Yup. We thought we had seen it all. Make sure to wear your evening formal neoprene. Coming soon: Underwater Gait Analysis.
Have a great Friday
Ivo and Shawn
photo credit: xcitefun.net
Foot Landing Mechanics→
/Foot Landing Mechanics, Part 1 of 2
This dialogue is likely going to open up a storm of controversy and dialogue, … good !
In a very recent article in LER (Lower Extremity Review) Katie Bell wrote a nice article about foot “Orthotics and Landing Mechanics”. Her article, and the research she referenced, suggests foot orthoses can affect frontal and transverse plane motion in proximal joints during landing from a jump. It was postulated from the research that orthotics could therefore help reduce the risk of anterior cruciate ligament injury, particularly in females.
In the May issue of the Journal of Applied Biomechanics, it was determined that gender differences as well as foot orthotics affect frontal plane hip motion during landing after a vertical jump. This is really nothing new or mindblowing. Heck, putting a pebble in someone’s shoe will change their landing and gait mechanics, but it is nice to see more talk in the research. Any observant and educated clinician can see that from a vertical jump, if the client does not have enough gluteal function to slow the internal spin of the limb (the glute is a powerful external rotator and thus also a powerful eccentric controller of internal rotation) that the knee will valgus medially. Furthermore, if the foot is not strong and stable, the downward weight will collapse (to varying degrees) the arch and thus also drag the knee medial. Thus, it is critical to discuss both components of knee stability, meniscal issues and ACL issues. Any study omitting observations of gluteal function and only commenting on the effect and merits of the orthotic to control the knee is only telling half the story. Admittedly, research articles can look at isolated issues like this study did if it pleases them, but it is our mission not to let tunnel visioned biases enter into things. Tunnel vision leads to assumptions that some problems have simple solutions. Our clients get evaluated through the entire kinetic chain when looking at foot and knee issues. Heck, even arm swing and opposite leg swing impact the function of the stance phase knee (look at the mechanics behind the Abductory Twist for example or read our blog posts from early December on arm swing impacting lower limb mechanics).
We are not dismissing these research findings however, yes orthotics can help reduce risk at the ACL … IN SOME CLIENTS, but it could enable risk in others if the correction at the foot is not the proper intervention. What if the entire risk scenario is from a dysfunctional hip ? Now you have changed the foot’s dynamic compensation for the hip dysfunction. Couldn’t that increase ACL risk ? You bet it can. Thankfully, as we read on, the LER article quoted Walter Jenkins PT, DHS, associate professor and chair of ECU’s Department of Physical Therapy. “Dysfunctional hip motion is commonly observed in patients with knee pathology.” It was nice to see that, sadly we felt the articles angle was to mediate the dysfunctional hip motion via correction at the bottom. We all should be reminded that the organism must be evaluated and thus treated as a whole.
Modifying dysfunctional hip motion locally, if there are local issues, can reduce knee risk and may modify the necessity or degree of intervention at the foot level. So, landing mechanics are about the foot, the hip and the knee mechanics pending the mechanical forces from those other two joints above and below. Merely adding an orthotic is going to change the landing mechanics but, as we mentioned earlier, putting a pebble in someone’s shoe is going to change their foot dynamics and how they load, so is a pebble a reasonable answer too ? The question is are they the mechanics you want for your client ? Are the foot changes with an orthotic locally prostituting the normal hip mechanics ? Orthotics are not the Holy Grail. In some cases they are the Devil’s pitchfork. It takes a very educated and skilled practitioner to know the difference.
The Journal of Applied Biomechanics researchers analyzed the 3D motion of the lower extremities in 36 study participants (18 women, 18 men) during a vertical jump with and without prefabricated foot orthoses. In the women researchers found significantly less hip adduction with foot orthoses compared with no orthoses (p< .05). The men showed no differences between foot orthoses conditions. So, does this mean that the women need orthotics ? Or does it mean that their Q angle is a participant ? Does the study necessarily mean that the answer to these ladies issues is an orthotic ? Or does it mean that they could need more hip stability and loading skills to dampen internal limb rotation and valgus knee drift ? The article (thankfully) does suggest that the apparent gender-specific proximal reactions to foot orthoses during landing may be related to kinematic landing strategies which is a good observation, but do not think that orthoses are the take away answer from this article.
The study also showed things we have talked about previously, that being that men actually land in knee varus and use hip adduction and knee valgus as a strategy to accelerate during the jump after the deceleration phase of landing. Where as women tend to land more valgus and but seem to be more challenged to control this force. But for an article to suggest that “A foot orthotic may be a simple solution—and quicker than neuromuscular retraining—to control motion.” is a scary conclusion. They go on to say “Ultimately, orthoses may be an excellent adjunct to a neuromuscular training program.” we agree with in part.
