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

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

The “Standing on Glass” Static Foot/Pedograph... PART 2

The “Standing on Glass” Static Foot/Pedograph... PART 2
We hope you find this case presentation dialogue interesting.

Screen Shot 2019-01-13 at 7.51.15 PM.png

* note: This is a static assessment dialogue. One cannot, and must not, make clinical decisions from a static assessment. As in all assessments, information is taken in, digested and them MUST be confirmed, denied and/or at the very least, folded into a functional and clinically relevant assessment of the client before the findings are accepted, dismissed and acted upon.

Here is the case . . .

Part 2: “Standing on Glass” Static Foot/Pedograph Assessment

* note (see warning at bottom): This is a static assessment dialogue. One cannot, and must not, make clinical decisions from a static assessment. The right and left sides are indicated by the R and L circled in pink. There are 4 photos here today.

Blue lines: Last time we evaluated possible ideas on the ORANGE lines here, it would be to your advantage to start there.

We can see a few noteworthy things here in these photos. We have contrast-adjusted the photo so the pressure areas (BLUE) are more clearly noted. There appears to be more forefoot pressure on the right foot (the right foot is on the readers left), and more rearfoot pressure on the left (not only compare the whiteness factor but look at the displacement of the calcaneal fat pad (pink brackets). There is also noticeably more lateral forefoot pressure on the left. There is also more 3-5 hammering/flexion dominance pressure on the left. The metatarsal fat pad positioning (LIME DOTS represent the distal boundary) is intimately tied in with the proper lumbrical muscle function (link) and migrates forward toward the toes when the flexors/extensors and lumbricals are imbalanced. We can see this fat pad shift here (LIME DOTS). The 3-5 toes are clearly hammering via flexor dominance (LIME ARROWS), this is easily noted by visual absence of the toe shafts, we only see the toe pads. Now if you remember your anatomy, the long flexors of the toes (FDL) come across the foot at an angle (see photo). It is a major function of the lateral head of the Quadratus plantae (LQP) to reorient the pull of those lesser toe flexors to pull more towards the heel rather than on an angle. One can see that in the pressure photos that this muscle may be suspicious of weakness because the toes are crammed together and moving towards the big toe because of the change in FDL pull vector (YELLOW LINES). They are especially crowding out the 2nd toe as one can see, but this can also be from weakness in the big toe, a topic for another time. One can easily see that these component weaknesses have allowed the metatarsal fat pad to migrate forward. All of this, plus the lateral shift weight bearing has widened the forefoot on the left, go ahead, measure it. So, is this person merely weight bearing laterally because they are supinating ? Well, if you read yesterday’s blog post we postulated thoughts on this foot possibly being the pronated one because of its increased heel-toe and heel-ball length. So which is it ? A pronated yet lateral weight bearing foot or a normal foot with more lateral weight bearing because of the local foot weaknesses we just discussed ? Or is it something else ? Is the problem higher up, meaning, are they left lateral weight bearing shift because of a left drifted pelvis from weak glute medius/abdominal obliques ? Only a competent clinical examination will enlighten us.

Is the compensation top-down or bottom up, or both in a feedback cycle trying to find sufficient stability and mobility ? These are all viable possibilities and you must have these things flowing freely through your head during the clinical examination as you rule in/rule out your hands-on findings. Remember, just going by a screen to drive prescription exercises from what you see on the movement screen is not going to necessarily fix the problem, it could in fact lead one to drive a deeper compensation pattern.

Remember this critical fact. After an injury or a long standing problem, muscles and motor patterns jobs are to stabilize and manage loads (stability and mobility) for adequate and necessary movement. Injuries leave a mark on the system as a whole because adaptation was necessary during the initial healing phase. This usually spills over during the early movement re-introduction phase, particularly if movement is reintroduced too early or too aggressively. Plasticity is the culprit. Just because the injury has come and gone does not mean that new patterns of skill, endurance, strength (S.E.S -our favorite mnemonic), stability and mobility were not subsequently built onto the apparently trivial remnants of the injury. There is nothing trivial if it is abnormal. The forces must, and will, play out somewhere in the body and this is often where pain or injury occurs but it is rarely where the underlying problem lives.

Come back tomorrow. We will try to bring this whole thing together, but remember, it will just be a theory for without an exam one cannot prove which issues are true culprits and which are compensations. Remember, what you see is often the compensatory illusion, it is the person moving with the parts that are working and compensating not the parts that are on vacation. See you tomorrow friends !

Shawn and ivo, the gait guys

* note: This is a static assessment dialogue. One cannot, and must not, make clinical decisions from a static assessment. As in all assessments, information is taken in, digested and then MUST be confirmed, denied and/or at the very least, folded into a functional and clinically relevant assessment of the client before the findings are accepted, dismissed and acted upon. As we always say, a gait analysis or static pedograph-type assessment (standing force plate) is never enough to make decisions on treatment to resolve problems and injuries. What is seen and represented on either are the client’s strategies around clinical problems or compensations. Today’s photo and blog post are an exercise in critical clinical thinking to get the juices flowing and to get the observer thinking about the client’s presentation and to help open up the field to questions the observer should be entertaining. The big questions should be, “why do i see this, what could be causing these observances ?”right foot supinated ? or more rear and lateral foot……avoiding pronation ?


The “Standing on Glass” Static Foot/Pedograph Assessment: Part 1

Screen Shot 2019-01-13 at 7.42.41 PM.png

The “Standing on Glass” Static Foot/Pedograph... PART 1
We hope you find this case presentation dialogue interesting.

* note: This is a static assessment dialogue. One cannot, and must not, make clinical decisions from a static assessment. As in all assessments, information is taken in, digested and them MUST be confirmed, denied and/or at the very least, folded into a functional and clinically relevant assessment of the client before the findings are accepted, dismissed and acted upon.

