Hey Check it out! John Wayne has either a Left short leg or a weak left Gluteus medius and a compensatory increased arm swing on the Right ! Watch for the lean to the left on Left stance phase and the arm swing to pull him through. WE guess even the Duke needs a hand sometimes !
The “Dukes” of Gait Shawn and Ivo
If you are not assessing for impaired hip muscle function in your knee patients, you could be missing the boat …….. and it is a big boat…… Titanic in size.
Don’t be like so many others and be tunnel visioned when you have a knee patient, expand your vision, at least to the hip and foot.
We are……. The Gait Guys……. Shawn and Ivo
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Am J Sports Med. 2009 Mar;37(3):579-87. Epub 2008 Dec 19.
Physiology Laboratory, PPEH Unit, University of Saint-Etiene, France.
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What The Gait Guys have to say about this article:
How long do you run in the shoes at the store before you decide whether they are a good match or feel for you ? This study suggests that if you take less than 4 minutes in a pair, you are not getting the accurate feel of the shoes. Your “running stiffness” takes at least 4 minutes to adapt and alter to a given shoes materials. Each shoe will likely feel different. Don’t be fooled by the EVA’s softness, or the sock liner’s plushness. They might be there to offset what this study found, that being…… shoe stiffness increased significantly during the first 4 minutes but beyond the 4th minute, shoe properties remained stable.
How many stores or shoe companies are telling you this one !?
Well, we are telling you right here and right now…….. first impressions are not always the best ones.
* Read the study’s conclusion below…… and think (and feel) before you buy. Read your favorite internet blogger’s shoe reviews with an educated eye, and an open mind. What they feel and report could very likely be the exact opposite of what you feel because their anatomy and running style could be very different from your own.
We are, without a doubt…… from all angles…….. The Gait Guys
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When mechanical parameters of running are measured, runners have to be accustomed to testing conditions. Nevertheless, habituated runners could still show slight evolutions of their patterns at the beginning of each new running bout. This study investigated runners’ stiffness adjustments during shoe and barefoot running and stiffness evolutions of shoes. Twenty-two runners performed two 4-minute bouts at 3.61 m.s-1 shod and barefoot after a 4-min warm-up period. Vertical and leg stiffness decreased during the shoe condition but remained stable in the barefoot condition, p < 0.001. Moreover, an impactor test showed that shoe stiffness increased significantly during the first 4 minutes, p < 0.001. Beyond the 4th minute, shoe properties remained stable. Even if runners were accustomed to the testing condition, as running pattern remained stable during barefoot running, they adjusted their leg and vertical stiffness during shoe running. Moreover, as measurements were taken after a 4-min warm-up period, it could be assumed that shoe properties were stable. Then the stiffness adjustment observed during shoe running might be due to further habituations of the runners to the shod condition. To conclude, it makes sense to run at least 4 minutes before taking measurements in order to avoid runners’ stiffness alteration due to shoe property modifications. However, runners could still adapt to the shoe.
Article link: http://www.ncbi.nlm.nih.gov/pubmed/16498177 , get this article for yourself.
The Saucony Progrid Mirage
Well it has been about a year now and we have seen enough of our Track athletes, Mid distance, Cross Country, Marathon and IronMan athletes (by the way, congrats to our Tom K for a fantastic 8 place IN THE WORLD finish at the China Ironman this month. Guys like you make docs like us look really good !)……back to the post….. we have had enough athletes over the year in many different shoes. Months ago we were speaking somewhat favorably of the Saucony Kinvara, another 4mm rise minimalist shoe. Our only beef with it was that the black outsole burns out real fast and it shortens the life of the shoe. They really need to extend the black harder rubber outsole to the edges of the EVA foam on the sole. Turn a pair over, you will see what we mean.
So, we are now favoring another shoe in this category by this company. We have seen enough to feel that it is a nice alternative, and one you will barely notice the difference. But you should get a bit more life out of the shoe and it does have a small medial arch built into the midsole EVA which should help with some medial collapse if foot strike is not pristine from time to time.
Remember, minimalist shoes are not for everyone. You must have, or earn, a competent foot structure to earn the right to wear them. Walking, not such a big deal, for that we are a fan of this shoe. But for running, if you pronate beyond what is safe, this is not the animal for you.
happy shoe hunting…….. Shawn and Ivo
the gait guys
shoes make the man…
Many of our readers may not know, Dr Ivo is a bass player. Straight from the world of bass are some totally outragous shoes froma totally outrageous bass player. For those of you who don’t know him. Meet….Bootsy Collins….