Nothing is more valuable than a limb that can support and control itself with optimal neuromuscular function. If you do not have it, take time away from risky sport challenges until you have achieved it. Do not take a short cut and depend on an external device, unless of course the client has a fixed anatomical compensation or issues (ie. forefoot varus) OR you are using it as a training aid, to TEMPORARILY offer mechanics that the client does not have, working toward helping them to eventually get them. In those cases, a device is often helpful and recommended, but IT IS IMPERATIVE to retrain neuromuscular protective reflexes and function.
We are going to do a Part 2 on this very important topic this weekend. If you are in a sport where you are jumping and landing you absolutely need to read Part 2. We will be offering up a hopeful epiphany for you on why so many people sprain their ankles. It is a landing mechanics problem…… not discussed anywhere else in the research or on the web….. until now !
We are The Gait Guys …. two guys who always finding themselves standing outside some strange box everybody is talking about.
Have a good Friday everyone !
Shawn and Ivo
A 30 second workout has similar results as a 90 minute one ?→
/McMaster University (Canada) studies on the effectiveness of high intensity interval workouts.
Sprint Results Set the Stage
The 2005 study and others (links provided above), published in the Journal of Applied Physiology and , showed that three to seven all-out sprints on a stationary bicycle (250% of VO2 max), 30-seconds each, with four-minute rest periods, six times over two weeks, are as effective as 90 to 120 minutes of cycling at moderate intensity (65% of VO2 max) six times over two weeks. Both workouts improved endurance capacity by almost 100%, increasing time to fatigue at 80% effort from 26 minutes to 51 minutes. In short, about 15 minutes of hard sprints spread over two weeks produced the same results as nine to 12 hours of moderate intensity effort.
Both the sprinters and the traditional riders showed a substantial increase in citrate synthase, a mitochondrial enzyme that indicates the power to use oxygen, along with increased glycogen (muscle sugar) content. Neither group, however, showed a change in maximum oxygen uptake (VO2 Max, or the ability to utilize oxygen per kg of body weight in liters per minute; it can be approximated to % max heart rate with the formula %MHR = 0.64 × %VO2max + 37) or anaerobic work capacity (ability to produce lactate, a byproduct of anaerobic metabolism).
The interesting thing about this study, is that the high intensity exercise group should have produced more anaerobic work (ie more lactate) and probably did BUT were able to clear it faster because of the short duration of the exercise. Remember that the 1st few seconds of the 30 second sprint would have been using creatine phosphate stores, before tapping into the glycogen stores.
The lower intensity exercise at 65% VO2 Max works predominantly the aerobic system (incidently, 65% of VO2 Max is probably a “moderate exercise” and is probably less demanding); thus these folks would be better able to recycle lactic acid, should the levels rise to levels requiring it. Changes in VO2Max would be able to be changed much less (3-5%) in trained individuals than untrained (up to 20%), so the findings are not that surprising.
The bottom line is that high intensity training offers some gains that are similar to traditional aerobic training with less time, and should probably be included in your training regimen.
Shawn and Ivo……..Striving to increase your knowledge base more efficiently
Does stretching make a difference? Does it enhance or inhibit performance?
Today’s discussion is not fiction or merely our opinion, you should know by now that The Gait Guys are not about presenting misinformation, we are about presenting the facts. Today’s dialogue is based on hard, solid, peer-reviewed research and neurophysiology principles. If you feel you disagree with us, please present your research papers so we can begin a productive dialogue amongst us.
Join Dr Ivo in this weeks neuromechanics to explore these questions and more. Also check out past episodes of neuromechanics weekly on our Youtube channel: “The Gait Guys”
Have a great day!
A few minutes in our Brains.
/We were over at a book store on the weekend and picked up a book called Incognito written by neuroscientist David Eagleman.
The gist of the book was that the majority of brain activity is largely subconscious. That the brain is continuously processing information and working algorithms to questions and problems that we have inquired about either consciously or subconsciously. A conscious example might be pondering which new computer to buy, factoring in price, model, manufacturer, specs, hard drive size, peripherals desired, etc. Over a period of minutes, hours or days you bounce around the issues until you rationalize a best decision for your needs and wallet. On the other end, a subconscious example might be learning a new motor skill in your gait pattern. For example perhaps, a pathologic pattern is the one being learned. In one case the brain may be subconsciously learning to reduce gluteus medius muscle in an attempt reduce hip joint compression forces and thus hip pain due to a degenerative joint cartilage surface (see Dr. Allen’s recent video, Applied Hip Gait Biomechanics, Sept 15). In this scenario the brain was working out the algorithm to solve for the pain. The brain is continuously subconsciously processing to solve these problems, it is always working in the background, in sleep or in a wakeful state. We have all had these epiphany moments where the solution to a problem comes to you seemingly out of the blue. However, it is not the case. The brain had been at it for some time.