The “Standing on Glass” Static Foot/Pedograph Assessment: Part 1

* note: This is a static assessment dialogue. One cannot, and must not, make clinical decisions from a static assessment. As in all assessments, information is taken in, digested and them MUST be confirmed, denied and/or at the very least, folded into a functional and clinically relevant assessment of the client before the findings are accepted, dismissed and acted upon. As we always say, a gait analysis or pedograph-type assessment is never enough to make decisions on treatment to resolve problems and injuries. What is seen and represented on either are the client’s strategies around clinical problems or compensations. Today’s photo and blog post are an exercise in critical clinical thinking to get the juices flowing and to get the observer thinking about the client’s presentation and to help open up the field to questions the observer should be entertaining. The big questions should be, “why do i see this, what could be causing these observances ?”

* note the right and left sides by the R and L circled in pink.

ORANGE lines: The right foot appears to be shorter, or is it that the left is longer (see the lines and arrows drawing your attention to these differences)? A shorter foot could be represented by a supinated foot (if you raise the arch via the windlass mechanism you will shorten the foot distance between the rear and forefoot). A longer foot could be represented by a more pronated foot. Is that what we have here ? There is no way to know, this is a static presentation of a client standing on glass. What we should remember is that the goal is always to get the pelvis square and level. If an anatomically or functionally short leg is present, the short leg side MAY supinate to raise the mortise and somewhat lengthen the leg. In that same client, they may try to meet the process part way by pronating the other foot to functionally “shorten” that leg. Is that what is happening here ? So, does this client have a shorter right leg ? Longer left ? Do you see a plunking down heavily onto the right foot in gait ? Remember, what you see is their compensation. Perhaps the right foot is supinating, and thus working harder at the bottom end of the limb (via more supination), to make up for a weak right glute failing to eccentrically control the internal spin of the leg during stance phase ? OR, perhaps the left foot is pronating more to drive more internal rotation on the left limb because there is a restricted left internal hip rotation from the top ? Is the compensation top-down or bottom up ? These are all viable possibilities and you must have these things flowing freely through your head during the clinical examination as you rule in/rule out your hands-on findings. Remember, just going by a FMS-type screen to drive prescription exercises from what you see on a movement screen is not going to necessarily fix the problem, it could in fact lead one to drive a deeper compensation pattern. You can be sure that Gray Cook’s turbo charged brain is juggling all of these issues (and more !) when he sees a screen impairment, although we are not speaking for him here.

Remember this critical fact. After an injury or a long standing problem, muscles and motor patterns jobs are to stabilize and manage loads (stability and mobility) for adequate and necessary movement. Injuries leave a mark on the system as a whole because adaptation was necessary during the initial healing phase. This usually spills over during the early movement re-introduction phase, particularly if movement is reintroduced too early or too aggressively. Plasticity is the culprit. Just because the injury has come and gone does not mean that new patterns of skill, endurance, strength (S.E.S -our favorite mnemonic), stability and mobility were not subsequently built onto the apparently trivial remnants of the injury. There is nothing trivial if it is abnormal. The forces must, and will, play out somewhere in the body and this is often where pain or injury occurs but it is rarely where the underlying problem lives.

Come back tomorrow, where we will open your mind into the yellow, pink, blue and lime markings on the photo. Are the hammering toes (lime) on the left a clue ? How about the width of the feet (yellow) ? The posturing differences of the 5th toe to the lateral foot border ? What about the static plantar pressure differences from side to side (blue)? Maybe, just maybe, we can bring a logical clinical assumption together and then a few clinical exam methods to confirm or dis-confirm our working diagnostic assumption. See you tomorrow friends !

Shawn and ivo, the gait guys

Here is the case link.......

https://thegaitguys.tumblr.com/post/99409232289/the-standing-on-glass-static-footpedograph?fbclid=IwAR3gd3d81Gwt3ywAB7BcTwXqST2Z_5nmieODzSb8rJQYBcJFhTs6rS_9auA

Pronation anyone? Coupling? Walking Speed? How do they relate?

We have talked many times here on TGG about pronation, supination, overpronation, asymmetrical pronation, and more.

When most people think of pronation, they think of midfoot pronation, or pronation about the subtalar or transverse tarsal joints. Pronation can actually occur about any articulation or bone, but with respect to the foot, we like to think of rearfoot (ie. talo-calcaneal), midfoot (talo-navicular) and forefoot (transverse tarsal). The question is why does this matter?

Pronation, with respect to the foot, is defined as a combination of eversion, abduction and dorsiflexion (see picture attached) which results in flattening of the planter vault encompassing the medial and lateral longitudinal arches. In a normal gait cycle, this begins at initial contact (heel strike) and terminates at midstance, lasting no more than 25% of the gait cycle.

In a perfect biomechanical world, shortly following initial contact with the ground, the calcaneus should evert 4-8 degrees, largely because the body of the calcaneus is lateral to the longitudinal axis of the tibia. This results in plantar flexion, adduction and eversion of the talus on the calcaneus, as it slides anteriorly. At this point, there should be dorsiflexion of the transverse tarsal (calcaneo-cuboid and talo-navicular joints). Due to the tight fit of the ankle mortise and its unique shape, the tibial rotates internally (medially). This translates up the kinetic chain and causes internal rotation of the femur, which causes subsequent nutation of the pelvis and extension of the lumbar spine. This should occur in the lower kinetic chain through the 1st half of stance phase. The sequence should reverse after the midpoint of midstance, causing supination and creating a rigid lever for forward propulsion.

Pronation, along with knee and hip flexion, allow for shock absorption during throughout the 1st half of stance phase. Pronation allows for the calcaneo-cuboid and talo-navicular joint axes to be parallel making the foot into a mobile adaptor so it can contour to irregular surfaces, like our hunter gatherer forefathers used to walk on before we paved the planet. Problems arise when the foot either under pronates (7 degrees valgus results in internal tibial rotation), resulting in poor shock absorption or over pronates (> 8 degrees or remains in pronation for greater than 50% of stance phase).