WARNING: These shoes are not Gait Guys Approved : )
Congrats to our good friend and colleague, Dr Mark Cucuzella, just won ANOTHER Air Force marathon. Congrats to you, Mark . Read all about it here:
Circumducting gait.
This is a great video. This is a video we found on the internet. There is another one showing her with a much more pathologic steppage gait, we may bring this one to your attention another time. She may have had a cerebral event or mild stroke from what the other video showed. But we like this one, because it is subtle and much more likely what you are going to see day to day in your world.
We see here on the video a left sided circumducting gait. What this means is that the left limb is not swinging purely through the sagittal plane from heel lift-toe off phase to repeat heel strike again. Instead we see the foot sweep laterally. The foot moves immediately into an increased progression angle (turned out), and it sweeps around a half circular motion to repeat the contact phase again at heel strike.
In this case here it is clearly evident, especially on the lateral side view, that she is blocked out of left ankle rocker (dorsiflexion) for some reason. She does not even get to 90 degrees dorsiflexion range at the ankle mortise. She can no longer allow the treadmill to draw her left foot backwards because she hits this limitation. As the limitation is met, the foot must come forward now (because it cannot go anywhere else, certainly not backwards). But, she does not display enough right gluteus medius use to create hiking of the left hip to create the clearance necessary for this premature forward left leg swing. Thus, she has to spill the left leg out to the side in a circular-circumducting fashion to clear the limb from hitting the ground. She is also likely doing it because if you are not able to dorsiflex the ankle, you will be relatively plantarflexed at the ankle. And if you are plantarflexed, you are much more likely to catch your toe on the treadmill-ground during the swing through phase. This case is a problem of not creating sufficient clearance for the left foot.
Also take note of the subtle foot drop on the left. The foot cannot maintain adequate dorsiflexion, due to weakness of the anterior compartment (possibly from a cerebral event?). Did you see the lack of inversion of the left foot as well. This is usually accomplished by the tibialis anterior and long extensors, especially EHL, neither of which is seen (take a look at the amount of hallux extension on the R on the lateral view and compare it with the left). How about that subtle midfoot collapse as well?
There are other reasons for a circumducting gait. This is just one. Some are functional limitations, some are ablative orthopedic type limitations such as post surgical, some are neurological, and some are a combination. Taking a good history, knowing your gait parameters and assimilating the information will bring you to an answer.
Then you have to figure out what to do. In this case, we do not know, because we do not know what parameter is causing the compensation you see here. This is a good case of “what you see is not what is wrong, you are just seeing what they are doing while working around limitations and finding parts to use and cheat with” to still be able to more forward.
We are The Gait Guys, —- Ivo and Shawn
This week Dr Ivo talks about interneurons and interneuronal pools. Sounds a little unexciting till you learn the importance of these little buggers!
Enjoy!
Why Runners need to take a page out of their automobile maintenance manual when it comes to running injury prevention.
Tissues have limits. They are like a tire, they only have so much tread on them before they show pathology. But like a tire, it takes time for a wear pattern to show up enough to make the tire wobble or the axle to pull the car mildly towards the ditch. Take a spinal disc, it has a certain number of compression and load cycles before it begins to desiccate, especially in the higher load / transition zones of the spine. Cartilage has a certain number of cycles before it begins to desiccate and crack/fissure and flake. Osteoarthritis then begins its slow sneaky onset. Tendons and ligaments have the same “limited lifespan” especially if loaded imperfectly with strained joint loads. Just because someone is pain free doesn’t mean they are safe. The abnormal load on an ITB band doesn’t begin the moment that pain presents itself. The problem brews in the background long before there is pain. Pain and injury represent a failure point in the mechanism. At this point it is too late. Being in medicine, we would be just like all the others if we crisis managed every athlete that walks in the door. So, we are in the game of prevention. We know our biomechanics, we know our orthopedics, physiology and neurology as good as the best out there. And so , we are well positioned on the front lines to identify problems before they ensue, and pick up on that aberrant wear pattern on the proverbial “tire” long before the pattern of wear is so bad that an injury is immanent and a foregone conclusion. So, this bodes the bigger question, just because you are injury free for many marathons and decades, doesn’t mean you shouldn’t take your car in , have its tires rotated, lug nuts snugged up, and alignment tweaked so that your car’s life will be maximized. Remember, unlike a car, we get one set of tires. We cannot replace bolts, we cannot remove the rust or put in a new oil or air filter. All we can do it make sure our “car” , our body, is working as best it can with the anatomical parts it has.