Eagleman describes the conscious brain as a CEO who is handed a final product that has been worked on by hundreds of employees for weeks, those employees being the subconscious brain parts. The CEO is the last to know, they only get to see the end success of hundreds of hours of work by the employees, and they often take full credit because they are the CEO afterall. It is a long process to achieve solutions to complicated problems. Afterall, do you really think Steve Jobs made the iPad all by himself ? Some might.
Where are we going with this ?
Unconscious incompetence: you do not know the right foot has turned out during gait.
Conscious Incompetence : someone has brought it to your attention.
Conscious Competence: you find a reasonable motor pattern to turn the foot in, but you must stay conscious of this pattern for the correction to be maintained.
Unconscious Competence: eventually unknowingly achieving the foot alignment correction. Give the brain the correct information … then give it time and the correct supportive exercise and let the brain figure it out. It will bring that foot inline eventually as long as there are not other impeding factors. The key is making sure that the pattern you teach your client , or that you institute yourself, is not a compensation. That’s the hard part ! You have to know what is right before you know what is wrong. Pick the wrong pattern and you find yourself down a fork in the road that is full of potholes and problems. Don’t guess. See someone who KNOWS. We had a guy fly in to see us yesterday and this was exactly the case. Therapy has been prescribed in-part off of a video gait analysis and incorrect physical evaluation. You can’t guess at this stuff. You gotta study!
Coming directly from our temporal lobes, we are…The Gait Guys
The Gait Guys. Two weeks ago you talked about a dog’s gait, now cockroaches ? Yup, watching nature at work fosters much insight into gait principles.
Biomimetics, also known as Bionics, is another name for engineering systems that copy principles found in nature.
If you are real gait geeks you have probably seen some of the cool robots inspired after the insect world. Many of these robots are called hexapods (six legged robots), just like insects. With 6 legs alternating limbs on opposite sides of their exoskeleton (see diagram above) it can provide an inherently stable tripod mechanism that is effective and efficient in when it comes to locomotion. Insects are great models because they have an extremely stable and efficient model of locomotion through something called a tripod gait. We have a video link demonstrating this a little further down. At any time, cockroaches for example have 3 limbs in contact with a surface. This tripod structure makes them very stable and mobile.
The stability of the hexapod comes from its ability to establish this gait pattern in which at least three legs are on the ground at any time. Just like the 3 legs of a tripod, when they are firmly planted, the platform is very stable. You will notice from our year of blogging that we continue to talk about the foot tripod, consisting of stability points at the head of the 1st and 5th metatarsals and the heel. These 3 points of stability of the foot are necessary to make up the longitudinal and transverse arches of the foot. Without the ability to anchor these 3 points effectively on the ground the foot becomes unstable and compromised. Hence why we see bunions, hallux valgus, metatarsalgia, abnormal plantar callus patterns as well as various presentations of foot pain in feet that have lost the tripod ability. The key however is then to place, and maintain, the body mass within the confines or borders of the triangle made by joining these 3 tripod points (see the colored area in the diagram above). In humans, if your body mass deviates towards the outside of the tripod, in other words approaching or violating an imaginary line drawn from your 5th metatarsal to the heel (ie. approaching supination), you tip the foot laterally and begin to compromise the anchoring of the medial foot tripod (under the 1st metatarsal) and risk formation of bunions and hallux valgus among other functional pathologies of excessive or constant supination. On the other hand, If your body mass approaches or exceeds the arbitrary medial border of the triangle delineated by a line drawn from the head of the metatarsal to the heel you are considered a possible hyperpronator and all of the functional pathologies that accompany it (ie. plantar fasciitis etc). Bottom line … a tripod is stable, just stay withing the colored lines. Note in this cool video (click here) how clear the 3 pronged tripod engages and how the body mass of the robot stays within the borders of the tripod limbs. In other words, keep your ankle and more specifically the force vector, over your foot tripod (the colored lines), and most pathology issues will be absent. The closer you get to tipping the tripod, the closer you are getting to developing biomechanical pathology in the lower limb. Put another way, by increasing weaknesses in the foot intrinsic and extrinsic muscles and possibly the other stabilizers of the lower limb and pelvis, the closer your body mass will fall towards the edges/limits of the tripod triangle borders. And the closer you are to the risk of gait pathology and pain.