This paper talks about how foot and ankle pathologies have effects on other articulations in the foot. They looked at stance phase of gait in 14 people without pathology at 3 different walking speeds. they found:

coupling relationships between rear foot inversion and hallux plantar flexion and rear foot eversion with hallux dorsiflexion.... When the rear foot everts (as it does as discussed above) during pronation from initial contact to mid stance , the hallux should be extending AND when the rear foot everts, as it should from mid stance to terminal stance/pre swing, the hallux should be plantar flexing to get the 1st ray down to the ground

medial (internal) rotation of there leg was accompanied by mid foot collapse (read pronation) and lateral (external) rotation with mid foot elevation (read supination).... Because of the shape of the talar dome and shape of the talo calcaneal facet joints, the talus plantar flexes, everts and adducts from initial contact to mid stance, and dorsiflexes, inverts and adducts from mid stance to terminal stance/ pre swing

walking speed significantly influenced these coupling relationships....meaning that the faster we go, the faster these things must happen and the greater degree that the surrounding musculature and associated cortical control mechanisms must act

So, when these relationships are compromised, problems (or more often, compensations) ensue. Think about these relationships and the kinetics and kinematics the next time you are studying someones gait.

Dr Ivo Waerlop, one of The Gait Guys

Dubbeldam R1, Nester C, Nene AV, Hermens HJ, Buurke JH. Kinematic coupling relationships exist between non-adjacent segments of the foot and ankle of healthy subjects.Kinematic coupling relationships exist between non-adjacent segments of the foot and ankle of healthy subjects.Gait Posture. 2013 Feb;37(2):159-64. doi: 10.1016/j.gaitpost.2012.06.033. Epub 2012 Aug 27

cool video on our blog to go with this post:

https://www.thegaitguys.com/thedailyblog/2018/8/7/what-do-you-know-about-pronation-and-supination

#gaitanalysis #thegaitguys #pronation #couplingrelationshipsandgait #pronation

The loads are going to go somewhere.

You cannot change one thing, and not expect the other parts to change, have to adapt, and possibly complain at some point.
The loads are going to go somewhere.

Too much pronation means the arch may be reduced in height, but it also means that the first ray complex (the 1-2 metatarsals essentially) is dorsiflexing more than normal. This means they will not likely get to their adequate plantarflexion by the time the foot is ready to heel rise and toe off at supination. In other words, if you have pronated and dorsiflexed too long and too much, you will eat up the time you needed to plantarlfex and supinate.
This means that "Increased foot pronation may compromise ankle plantarflexion moment during the stance phase of gait, which may overload knee and hip."-Resende et al

If you cannot plantarflex the foot-ankle complex sufficiently, or in a timely manner, you should understand that you are carrying this fault forward while moving into heel rise during the forefoot rocker stance phase of gait, and you are doing it over a less stable, less rigid foot-ankle complex because it is still in relative pronation. This means you are placing higher propulsive loads over an unprepared ankle-foot complex. This means different/altered posterior compartment function, which can mean altered knee and hip function. Sagittal plane function, to name the most obvious, will have to create and endure compensatory loads. Sure, they may be fine for a time, but perhaps there will be a cost over time. Now, many might say, "if it is not a problem now, it is not a problem", let them build robustness on their chosen pattern; that can be very hopeful and shortsighted thinking in our opinion. Why not change things that are obviously aberrant and build robustness on a pattern and correction that is suspected to be more sound? This can be a cyclical argument that no one wins, EVER, we all see it all the time. After all, the arguments become silly after time, and we resist our own silly comments like "well, why change the oil in your car right now, nothing bad is happening at this time. Or, well that front right tire, though bald and nearly flat, is still rolling along so why bother changing it out?" But that stuff gets no one anywhere, other than pissed off, so we hold back. The debate never gets furthered along, because no one can see the future.

So, we will leave this rant with this thought, we cannot change one thing, and not expect the other parts to change, have to adapt. And adaptation can be both good OR bad. Or maybe we should say, good AND bad.
The loads are going to go somewhere. Lets leave it at that.

photo: credit pixabay.com

Gait Posture. 2018 Oct 23;68:130-135. doi: 10.1016/j.gaitpost.2018.10.025. [Epub ahead of print]
Effects of foot pronation on the lower limb sagittal plane biomechanics during gait.
Resende RA1, Pinheiro LSP2, Ocarino JM3.

Increased unilateral foot pronation and its effects upward into the chain.

Increased unilateral foot pronation affects lower limbs and pelvic biomechanics during walking. Nothing earth shaking here, we should all know this as fact. When a foot pronates more excessively, the arch can flatten more, and this can accentuate a leg length differential between the 2 legs. But it is important to note that when pronation is more excessive, it usually carries with it more splay of the medial tripod as the talus also excessively plantarflexes, adducts and medially rotates. This action carries with it a plantar-ward drive of the navicular, medial cuneiforms and medial metatarsals (translation, flattening of the longitudinal arch). These actions force the distal tibia to follow that medially spinning and adducting talus and thus forces the hip to accommodate to these movements. And, where the hip goes, the pelvis must follow . . . . and so much adaptive compensations.
So could a person say that sometimes a temporary therapeutic orthotic might only be warranted on just one foot ? Yes, of course, one could easily reason that out.
-Shawn Allen, one of The Gait Guys

#gait, #gaitanalysis, #gaitproblems, #thegaitguys, #LLD, #leglength, #pronation, #archcollapse, #orthotics, #gaitcompensations, #hippain, #hipbiomechanics

Gait Posture. 2015 Feb;41(2):395-401. doi: 10.1016/j.gaitpost.2014.10.025. Epub 2014 Nov 3.
Increased unilateral foot pronation affects lower limbs and pelvic biomechanics during walking.
Resende RA1, Deluzio KJ2, Kirkwood RN3, Hassan EA4, Fonseca ST5.

When the Windlass is lost.