We do not think anyone would disagree that leaving alone and ignoring a 99% stenosed artery in the heart’s “widow maker” artery is a good idea just because someone hasn’t had a heart attack yet. Checking the body for malfunction early can prevent some unpleasant problems down the road. Pain or tightness is the dashboard’s “check engine” light. Regular check ups should keep that light off and reduce the sudden anxiety that comes when it turns on.
In summary, we take our cars in for tune up maintenance 2-3 times a year. And usually we drive away without the car driving too much different. But, we are at ease knowing it is in tip top shape and can go another 6000 miles before it might show signs of wear. We should do the same with our body and our gait mechanics and fix and change the little things that are sneaking up on us that could trigger that “check engine” light. By the time it comes on, it could be too late and require major repairs which just might keep your “car” off the road for awhile while repairs are made. No one likes to hear from the mechanic, “well Mr. Jones…….if we had checked up on this earlier before it was a big problem, we could have prevented this expensive set back on the sidelines.”
Our bottom line, even if your running is pain and injury free for years on end (which would make you a rare bird as runners go), it should make sense to you that improving biomechanical deficiencies isn’t likely a bad thing for the long term. Rather, it is probably the smartest of choices to keep you on your journey down the road, around the next bend, one efficient step after another.
“An ounce of prevention is worth a pound of cure”. -Ben Franklin
In this PART 2 installment of Applied Hip Gait Biomechanics, Dr. Allen delves deeper into a complex topic and attempts to bring it to a level that everyone can understand and implement. Here he talks about the hip mechanics in relation to pelvic stability and gait.
It is our goal to share as much of our collective 37 years of clinical experience as we can in a medium that is usable, friendly and understandable to all viewers.
Thanks for taking time out of your busy lives to care about watching our videos.
Shawn & Ivo, ……. The Gait Guys
The New Brooks Pure Project line. 4 models in the line.
To set your understanding level for the entire video…… at the start he says the first shoe has a 14-10 offset. That means 10mm of foam under the forefoot, and 14 under the heel, almost a 1:1 heel rise:forefoot rise meaning that the heel is only raised 4 mm compared to the forefoot. This leaves a ramp angle probably well below 5 degrees, depending on your foot length. As he discusses the other 3 shoes, he will mention different offsets…… like 15-11 for the Pure Grit. Notice the net change is still 4mm offset. So they all have the same 4 mm heel rise. The 14-10 Pure Connect as the least amount of EVA foam under the foot, so you supposedly will “feel” the ground more. With less foam, you need to be a better shock absorber with your body. The Pure Flow is 18-14 offset, meaning more EVA foam for more cushion and shock absorption. Remember…. transitioning to minimalistic shoe wear like this means that your heel will be suddenly ~10 lower than it is used to in shoes. Your “trainers” , your older style shoes, have raised the heel and allowed for a slight shortening of the calf and achilles complex, let alone monkey’d around with the normal biomechanics that should have been occurring. So, suddenly dropping 10mm may take some time. Play it safe, start with every other short run, wean into them.
We have been waiting for this shoe line. We hope it holds up to our standards, and prior Brooks Standards.
The Gait Guys
And now… A question from a reader….
Dr Allen- There are a few questions troubling me. The first one concerns the loss of the ankle rocker phase of gait which can have implications further up the kinetic chain. It concerns the interplay of gastroc and soleus. Is it possible for gastrocnemius to work as a knee extensor when the foot is in the closed chain position - especially if the bodies centre of mass has advanced in front of the knee joint ? Thanks - RB
Hi RB_____,
yes it is possible…….it is a retrograde movement as you have described.
it is not commonly seen, but can be, and usually manifests itself, in one of 2 ways.
Typically the client is more ligamentously lax than others……..and they tend to have a “kicking” type gait, where they thrust the leg out in front, like kicking a ball, with each step forward. This causes a heavy heel strike and locks the knee in preparation for midstance, and then follows your thinking. By the way, this client also seems to like standing in a hyperextended knee position at rest.
We remember that the gastroc soleus group begins to fire in the first 10% of stance phase (it is acting as a knee extensor here); to promote eccentric deceleration of the forward moving tibia, and continues to fire until terminal swing. It is believed the soleus provides much of the deceleration force and the gastroc assists in inverting the ankle at midstance and primarily flexes the knee at pre swing, just prior to toe off (Nordin, Frankel 2001). If the gastroc /soleus group fires prematurely, or excessively, particularly in prior to midstance, then we see the action you describe, and it manifests itself as premature heel rise and loss of ankle rocker.
A sudden hyperextesion at midstance or later, in a neurologically competent individual, is unlikely, as he force is too abrupt at this point and there is too much of a mechanical disadvantage.