( In the diagram above, for you hexapod insect loving gait fans, the most basic hexapod walking pattern is called the alternating tripod gait. Taken from this site, in this gait, the six legs are treated in two groups of three. Either group of three is a tripod formed by the front and rear legs of one side, and the middle leg of the opposite side. The three component legs of each tripod are moved as a unit. As one tripod is lifted, the other tripod pushes forward. In this gait it can be helpful to think of each tripod as a foot and compare it to your own bipedal walking where as one foot is lifted the other foot pushes forward.)
And you still thought we were just your average Gait Guys, didn’t you ?! If it walks, trots, gallops, canters, jumps, runs, jogs or whatever….. we are on top of it. Yes, even if that means cockroaches ! We are here to stay gang, in 2012 we will begin to execute our plan for intergalactic dominance, gait related only of course.
Nerd Shawn & Geek Ivo
A Coach with Anterior knee pain: About as common a problem as finding dirt on a child.
We get emails like this all the time. Here is one from a coach with a problem.
Hi Gait Guys,
I was just found your blog visiting one of the running sites I like coachjayjohnson.com. I’m a high school xc/track coach and a former runner myself. I say former because I dug a nice hole in my cartilage in the lateral trochlear groove about 4 years ago from running. This actually happened 3 months after I stopped wearing the custom orthotics i had been wearing for about 8 years. What a mistake that was, but the biggest mistake might have been getting them in the first place.
Anyways, 3 months ago I had a procedure done to regrow the cartilage. this was done at the stone clinic in San Francisco. The doctor said I should wait a year before I attempt to run again. I’m fine with that but sometime next year once my knee is feeling good enough I’d like to come see you guys before I start running again so that you can help analyze everything and get me out there running again with good form and in the correct shoes etc. Where are you guys located? Also, are you going to come out with some new DVDs?
Thanks,
(name removed)
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What The Gait Guys have to say …
Dear Coach:
(Links in our discussion have been embedded for you and other readers and we have included a picture above so everyone else will know where your problem was.)
Anterior knee pain in runners is about as common a problem as finding dirt on a child. You have described the all to common, osteochondral defect. IT is a defect of bone and cartilage quite often from blunt or repetitive trauma.
Knee joint anterior malalignment is multivariably associated with patellofemoral osteoarthritis (study). Alignment issues at the knee can be driven by variations of the optimal anatomy (versions and torsions, see a post on this from ~3 weeks ago) but in our opinion they are often driven from other factors most notably improper biomechanics driven by muscle weaknesses-tighness. However, other factors can come into play to complicate the scenario, such as poorly selected footwear for a foot type. Alignment at the knee is subservient to the mechanics at the hip and foot. Both the hip and foot are multiaxial joints, whereas the knee in its healthy state and most basic description, a sagittal hinge joint (sure, miniscule rotation). When the hip or foot are prostituted and some of the availability of their normal motion is lost or changed (as is possibly the case of an orthotic as you eluded to, however in the hands of a skilled practictioner the orthotic can help positively restore compromised function, if they understand and assess whole limb kinetic function) the knee joint can often find itself in the middle of altered biomechanical force streams. This all to often can lead to anterior knee pain, compromised function of the patellofemoral joint. This, as in your suspected case, can lead to abnormal cartilage wear at the interface of the two bones.
In one article it was proposed that physical activity may modify the association between joint incongruity and cartilage loss, and can be further affected by subject characteristics such as gender. It must be part of the thought process that rather than it being the activity, is more likely to suspect altered biomechanics during said activity as being the culprit. Understanding these complex interactions will help optimize strategies to maintain patellofemoral joint health. However, this study found that for every one-degree increase in the proximal trochlear groove angle at baseline, there was an associated 1.12 mm increase in the annual rate of patella cartilage volume loss. This brings a person’s given anatomy, perhaps suboptimal anatomy, into play and thus adds one’s risk factors. There was a trend for this effect to occur for males, as well as people participating in vigorous physical activity. Males who exercised vigorously were more adversely affected.
In conclusion, this study showed that in vivo engineered cartilage was remodeled when implanted; however, its extent to maturity varied with cultivation period. The results showed that the more matured the engineered cartilage was, the better repaired the osteochondral defect was, highlighting the importance of the in vitro cultivation period.
There are many surgical interventions out there for anterior knee pain, such as tuberosity transfers, retinacular releases, injections, and God forbid patellectomies among others (yes, we have clients who decades ago had this done, imagine that! Thankfully this radical move is no longer done !). Most people simply need a well versed biomechanist who understands the whole kinetic chain, understands the force streams, can assess for the limitations and reduce them to restore the previous normal mechanics. Sadly, sometimes interventions are not optimal or precise and folks end up like you coach. And then surgery is your only option. Thanks for sharing your story and reaching out to us. Sharing your anonymous story may help others avoid your painful journey. We would be happy to see you, we are getting more and more letters like yours both here in the home land and internationally. Hopefully, our mission will help reduce these problems, if at least just a little. (PS: yes, our 3 part Shoe Fit / Biomechanics & Functional Anatomy DVD and online program should launch in February. Information about the launch will be right about the time phase 2 of the website will lauch www.thegaitguys.com).