When the Windlass is lost.
Here, this case again (hallux amputation), when the Windlass is lost or at the very least, impaired, what holds up the arch?
Without the winding of the plantar fascia through hallux dorsiflexion (toe extension) and without the FHL (flexor hallucis longus) we lose major engineering advantages to lift/support the arch and control pronation variables.
So what is left ?
Tibialis posterior, tibialis anterior, peroneus longus, mostly, are what is left. So when these guys are suffering (ie, tendinopathy etc) it could be due to the other previously mentioned engineering marvels being impaired.

It is a team effort to keep the foot healthy and functioning without expressible pathology.

*note the heavy flexion attempts of the 2nd toe, the next soldier in line, no surprise there.
Now you should realize why you see this 2nd toe over-flexion attempts when even an existing, yet incompetent, hallux is present.

This slide is part of a new presentation, one we will be doing a WEBEX on that you can all join in on, and it will be a new presentation for our onlineCE Wednesday night seminars.

Now, go read this dudes blog, inspirational journey through big toe cancer. Thanks for sharing your story Kevin, and your case photos. (PS: presentation is almost done, so i will be in touch soon so we can go over it and collaborate).
https://www.theagecoach.com/

#gait, #gaitanalysis, #gaitproblems, #thegaitguys, #gaitcompensations, #halluxamputation, #windlassmechanism, #halluxdorsiflexion, #pronation, #FHB, #FHL, #hammertoes, #theagecoach

When your calf is weak, things can dorsiflex too much sometimes.

When your calf is weak, things can dorsiflex too much sometimes. Maybe this is why you have Achilles tendinopathy. Maybe.

When we run, we either heel strike, midfoot strike, or forefoot strike. The literature is pretty clear on this now, that any one of them is not better than the other and there are many variables that need to be taken into consideration (even though many folks, who stopped reading the studies long after the barefoot craze began, will proclaim at the grave of their mother that rearfoot strike and anything but zero drop shoes are the root of all evil).

However, if you are a forefoot striker, the calf complex must be durable, strong and have enough endurance that when the foot strike occurs, that over time the complex does not allow the heel drop to become excessive or uncontrolled to the point that the achilles tendon proper exceeds its capacity to tolerate the drop, the stretch load capacity. It is more complex than this, because when the heel drops too much, too far, too fast and the arch is not durable enough, the metatarsals may dorsiflex too much and compromise the arch and stiffness of the midfoot, this can also have its complications. A weak calf can impact the rest of the foot. Remember, when the forefoot is engaged on the ground, and the heel drops in an uncontrolled fashion, we are increasing ankle dorsiflexion too, and this may not be welcomed during a stance phase of running where we are hoping for sufficient foot stiffness to load across it and propulse off of it.

This study showed that "analysis revealed that male recruits with lower plantar flexor strength and increased dorsiflexion excursion were at a greater risk of Achilles tendon overuse injury".

Intrinsic risk factors for the development of achilles tendon overuse injury: a prospective study.

Mahieu NN, et al. Am J Sports Med. 2006.

Adaptations and compensations.

Screen Shot 2018-10-25 at 10.54.01 AM.png

. . . the entire system has to adapt to that deficiency. That means compensation. Now, does adding strength to that asymmetry (compensation) have a consequence. Most likely. Will it lead to injury? That is the question.

We are going to keep pounding sand on this one because we believe this is important.
All too often people are working out and strengthening their systems, and that is good. But, if they are strengthening a system that is asymmetric or strengthening a faulty pattern (clearly, as in too much arch collapse) they are likely overburdening the hierarchical system and a component of the chain of that system.
Now, many are going to argue, and we know who those folks are, they are going to argue that if the movement is not painful, if the posturing of the load is not painful, then it is not a problem. Sure, and that is easy to say, but there is no proof they are right either. And, we are not saying we are stonewalled right either, but we are trying to be logical with what we know and what some of the research says (yes, that fits our bias). But our eyes are open and we hear the arguments from the other side, but those arguments come from a crystal ball in our opinion. Truthfully, no one has that crystal ball and can see into the future to see if one side of this argument has any more "legs" to it.
However, we know that . . .

"Human movement is initiated, controlled and executed in a hierarchical system including the nervous system, muscle and tendon. If a component in the loop loses its integrity, the entire system has to adapt to that deficiency. Achilles tendon, when degenerated, exhibits lower stiffness. This local mechanical deficit may be compensated for by an alteration of motor commands from the CNS. These modulations in motor commands from the CNS may lead to altered activation of the agonist, synergist and antagonist muscles."- Chang and Kulig

So, when we see a pattern of loading that is aberrant, and especially when it is most likely playing into a client's painful presentation, it is an easier sell on the thought-arguments above. We know that the entire system has to adapt to deficiencies. It is how we are synergistically built. We have redundancies build into us that protect us. Compensation is part of the redundancy. So, does adding strength to that asymmetry (compensation) have a consequence? Most likely it does, in our opinion. Why allow an area to undergo more loading than we know it should, (ie. valgus knee loading) even if it is non-painful to a client ? Will it lead to eventual injury or pain? That is the question. But we have picked our side of the story, for now, until proven otherwise, and we work from that side of the line. For now.

"yet" is a powerful looming word.
When adding strength takes someones pain away, it doesn't mean you fixed them. It likely means you helped them adapt and protect and better negotiate the loads. However, it also does not mean that your instruction did not build a layer of initial protective strength that will not have a cost further down the road because it wasn't the right medicine for the problem.
When your cars alignment is off, and it is pulling the car to the right towards the ditch, pulling harder to the left on the steering wheel keeps the alignment aberrancy, and the ditch at bay. But nothing was fixed. You adapted and compensated. The problem is still sitting there. And you will get used to the adapted and compensated pattern of steering wheel pull in time. Until the next thing occurs. Maybe the tire will start to chirp in time, the treads silently wear unevenly, and maybe it will be your left shoulder that chirps at you, and not the car.

