, even after a gait analysis. Because, as we like to say, what you see is not your clients gait problem, it is their work around to other mechanical deficits.
After all, telling someone they just need to lengthen/stretch their calf to keep that heel down longer is utterly foolish.

*want to learn more about this stuff, you can join the upcoming Dr. Allen, Friday night Gait Lab series that he will be having in his office one Friday a month, in his Chicagoland office. Stay tuned for that notice. I will take only 25 people per session. We will dive into videos, cases, concepts, white-board rabbit holes, and enjoy some beverages and learn together. Stay tuned. The first 25 to pay and sign up are in !

Shawn Allen, the other gait guy

#gait, #gaitproblems, #gaitanalysis, #heelrise, #PHR, #prematureheelrise, #achilles, #achillestendinitis, #anklerocker, #heelrocker, #forefootpain, #halluxlimitus, #halluxrigidus, #heelpain

A video primer on foot biomechanics.

Rewind Video Friday.
If you ever were unclear on how the sesamoids, 1st MET and FBH (flexor hallucis brevis) and others party together, this video will help you get up to speed.

As we begin the process of generating new videos, we came across this little gem from 8 years ago. Who is this younger punk ? Its Dr. Allen, showing some foot skills and sharing knowledge, stuff that will serve you well as we move forward with new videos.

https://www.youtube.com/watch?v=TyRE9dReVTE

Neuroma! Triple Threat....

Can you guess why this patient is developing a neuroma on the left foot, between the 3rd and 4th metatarsals?

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IMG_6218.jpg
IMG_6219.jpg

This gal presented to the office with pain in the left foot, in the area she points to as being between the 3rd and 4th metatarsals. It has been coming on over time and has become much worse this spring with hiking long distances, especially in narrower shoes. It is relieved by rest and made worse with activity.

Note the following:

  • She has an anatomical short leg on the left (tibial)

  • internal tibial torsion on the left

  • left forefoot adductus (see the post link below if you need a refresher)

Lets think about this.

The anatomical short leg on the left is causing this foot to remain in relative supination compared the right and causes her to bear weight laterally on the foot.

The internal tibial torsion has a similar effect, decreasing the progression angle and again causing her to bear weight laterally on the foot, compressing the metatarsals together.

We have discussed forefoot adductus before here on the blog. Again, because of the metararsal varus angle, it alters the forces traveling through the foot, pushing the metatarsals together and irritating the nerve root sheath, causing hypertrophy of the epineurium and the beginnings of a neuroma.

In this patients case, these things are additive, causing what I like to a call the “triple threat”.

So, what do we do?

  • give her shoes/sandals with a wider toe box

  • work on foot mobility, especially in descending the 1st ray on the left

  • work on foot intrinsic strength, particularly the long extensors

  • treat the area of inflammation with acupuncture

Dr Ivo Waerlop, one of The Gait Guys

#forefootadductus #metatarsusadductus #neuroma #gaitanalysis #thegaitguys #internaltibialtorsion

Hip flexors do not initiate hip flexon.

We have been saying it in writing and podcasts for years, the hip flexors are limb swing phase PERPETUATORS, not initiators of hip flexion.
It is the elastic response discussed below and the changing of the pelvis obliquity (from posterior positioning to anterior) via the abdominal wall acting on the pelvis-hip interval in conjunction with the stance phase hip musculature that drives hip flexion.
The next time you go after the psoas as a culprit in your meanderings for solutions, because that is what is all over the internet, think bigger, smarter, deeper.

"These experiments also showed that the trailing leg is brought forward during the swing phase without activity in the flexor muscles about the hip joint. This was verified by the absence of EMG activity in the iliacus muscle measured by intramuscular wire electrodes. Instead the strong ligaments restricting hip joint extension are stretched during the first half of the swing phase thereby storing elastic energy, which is released during the last half of the stance phase and accelerating the leg into the swing phase. This is considered an important energy conserving feature of human walking."

Dan Med J. 2014 Apr;61(4):B4823.
Contributions to the understanding of gait control.
Simonsen EB1.

#thegaitguys, #hip, #hipflexors, #pelvismechanics, #swingphase, #gait, #gaitanalysis, #gaitproblems

Knee braces and long legs?

Knee brace fixed at a zero to 5 degree flexion angle, creating a long leg? 

We know that the knee is supposed to flex during stance phase, usually around 20-25 degrees (depending on speed and weight, increases in bot increases the flexion requirement) to create dampening from vertical oscillation of the pelvis. What happens if they cannot flex? This creates a virtual "long leg" on that side this will usually result in:

  • Increased vertical translation of the pelvis upward on the braced side and

  • A compensation to make up for this "long leg; circumduction in this case,  but it could be any of the other compensations that we have talked about in posts here on the blog. 



work arounds? They are tough as each can create their own set of problems

  • allow more flexion in the knee on the braced side (not always possible)

  • place a full length sole lift on the opposite side to make up for the difference

  • use crutches

  • use a skateboard : )

we are sure you have some as well that you would LOVE to share with us

Dr Ivo Waerlop, one of The Gait Guys

#shortleg #LLD #compensations #legbrace #gaitproblem #thegaitguys

 

K ShamaeiGS SawickiAM Dollar Estimation of quasi-stiffness and propulsive work of the human ankle in the stance phase of walking - PloS one, 2013 - journals.plos.org

MORAIS FILHO, Mauro César; REIS, Renata Albertin dos  and  KAWAMURA, Cátia Myuki.Evaluation of ankle and knee movement pattern during maturation of normal gait. Acta ortop. bras. [online]. 2010, vol.18, n.1 [cited  2019-04-25], pp.23-25.

Where do you want to load your foot in relation to your center of mass ?

Screen Shot 2018-11-16 at 6.00.30 PM.png

Who do you want to be ? The guy loading his head over his foot
(narrow step width), or the gal loading the head and COM inside the foot (less narrow step width) ?
It is not hard to guess who is gonna be faster and more powerful from these photos. The lady is stacking the knee over the foot, the hip over the knee and stabilizing the hip and pelvis sufficiently and durably to keep the pelvis level for the next powerful loading step, and the other is flexion collapsing into the stance phase knee, insufficiently loading the hip and thus dropping the opposite side pelvis. He is not stacking the joints, there is a pending cross over (look at the swing leg knee approaching midline with barely any knee spacing, thus guaranteeing a cross over step or at the very least a very narrow step width.)
Sure, some one is going to say one is a distance runner and the other is a sprinter. Yes, and our point is that the sprinter is not head-over-foot, the one with all the highly suspect flaws is head over foot ! Wider step width means more glutes. Go ahead, walk around right now with a very narrow step width and see how little efficient glute contraction you get, then walk with a notably wider step width, and you will see wider means more glutes. Keep your COM moving forward, not oscillating back and forth sideways over each stance foot, that is a power leak.

Screen Shot 2018-11-16 at 6.00.11 PM.png

The distance runner is showing sloppy in technique. Say what you want, but one of these runners is weak and very likely at greater risk for injury, the other is strong and durable, and likely at less risk for injury.
If you ask us, but what do we know . . . .
So, again, was ask . . . . which one do you want to be ?