Best to you.
Shawn and Ivo, The Gait Guys
Genu valgum in kids: What you need to know
We have all seen this. The kid with the awful “knock knees”. It is a Latin word “which means “bent” or “knock kneed”. It appears to have 1st been used in 1884.
This condition, where the Q angle angle exceeds 15 degrees, usually presents maximally at age 3 and should resolve by age 9. It is usually physiologic in development due to obliquity of the femur, when the medial condyle is lower than the lateral. Normal development and weight bearing lead to an overgrowth of the medial condyle of the femur. This, combined with varying development of the medial and lateral epiphysies of the tibial plateau leads to the valgus development. Gradually, with increased weight bearing, the lateral femoral condyle (and thus the tibial epiphysis) bear more weight and this appears to slow, and eventually reverse the valgum.
Normal knee angulation usually progresses from 10-15 degrees varus at birth to a maximal valgus angle of 10-15 degrees at 3-3.5 years (see picture). The valgus usually decreases to an adult angle of 5-7 degrees. Remember that in women, the Q angle should be less than 22 degrees with the knee in extension and in men, less than 18 degrees. It is measured by measuring the angle between the line drawn from the ASIS to the center of the patella and one from the center of the patella through the tibial tuberosty, while the leg is extended.
Further evaluation of a child is probably indicated if:
- The angle is greater than 2 standard devaitions for their age (see chart)
- If their height is > 25th percentile
- If it is increasing in severity
- If it is developing asymmetrically
Management is by serial measurement of the intermalleolar distance (the distance between ankles when the child’s knee are placed together) to document gradual spontaneous resolution (hopefully). If physiologic genu valgum persists beyond 7-8 years of age, an orthopaedic referral would be indicated but certainly intervention with attempts at corrective exercises and gait therapy should be employed. Persistence in the adult can cause a myriad of gait, foot, patello femoral and hip disorders, and that is the topic on another post.
Promotion of good foot biomechanics through the use of minimally supportive shoes, encouraging walking on sand (time to take that trip to the beach!), walking on uneven surfaces (like rocks, dirt and gravel), gentle massage (to promote muscle facilitation for those muscles which test weak (origin/insertion work) and circulation), gait therapeutic exercises and acupuncture when indicated, can all be helpful.
Ivo and Shawn… The Gait Guys…Promoting foot and gait literacy for everyone.
Gait ischemia? Blood flow affecting performance.→
/Research evidence that gait is altered in ischemia (inadequate blood supply) environments.
Know someone with diabetes, peripheral artery disease or spinal stenosis (especially the vascular variety) ?
This study’s findings indicate increased “noise” and irregularity of gait variability patterns post-ischemia. In young healthy individuals who do not have neuromuscular impairments, significant gait alterations are present during walking after a period of interruption of blood flow. This could be from something as simple as muscular compression, or something more serious.
We just wanted to wet your appetite for some stuff like this coming your way, from us, The Gait Guys. If this does not make you think about compressive socks and stockings, you need a second cup of coffee this morning !
Shawn and Ivo
Gait variability patterns are altered in healthy young individuals during the acute reperfusion phase of ischemia-reperfusion.
Source
Nebraska Biomechanics Core Facility, University of Nebraska at Omaha, Omaha, Nebraska 68198-3280, USA.
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Gait: Does Minimizing center of mass vertical movement change your metabolic cost ?→
/Research article: Minimizing center of mass vertical movement increases metabolic cost in walking.
Ortega JD, Farley CT. Locomotion Laboratory, Dept. of Integrative Physiology, University of Colorado, Boulder, CO 80309-0354, USA. ortegajd@colorado.edu
J Appl Physiol. 2005 Dec;99(6):2099-107. Epub 2005 Jul 28.
So what is this article’s bottom line ? The premise of the research article was to look at the relationship between vertical movement in gait and its metabolic cost by having human subjects walk normally and with minimal center of mass vertical movement (“flat-trajectory walking”). What the article found was that it costs more to move with a flat trajectory. In other words, dampening the normal vertical oscillations is not a good thing. But we have some concerns.
Not that we have a major problem with this study, but we do have two concerns we think should have been brought up problem.