The squeaky wheel may get the grease, but the misaligned tire is ignored.

Shawn and Ivo, the gait guys

J Physiol. 2015 Aug 1; 593(Pt 15): 3373–3387.
Published online 2015 Jun 30. doi: 10.1113/JP270220
The neuromechanical adaptations to Achilles tendinosis
Yu-Jen Chang and Kornelia Kulig

#gait, #thegaitguys, #gaitcompensations, #gaitproblems, #compensations, #running, #walking, #genuvalgus, #pronation, #CNS, #synergist

"You do not have a shoe problem, you have a "thing in the shoe problem", meaning, it is you."

We say this so often in our offices.
"You do not have a shoe problem, you have a "thing in the shoe problem", meaning, it is you."
Translation: compromised mechanics leading to tissue overloading.
But we all have to strongly consider that injury is a result of the loading you have not trained gradually into, failure to adapt and accommodate, excessive mileage without adequate tissue recovery,

From the article:
"So Napier and co-author Richard Willy from the University of Montana reviewed the highest-quality research featuring randomized controlled trials and systematic reviews.
"What we see is that there's really no high-level evidence that any running shoe design can prevent injuries," Napier said."

Now, to be honest, in our (the gait guys) opinion, there are times we do recommend a change in the foot wear for a client, and it is often because it appears to be working against someone mechanics and is a contributory factor in their injury or complaint. And sometimes that shoe recommendation is a temporary one, and sometimes a permanent one. We can use a shoe to help us get to a better/faster end point. After all, when we sprain an ankle sometime a brace or crutches are helpful and protective, of temporary value. A wisely chosen shoe can act the same if we are dealing with an acute achilles tendinopathy or a painful bunion for example. And in those cases we might recommend a shoe that can give us an assist. Sometime, when appropriate perhaps it is a shoe with a stronger medial post, perhaps one with a higher or lower heel drop/delta, or more or less stack height, or perhaps a mid/forefoot rocker built into the shoe. The truth is, people come in with functional or "fixed" pathology and sometimes pairing up a shoe to help us around some conflicting biomechanics can be temporarily, and sometimes permanently, helpful. But, the shoe is never the only answer, a wise clinician has many things they can utilize, all the way up the kinetic chain sometimes.
The more you know, the better you can assist someone.

Shawn Allen, one of the gait guys

#Nigg, #barefoot, #shoes, #stackheight, #heeldrop, #achillestendinitis, #bunion, #pronation, #supination, #running, #gait, #thegaitguys, #gaitanalysis, #gaitproblems, #gaitcompensation

Can the design of a running shoe help prevent injury? A B.C. researcher says he has the answer

Kelly Crowe · CBC News · Posted: Dec 15, 2018 9:00 AM ET

https://www.cbc.ca/news/health/running-shoe-injury-prevention-second-opinion-1.4947408?fbclid=IwAR3XaGPdgfQ68wj2N0tHqIamDdpYuxTIIL2LeudUd-doYN8YqQrIZI9-s9E

Do you have dorsal (top) foot pain? Think you are tying your shoes too tightly?

Do you have dorsal (top) foot pain, at the peak of the arch? Think you are tying your shoes too tightly and that is the cause? Do you have pain over the dorsal or plantar mid foot on heel rise or jumping/landing or going up stairs ?

Just because you raise your heel and load the ball of the foot does not necessarily mean you have adequately plantarflexed the 1st metatarsal and loaded it soundly/stable with the medial tarsal bone. Heel rise, and thus loading onto the medial foot tripod, must be met with ample, stable, durable, 1st metatarsal plantarflexion and the associated medial tarsal bones. Also, without this, loading of the sesamoids properly cannot occur, and pain may ensue.

The first ray complex can be delicate in people who are symptomatic. In some people who do not have a good tibialis posterior-peroneus sling mechanism working harmoniously, in conjunction with a competent arch tripod complex to achieve a compentent arch complex (ie, EDL, EHL, tib anterior and some of the other foot intrinsics) this tarsometatarsal interval can become painful and instead of the 1st ray complex being stable and plantarflexing as the heel departs and the 1st ray begins taking load, it may not do so in a stable plantarflexed posturing. In some people it can momentarily dorsiflex as the arch subtly collapses (when it should be stable and supinated in heel rise).

"Subtle hypermobility of the first tarsometatarsal joint can occur concomitantly with other pathologies and may be difficult to diagnose. Peroneus Longus muscle might influence stability of this joint. Collapse of the medial longitudinal arch is common in flatfoot deformity and the muscle might also play a role in correcting Meary's angle."-Duallert et al

Soon, I hope to show you a video of how to watch for this problem, how to train it properly, how we do it in my office.
Dr. Allen

https://www.ncbi.nlm.nih.gov/pubmed/27015031

Clin Biomech (Bristol, Avon). 2016 May;34:7-11. doi: 10.1016/j.clinbiomech.2016.03.001. Epub 2016 Mar 10.

The influence of the Peroneus Longus muscle on the foot under axial loading: A CT evaluated dynamic cadaveric model study.

Dullaert K1, Hagen J2, Klos K3, Gueorguiev B4, Lenz M5, Richards RG6, Simons P7.

What do you know about pronation and Supination?

We have talked many times here on TGG about pronation, supination, overpronation, asymmetrical pronation, and more. 

When most people think of pronation, they think of midfoot pronation, or pronation about the subtalar or transverse tarsal joints. Pronation can actually occur about any articulation or bone, but with respect to the foot, we like to think of rearfoot (ie. talo-calcaneal), midfoot (talo-navicular) and forefoot (transverse tarsal). The question is why does this matter?

Pronation, with respect to the foot, is defined as a combination of eversion, abduction and dorsiflexion  (see picture attached) which results in flattening of the planter vault encompassing the medial and lateral longitudinal arches. In a normal gait cycle, this begins at initial contact (heel strike) and terminates at midstance, lasting no more than 25% of the gait cycle.

In a perfect biomechanical world, shortly following initial contact with the ground, the calcaneus should evert 4-8 degrees, largely because the body of the calcaneus is lateral to the longitudinal axis of the tibia. This results in plantar flexion, adduction and eversion of the talus on the calcaneus, as it slides anteriorly. At this point, there should be dorsiflexion of the transverse tarsal (calcaneo-cuboid and talo-navicular joints). Due to the tight fit of the ankle mortise and its unique shape, the tibial rotates internally (medially). This translates up the kinetic chain and causes internal rotation of the femur, which causes subsequent nutation of the pelvis and extension of the lumbar spine.  This should occur in the lower kinetic chain through the 1st half of stance phase. The sequence should reverse after the midpoint of midstance, causing supination and creating a rigid lever for forward propulsion.

Pronation, along with knee and hip flexion, allow for shock absorption during throughout the 1st half of stance phase. Pronation allows for the calcaneo-cuboid and talo-navicular joint axes to be parallel making the foot into a mobile adaptor so it can contour to irregular surfaces, like our hunter gatherer forefathers used to walk on before we paved the planet. Problems arise when the foot either under pronates (7 degrees valgus results in internal tibial rotation), resulting in poor shock absorption or over pronates (> 8 degrees or remains in pronation for greater than  50% of stance phase).

This paper talks about how foot and ankle pathologies have effects on other articulations in the foot. They looked at stance phase of gait in 14 people without pathology at 3 different walking speeds. they found

  • coupling relationships between rear foot inversion and hallux plantar flexion and rear foot eversion with hallux dorsiflexion

When the rear foot everts (as it does as discussed above) during pronation from initial contact to mid stance , the hallux should be extending AND when the rear foot everts, as it should from mid stance to terminal stance/pre swing, the hallux should be plantar flexing to get the 1st ray down to the ground

  • medial (internal) rotation of there leg was accompanied by mid foot collapse (read pronation) and lateral (external) rotation with mid foot elevation (read supination)

Because of the shape of the talar dome and shape of the talo calcaneal facet joints, the talus plantar flexes, everts and adducts from initial contact to mid stance, and dorsiflexes, inverts and adducts from mid stance to terminal stance/ pre swing

  • walking speed significantly influenced these coupling relationships

meaning that the faster we go, the faster these things must happen and the greater degree that the surrounding musculature and associated cortical control mechanisms must act

 So, when these relationships are compromised, problems (or more often, compensations) ensue. Think about these relationships and the kinetics and kinematics the next time you are studying someones gait. 

Here is a fun video talking about some of these relationships. 

 

Dubbeldam R1, Nester CNene AVHermens HJBuurke JH. Kinematic coupling relationships exist between non-adjacent segments of the foot and ankle of healthy subjects.Kinematic coupling relationships exist between non-adjacent segments of the foot and ankle of healthy subjects.Gait Posture. 2013 Feb;37(2):159-64. doi: 10.1016/j.gaitpost.2012.06.033. Epub 2012 Aug 27.

 

Part 2: The amputated hallux & the complex biomechanical fall-out from it.

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Last week we promised Part 2 to this case, the amputated big toe.
Here is part 2. These are the complicated biomechanical fall-outs, so grab a big mug o' coffee and have at it !

In review, this person (all photos and case premissioned in swap for insight) had the distal hallux removed because of a progressive melanoma on the big toe. Can you believe that ! This is one more reminder that the sun and regular dermatologist screenings are wise.
This person had a complaint of progressing right gluteal and QL pain, spasm, tone and some persistent pain now in the 2nd metatarsal as well as some shoe challenges. We discuss this case briefly in and upcoming podcast, #139 or #140 we believe.

Screen Shot 2018-08-10 at 8.10.19 AM.png

Before we add our final thoughts to this case, lets cap our post from last week.

-Without the hallux, we cannot wind up the windlass and shorten the distance between the first metatarsal and heel, thus the arch will splay (more permanently over time we suspect) and we cannot optimize the arch height.
This will promote more internal spin on that limb because of more midfoot pronation and poor medial foot tripod stabilization.
- More internal limb spin means more internal hip spin, and more demand (which might not be met at the glute level) and thus loads that are supposed to be buffered with hip stabilization, will likely be transferred into the low back, and or into the medial knee. Look for more quad protective tone if they cannot get it from the glutes. Troubles arise when we try to control the hip from quadriceps strategies, it is poorly postured to do so, but people do it everyday, *hint: most cyclists and distance runners to a large degree).
- anterior pelvis posturing on the right, perhaps challenging durability of the lower abdominals, hence suspect QL increased protective tone, possible low back tightness or pain depending on duration of activities
- These factors are likely related to his complaints in the right gluteal and low back/QL area.

Now, onto our next thoughts.

- when the hallux is incompetent, in this case absent, there are few other choices to gain forefoot purchase on the ground other than more flexion gripping of the 2nd toe (then the 3rd, then 4th). This is a progressing "searching" phenomenon for forefoot stability and without the function of the big fella, the 2nd toe will begin a hammering phenomenon, often, but not always. We would not be surprised to see hammer toe development in this case, but this person is now very aware of it, and can at least now fight that battle with increased awareness. There is some mild evidence of this on the side lateral photo.

- We are happy to see that the proximal phalange was spared. The adductor hallucis is inserted medially there, and this will help to reduce bunion generation risk (medial metatarsal drift). Comparing the photo and the radiograph is a great example of how far back/proximal the 1st MTP joint is. One could easily assume that the entire hallux was resected from the photo, but the radiograph shows otherwise.