1- Were these folks in the study assessed for biomechanical compensations ? You have read our discussions on impaired ankle rocker. And one of the major flaws of impaired ankle rocker is the premature heel rise gait, where the person can adopt a rather boucey vertical gait, almost appearing to walk on the ball of their foot. These folks have a very vertical gait.
2- Since the study concluded that the less vertical trajectory gait was seen to be far less metabolically efficient it is a well founded question to ask more about the strategy they employed. In the study they merely added more joint flexion to dampen the vertical trajectory. But, had they been coached to use the core to minimize vertical trajectory and utilize the energy moving forward while still obtaining some of the normal biomechanical components, some of which take advantage of limb extension, would the study have found the same thing ? Once again we find a good study but one that bodes more questions than it answers, such as, did the researchers really know enough about gait biomechanics to give good cues? Furthermore, how much vertical is too much ? How much dampening is too much ?
We still appreciate the study and its findings, but you cannot trust everything you read, at least not without reading the fine print. Here is the full abstract below. Read it yourself and if you are curious enough, get the full study for yourself.
Shawn and Ivo…….keeping you on the edge of the research.
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Journal Abstract
A human walker vaults up and over each stance limb like an inverted pendulum. This similarity suggests that the vertical motion of a walker’s center of mass reduces metabolic cost by providing a mechanism for pendulum-like mechanical energy exchange. Alternatively, some researchers have hypothesized that minimizing vertical movements of the center of mass during walking minimizes the metabolic cost, and this view remains prevalent in clinical gait analysis. We examined the relationship between vertical movement and metabolic cost by having human subjects walk normally and with minimal center of mass vertical movement (“flat-trajectory walking”). In flat-trajectory walking, subjects reduced center of mass vertical displacement by an average of 69% (P = 0.0001) but consumed approximately twice as much metabolic energy over a range of speeds (0.7-1.8 m/s) (P = 0.0001). In flat-trajectory walking, passive pendulum-like mechanical energy exchange provided only a small portion of the energy required to accelerate the center of mass because gravitational potential energy fluctuated minimally. Thus, despite the smaller vertical movements in flat-trajectory walking, the net external mechanical work needed to move the center of mass was similar in both types of walking (P = 0.73). Subjects walked with more flexed stance limbs in flat-trajectory walking (P < 0.001), and the resultant increase in stance limb force generation likely helped cause the doubling in metabolic cost compared with normal walking. Regardless of the cause, these findings clearly demonstrate that human walkers consume substantially more metabolic energy when they minimize vertical motion.
On and on goes the barefoot debate.
There is no single right answer, so use your head.
We have been saying what this article talks about all along, even years before the Vibram 5’s hit the market, back when Vibram came to us to ask us for our thoughts on the early versions. You will see our soapbox rant on this topic over and over again in our blog posts and it is the modus operandi behind our new 2012 Shoe Fit program that will likely launch February 1st in several forms for several professions to meet everyone’s needs.
That modus operandi being that not everyone has a foot type, anatomy or biomechanics to get into minimalist shoes, without a possible cost that is.
In this nicely written article by Cynthia Billhartz Gregorian “Barefoot running: Sales grow, but so does debate about benefits, safety” at the link above she lightly covers some of the aspects of the debate. We have read just about every piece that has come out on the barefoot-minimalist trend. Sadly, some of the blogs are mere opinion and it is rare that the honest truth comes out. That truth being our mention above that some folks just do not have the skill, endurance, strength or anatomy to delve into footwear that does not support or protect their physical limitations. Lets be honest, at 5'9’’ I have to come to the realization that no matter how much i practice to be in the NBA I am not going to make it. I just do not have the physical anatomy to be an NBA star. And some people, no matter how much they want to run barefoot or minimalist, just do not have the anatomy to allow it. Someone with a history of foot pain who has a rigid forefoot varus really is not going to do well in minimalist shoes. There are articles written out there that just tell people to bite the bullet and go 100% into their new minimalist shoes, into the natural way they were supposed to run from the very start and force the body to adapt, that the new form they adopt will take care of any problems. Well, in our experienced and educated opinion, that is just not smart. Someone who has a shortened posterior compartment (calf-achilles) after being in heel shoes for years is going to have several flaws biomechanically going to minimalist shoes right off the bat. One example, just one for now, is that the person is going to have premature heel rise and thus premature forefoot loading response around a compromised ankle rocker mechanism. And there are many others of course.
Here is the bottom line as we see it. No shoe company is going to run a commercial or add on their product with the warnings on the cover or in the fine print. We are not talking about cigarettes here. Admitting that some people should not be in their product would be admitting that the product has limitations and risks. What kind of advertising add would that be ? Besides, admitting to limitations or mentioning warnings is a mere step away from liability cases. We are pretty sure of this, after all, look what happened to the Shape Up Shoe in the courts.