Screen Shot 2018-08-10 at 8.22.36 AM.png

- Toe off is obviously going to be compromised. The patient cannot adequately stabilize the 1st metatarsal (MET) and this will mean a compromised foot tripod, medial foot/tripod splay, arch pronation control challenges but toe off stabilization is going to have to be met by the 2nd and 3rd digits, as discussed above. They are not suited to be the major players here, they are synergistic to this end. Do not be surprised to see one of 2 strategies at toe off here:

1. heavy medial foot tripod toe off, dropping into the void and this maximize the internal spin challenges and minimizing the requisite foot supination stiffness generation phase that should be normal at toe off

2. avoidance of the above, with a forced conscious forefoot lateral toe off, a supinatory strategy, to avoid internal limb spin, more toe hammering, and the lurch heavily and abruptly off of the right foot and onto the left limb.

Screen Shot 2018-08-10 at 8.10.27 AM.png

3. taking #2 further, any time there is perceived challenges or deficits in strength, endurance, proprioception, balance, power and the like, the brain often will create a premature departure off of said limb, creating a requisite premature loading onto the opposite limb. This can cause a phenomenon well loosely refer to "catching" in the contralateral quadriceps mechanism. These clients, with their abrupt loading pattern onto the opposite limb will most often have troubles getting into initial gluteal hip stabilization strategies, and thus default into a quadriceps strategy, that in time can lead to quad shortness and increased tone, which can cause more compression across the patellofemoral joint and cause knee pain. This is more of a compression/loading response issue rather than tracking phenomenon, which we see at the typical diagnosis. We often look for causes in the opposite limb for contralateral knee pain. IT is quite often there if you are looking hard enough for it. Fix the problem, not the symptom.
There is a long host of other things than can arise from here, including heavy contralateral (in this case left sided) foot loading challenges, often more forefoot initial loading, and all of the problems than can arise when this pattern is cyclical, but that would take this post far too deep and long. So, . . . . another time.

Screen Shot 2018-08-10 at 8.09.47 AM.png

4. Shoe fit, we could make the case that a shoe that nicely hugs the forefoot, as opposed to a wide toe box'ed shoe, could help fight off the risk of 1st metatarsal abduction and thus bunion formation risk. However, one cannot dismiss the wider toe box giving the remaining toes a better environment to engage without hammering with over use of long flexors. We might suggest a trial of an elastic sleeve, one often used for plantar fascitis symptom management, placing a snug one around the forefoot when ambulating. This could help keep that metatarsal snug and stop the bunion-like drift we would be watching for.

have at it gang, cases like this are far and deep and require deep understanding of normal and abnormal biomechanics, and the rabbit hole deep myriad of compensations that can be engaged.

have a great weekend !

Shawn and Ivo

You need toe extension, more than you might think.

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There is a major difference in these 2 photos.One foot is ready for foot loading, the other has one foot over the starting line, and is going to possibly have the risks related to inappropriate loading.

In clients with one of several possible issues related to poor control of the arch during weight bearing loading, it is not all too uncommon for us to bring to their attention that not only do they NOT utilize toe extension appropriately, and at the right time, they just simply have poor strength and endurance of the toe extensors (we will not be bringing up the complicated orchestration of the long and short toe extensors today, lets just keep it loosely as looking at them as a whole for today).

We know we say it an awful lot, that clients need more toe extension endurance and strength. But more often than not, they need more awareness of how little they are actually using their toe extensors during foot loading. This is why we despise flip flops and foot wear without a back strap on them, the flexors have to dominate to keep the footwear on the foot.  And, if you are into your toe flexors, you are definitely not into your toe extensors.

Screen Shot 2018-07-20 at 9.23.54 AM.png

You can easily see in this photo that there is a major difference in the integrity and preparation of the foot arch prior to foot loading in these 2 sample photos. One the toes are up in extension, the other the toes are lazy and neutral.  The toe up photo demonstrates well that when the toes are extended, the Windlass mechanism draws the forefoot and rearfoot together and raises the arch. Go ahead, lift your toes, it will happen on you as well (unless your arch is so collapsed that the first metatarsal actually dorsiflexes during toe extension, in this case, you are a whole different management tier). From this arch raised position, the first metatarsal is adequately plantarflexed, this means the joint complexes proximal and distal to the metatarsals are all in the right position to load and cope with loads. In the toe neutral picture, these components are not prepared, the arch is already getting ready to weight bear load from a half-baked position. One cannot expect the foot complex to load well when it is starting from a position of "half way there". One should start the loading of the foot from the starting line, not 3 steps over the line and not 3 steps before the starting line.  There is no athletic or mechanical endeavor that does well when we start the challenge too soon or too late, timing is everything.

How you choose to prep your foot for contact loading, and yes, there is some conscious choice  here, one is lazy the other is optimal, can determine to a large degree if you or your client is about to fall into the long list of problems related to poorly controlled pronation (too much, too soon, too often, too fast). Any of those bracketed problems lead to improper loading and strains during time under tension.

We will almost always start our clients on our progressing protocol of arch awareness and we will loosely say arch restoration, and attempts at better optimizing the anatomy they have, with toe up awareness.  Many clients will have poor awareness of this component issue, on top of poor endurance and frank weakness. The arch is to a great degree build from a lifting mechanical windlass effect, from the extensors and foot dorslflexors, not from the foot flexors. This is one of our primary beefs with the short foot exercise of Janda, there needs to be a toe extensor component in that exercise (search our blog for why the short foot exercise is dead). The short foot exercise is not actually dead, all exercises have some value when placed and performed properly, but the short foot exercise is based off of the toes being down and utilizing the plantar intrinsics to push the arch up and shorten the foot, this is a retrograde motion and it is not how we load the foot, but, it does have value if you understand this and place it into your clients repertoire appropriately.  This is also why we have some conceptual problems in stuffing an orthotic under someones arch to "lift it up", ie. slow its fall/pronation.  There are times for this, but why not rebuild the proper pathways, patterns and mechanics ?

Teach your clients about toe extension awareness. TEach them that they need to relearn the skill that when the toes drop down to the ground that the arch does NOT have to follow them down, that the client can relearn, "toe up, arch up . . . . . then toes down, but keep the arch up".  IT is a mantra in our office, "don't let your arch play follow the leader".  Reteach the proper neurologic disassociation between the toes and arch.

Perhaps the first place you should be starting your clients with foot and ankle issues, is regaining awareness of proper toe extension from the moment of toe off, maintaining it through swing, and then keeping it until the forefoot has purchase on the ground again, and not any time sooner than that ! If their toes are coming down prior to foot contact, it is quite likely their arch is following the leader.

So, if your client comes in with any of the following, to name just a few:  tibialis posterior tendonitis, plantar fascitis, heel pain, forefoot pain, painful bunions, arch pain, hallux limitus, turf toe, . . . . and the list goes on. Perhaps this will help you get your client to the starting line.

Shawn & Ivo, thegaitguys.com

 

Do you really understand what it takes to control the 1st Metatarsal during loading ?

Do you have dorsal (top) foot pain, at the peak of the arch? Think you are tying your shoes too tightly and that is the cause? Do you have pain over the dorsal or plantar mid foot on heel rise or jumping/landing or going up stairs ?

Just because you raise your heel and load the ball of the foot does not necessarily mean you have adequately plantarflexed the 1st metatarsal and loaded it soundly/stable with the medial tarsal bone. Heel rise, and thus loading onto the medial foot tripod, must be met with ample, stable, durable, 1st metatarsal plantarflexion and the associated medial tarsal bones. Also, without this, loading of the sesamoids properly cannot occur, and pain may ensue.

The first ray complex can be delicate in people who are symptomatic. In some people who do not have a good tibialis posterior-peroneus sling mechanism working harmoniously, in conjunction with a competent arch tripod complex to achieve a compentent arch complex (ie, EDL, EHL, tib anterior and some of the other foot intrinsics) this tarsometatarsal interval can become painful and instead of the 1st ray complex being stable and plantarflexing as the heel departs and the 1st ray begins taking load, it may not do so in a stable plantarflexed posturing. In some people it can momentarily dorsiflex as the arch subtly collapses (when it should be stable and supinated in heel rise).

"Subtle hypermobility of the first tarsometatarsal joint can occur concomitantly with other pathologies and may be difficult to diagnose. Peroneus Longus muscle might influence stability of this joint. Collapse of the medial longitudinal arch is common in flatfoot deformity and the muscle might also play a role in correcting Meary's angle."-Duallert et al

Soon, I hope to show you a video of how to watch for this problem, how to train it properly, how we do it in my office.
Dr. Allen

Reference:

Clin Biomech (Bristol, Avon). 2016 May;34:7-11. doi: 10.1016/j.clinbiomech.2016.03.001. Epub 2016 Mar 10.  The influence of the Peroneus Longus muscle on the foot under axial loading: A CT evaluated dynamic cadaveric model study. Dullaert K1, Hagen J2, Klos K3, Gueorguiev B4, Lenz M5, Richards RG6, Simons P7.

https://www.ncbi.nlm.nih.gov/pubmed/27015031

Trying again here. VIDEO CASE: Is this lateral compartment weakness ?

Quite simply, there are too many people playing doctor out there that do not have the ability to examine their clients appropriately. Here is another case of just that.
It is clear that this client has left lateral compartment deficits. Or is it too much medial compartment tone ? Your screens and loading tests will not likely show you this specifically, this client may merely present, as they did in this case of left frontal plane hip-pelvis drift and a right cross over step. If you have been with us for awhile, you know these 2 match up when it comes to locomotion. But one must solve the "Why" for the "how" to be accurate (how to fix it).
But, if you are looking for weakness, you will find it here, yes, peronei and lateral gastroc are weak. But is it inhibition or neurologic or frank weakness ? It is because of heightened medial compartment tone ? It could be, thus making one think of possible centrally mediated processes.
And, is the ankle the source or the frontal plane drift (glute weakness) the source ? Cart or the horse ? Chicken or the egg ? You have to examine your clients, on and off their feet, shoes off, socks off (yes, i took the socks off afterwards). Screens are not enough if you are trying to solve problems. Fixing how your client's improper loading is not a fix always, it could merely be teaching a compensation over a compensation to a problem. Be smarter than the rest, get the knowledge to examine your clients deeper , and more specific, function. Then, how they are moving, and the movements that you see that you do not like, will make more sense.
in this case, if you do not address the foot and the hip abductors and pelvis stabilizers, you lose, and so does your client as you build more strength into their asymmetry . . . . eventually leading, possibly, to complaints.

Video case: Ankle dorsiflexion ? Um, maybe, maybe not.

The more i talk to people about ankle rocker and ankle dorsiflexion, the more i realize they just do not have all the anatomical understanding behind it. But how does one apply the concepts if they don't fully understand it ? It is baffling.
The client should be assessed both passively and actively. When you look at someone's ankles during their gait, do you look at the knee response at ankle dorsiflexion  or at heel rise or during forefoot loading? Do they momentarily hyperextend the knee? Flex the knee? Rotate the foot or leg internally or externally ? To they prematurely heel rise ? Do they prematurely unload the limb and lurch to the other limb thus shortening step length? Do they progress strongly to the lateral forefoot during loading or do they find a middle ground and begin the pronation phase timely with a proper progression to the medial foot tripod ?  Remember, what you see is their strategy, not their problem, do not correct what you see, correct the cause of what you see.

In this video, look at the excessive right knee flexion that occurs here during active ankle dorsiflexion. One must understand what this could mean, and then should be able to see some of the causation during gait. One of the calf complex muscles crosses the knee, one does not. One of them is short on this right side in this client with acute achillies tendonitis. It is not necessarily the cause, but it a piece of the puzzle. Both the clinician and the client do not realize that there is often a knee flexion response during active and passive ankle dorsiflexion assessment, especially when there is mechanical pathology. Having a foam roller under the knee can really bring it out, as in this case. But, remember, this should not be the standard of your assessment, because you are putting slack into the posterior mechanism.