Here is what we say to the naysayers, look at the research and use logic. If you are new to the game, leave the extremist blog sites for those that are looking for radical opinions. Because we do not have any openings in our clinics for the next several weeks if you throw caution to the wind.
Good running to you all in 2012, use your head, for the sake of your feet.
Shawn and Ivo
Ataxic gait?
We hope you have begun the new year in a NON ATAXIC manner. Lets look at the origin of the word:
Ataxia: Greek, from a or without + tassein to put in order or “without order”. Ataxia is truly gait without order, and we will see why momentarily. The term was coined in 1670. Every September 25th is International Ataxia Awareness Day. Mark THAT ONE on your calendars!
Ataxia an inability to coordinate voluntary muscular movements that is symptomatic of some nervous system disorders and injuries and not due to muscle weakness.
It is a lack of afferent information either GETTING TO the CNS, BEING PROCESSED BY the CNS, or OUTPUT FROM the CNS. We can still hear Dr Carrick saying “where is the longitudinal level of the lesion? Is it at the receptor, the effector, the peripheral nerve, the spinal cord, the brain stem, the thalamus, the cerebellum or cerebrum?” This mantra, still rings true many years later, as it gives us the afferent pathway to the brain and higher centers of the CNS.
Ataxic gait, not to be considered synonymous with Fredreich’s Ataxia (the genetic disorder described in the 1860’s, related to spinal cord and cerebellar degeneration), can be due to any number of causes which affect processing of afferent information. One too many Tequila’s (100% agave of course), barbituates, joint pathomechanics, diseases affecting receptors (like syphilis or leprosy), diabetes and other forms of peripheral neuropathy, spinal cord injury or disease are only a few of the causes. Virtually anything that can affect the afferent processing or efferent arc of the processing of proprioceptive information.
The large amplitude corrective movements are clues to the CNS that something is awry and are a necessary component of the compensation. Here , you truly are seeing the result of the compensation.
The video offers a simplified explanation and nice clinical example of an ataxic gait. If you don’t believe it, try some field research (or perhaps you already have) with the ethanol of your choice and see for yourself. Of course, some of THAT ataxia comes from changes in specific gravity of the endolymph in your inner year, but that is the subject of another post.
Ivo and Shawn. The Gait Guys…New and Improved for 2012
Proof that the contralateral limbs are programmed. Wait, are you guys showing dog gait video today ? yup, and for good reason.
This is how good our eyes are trained at gait stuff. How good are yours ? Can you pick out what we saw immediately when watching this clip ? It is something really cool, perhaps proof that contralateral limbs, upper and lower, are programmed and automatic. Even in dogs apparently. Did you see it ? You may have to have to watch the video several times.
The dog initially is striking with the left forelimb while pairing that with right hindlimb just after (remember, this is running gait, not walking) . Kind of like how in human gait the left arm swing is in sync with the right leg swing (both in either flexion or extension, at the same time). We believe the central pattern generator for gait occurs in an area of the spinal cord at the junction of the the thoracic and lumbar spines (just like in the large sauropod dinosaurs!) click here for more info
But what is really cool is that there is a sudden change at 0:23sec. The dog changes midstride to strike first with the right forelimb and immediately alters the hind limb to strike first with the left. Can you see it ? Look again. Isn’t the nervous system amazing!
Just as in humans the pattern change seems to be immediate and subconscious. The rhythm and sync is predictable. It appears that even in animals the arm swing topics of weeks ago on in-phase and anti-phase of the shoulder and pelvic girdles hold true.
Did you see it immediately ? It may take you time to train your eyes like ours, but if you watch enough videos perhaps you too will have gait observation superpowers.
Limb swing, even in animals, offer information to learn from and extrapolate to humans. Bipeds, quadrupeds….we don’t discriminate.
Shawn and Ivo……..gait experts……. on many levels.
Not another Cross over runner ! Yup, and some new pearls on the topic.
Watch this video (and we will post her second video shot from the side in a separate blog post) so you can see some of the components we will talk about today.
Quite often in the Cross over gait the runner has great difficulty getting into the glutes (max and medius) effectively.
In this video today from Runblogger, we see yet another runner who is lacking skill and strength in the appropriate muscles and patterns to run efficiently.
- In this video it is clear that she has the classic Cross-Over stride flaw. This video is nice because there is a line present to support our cause, the feet at basically falling on a line instead of below the hips. We see the typical far lateral foot strike in this runner that is classic for Crossing over. This more lateral strike, even though it is a nice midfoot strike (see the side video shot in the other video of her we post), causes pronation to occur quicker and longer than normal and can create an abductory twist when the heel departs from the ground. However, we do not see the abductory twist like we saw in the Lauren Fleshman videos. Why not ? because this runner has the foot progression angle at zero, perhaps negative 5 degrees (what we are saying is that she is toe’d-in). This is appears to be from her having mild internal tibial torsion. And a negative foot progression angle will help hold the arch through pronation and in this case is protecting from the abductory twist of the foot at heel rise. There is most likely a forefoot varus here as well (note the inversion at strike). Most likely it is functional; she appears to have inadequate motion in the rear and midfoot, so the pronation must occur somewhere and we see it here in the forefoot.
Pretty cool to see how a subtle change in one’s anatomy can play out differently. Go back and watch the Fleshman video blog of weeks ago and watch for the abductory twist of the feet.
2. In this runner, what we really wanted to discuss however is the poor motor control of the gluteus medius and maximus (maximus will be in #3). We can clearly see in this video that during all phases of stance, the pelvis is dipping on the contralateral side. This downward drop is creating a greater gluteus medius lever arm and thus greater demand on the gluteus medius, and in this case a failed attempt (if the opposite hip were hiked, the lever arm would be reduced and put lesser demand on the gluteus medius, less fatigue factor). New to this concept ? Click here.Think now about the reciprocal pairing with the adductors and you could understand why her adductors are probably shortened as well; the adductor magnus especially, as it has a secondary motion of external rotation, and it is probably being substituted here to help decelerate the internal spin of the lower extremity
As the longer lever pairs with the body weight factor, there is a vertical descent of the body and this must be made up by eccentric control of the gluteus maximus (the option of optimal choice) or it is dumped into the quadriceps and they are expected to cope with the body mass descent by slowing knee flexion. She appears to be opting for the later, not a good choice.
3. Now switch over to the frontal plane (side) shot of this runner in the other blog post. Can you clearly see that the quadriceps are being asked to control the decent? Look at the vertical oscillations of her body. Look at the amount of knee flexion occuring at impact. It is clear that the gluteus maximus is not dampening this drop and this can be seen by the amount of hip flexion noted here. We always think of the glutes as extensors but in gait they are huge dampeners of the rate and degree of hip flexion.
This is very inefficient running. She could be much more effective and faster if she works on these issues. If she can just pair improved gluteus medius to control the frontal plane pelvis drop, and improve the maximus to control the sagittal drop there would be more energy to move forward and less wasted into overcoming the ground reaction forces (which she is maximizing) as dictated by Newton’s Laws.
are we the only ones seeing this stuff ? hopefully you are starting to get real good at this stuff.
The Gait Guys, saving one runners life (and hips and knees) one day at a time.
Shawn and Ivo
The Gait Guys on Movement, Physiologic Overflow & Muscle Function.
Movement is largely isotonic, meaning that muscles maintain a steady state of contraction (“same tone”) throughout a physiological range of motion; in other words, our body mass does not change as we move through space. Exercise is specific as to the type of contraction (isometric, isotonic, isokinetic) and speed on contraction. Different rehabilitative exercises we prescribe can have different results based on the points or angles of application. This video discusses some of these points. See us also on You Tube: The Gait Guys
Watch for a Podcast of classic Shawn and Ivo at noon!
SCARY gait of the week.
OK, so we do not even have one complete gait cycle to look at, but what an excellent clinical example.
Here is an example of someone who has not earned the right to forefoot strike. Go ahead, step through the video a few frames at a time.
First notice the abductory twist of the Left foot as it leaves the ground (toe off). You will also notice that the left foot also leaves the ground with a low gear toe off instead of a strong push off the big toe/medial foot. Now watch the external rotation and abduction of that extremity (:05) so it can plan for the next footstrike and try and clear the Right leg. Why is this ? Well, we do not have a complete gait cycle but if you were to draw a line down the middle of the treadmill you would see that this is a great example of some of the things that occur during the CROSSOVER GAIT. Yup, we are back pounding this flawed gait technique. It is common to strike the ground on the far lateral foot and then pronate quickly through the midfoot. It is also common to increase the foot progression angle.
One might suspected forefoot varus as seen from :03-0:05, with the sudden forefoot pronation of the Right foot. It does look mostly controlled however, the steep Right forefoot varus positioning the the air before contact could bode more for the mechanics that go with the CROSSOVER gait. (CrossOver gait you say ? Haven’t seen our 3 Part Cross Over gait video series on YouTube ? click here for Part 1)
DO NOT TRY THIS AT HOME!!! Ditch the prison socks, read our treadmill article coming out soon in Triathlete magazine so you know the true problems of treadmills, and learn to run with good technique.
Have a marvy day, you footgeek, you
Ivo and Shawn