We hope this helps explain things a bit. Please email us back if it doesn’t!
Uber Geeks, Shawn and Ivo
J Sci Med Sport. 2011 Jul 29. [Epub ahead of print]
Terry PC, Karageorghis CI, Saha AM, D'Auria S.
Department of Psychology, University of Southern Queensland, Australia; Centre of Excellence for Applied Sport Science Research, Queensland Academy of Sport, Australia.
Music can provide ergogenic, psychological and psychophysical benefits during physical activity, especially when movements are performed synchronously with music. The present study developed the train of research on synchronous music and extended it to elite athletes using a repeated-measures laboratory experiment. Elite triathletes (n=11) ran in time to self-selected motivational music, a neutral equivalent and a no-music control during submaximal and exhaustive treadmill running. Measured variables were time-to-exhaustion, mood responses, feeling states, RPE, blood lactate concentration, oxygen consumption and running economy. Time-to-exhaustion was 18.1% and 19.7% longer, respectively, when running in time to motivational and neutral music, compared to no music. Mood responses and feeling states were more positive with motivational music compared to either neutral music or no music. RPE was the lowest for neutral music and highest for the no-music control. Blood lactate concentrations were lowest for motivational music. Oxygen consumption was lower with music by 1.0-2.7%. Both music conditions were associated with better running economy than the no-music control. Although neutral music did not produce the same level of psychological benefits as motivational music, it proved equally beneficial in terms of time-to-exhaustion and oxygen consumption. In functional terms, the motivational qualities of music may be less important than the prominence of its beat and the degree to which participants are able to synchronise their movements to its tempo. Music provided ergogenic, psychological and physiological benefits in a laboratory study and its judicious use during triathlon training should be considered.
Well, they say shoes make the man…or in this case, get your condiments….not..
Happy Friday
Ivo and Shawn
Dr. Shawn Allen discusses Gait Biomechanics again, this time pure hip biomechanics and how it applies to gait and running and compensation patterns. This is Part 1 of 2 of the Hip Biomechanics. This is essentially applied biomechanics.
Today, in Neuromechanics weekly, Dr Waerlop talks about the differences between alpha and gamma motor neurons and their influence on muscle tone.
Well, in some ways, Barefoot IS better!
In those famous words: Res ipsa loquitur (The thing speaks for itself)…Well sort of…
Though some research is conflicting regarding barefoot running as being better, or more injury preventative, chalk one up for the efficiency of barefoot.
Glossary:
vVO is percentage of maximal velocity of graded exercise test. in this case 70%.
VO(2) is the maximal amount of O2 the body utilizes for an exercise
RPE: is how hard you perceive you are working for a given exercise or task
video provided courtesy of Two Rivers Treads and Newton Running
Int J Sports Med. 2011 Jun;32(6):401-6. Epub 2011 Apr 6. Oxygen cost of running barefoot vs. running Shod. Hanson NJ, Berg K, Deka P, Meendering JR, Ryan C. Source
Health, Physical Education and Recreation, University of Nebraska at Omaha, United States. njhanson@gmail.com
Abstract
The purpose of this study was to investigate the oxygen cost of running barefoot vs. running shod on the treadmill as well as overground. 10 healthy recreational runners, 5 male and 5 female, whose mean age was 23.8±3.39 volunteered to participate in the study. Subjects participated in 4 experimental conditions: 1) barefoot on treadmill, 2) shod on treadmill, 3) barefoot overground, and 4) shod overground. For each condition, subjects ran for 6 min at 70% vVO (2)max pace while VO (2), heart rate (HR), and rating of perceived exertion (RPE) were assessed. A 2 × 2 (shoe condition x surface) repeated measures ANOVA revealed that running with shoes showed significantly higher VO (2) values on both the treadmill and the overground track (p<0.05). HR and RPE were significantly higher in the shod condition as well (p<0.02 and p<0.01, respectively). For the overground and treadmill conditions, recorded VO (2) while running shod was 5.7% and 2.0% higher than running barefoot. It was concluded that at 70% of vVO (2)max pace, barefoot running is more economical than running shod, both overground and on a treadmill.
Pretty cool, eh?
Ivo and Shawn, 2 geeks making a difference
Forefoot stiffness. It’s all in the supination…
Remember a month ago when we talked about the basics of gait? If not, please see posts the week of 6/27 for a in depth discussion
Suffice it to say, in stance phase (about 60% of the walking and 40% of the running gait cycles) we have 2 motions occurring: pronation and supination. In pronation (which begins as soon as the foot hits the ground and should end at midstance) the foot is becoming a mobile adaptor, so it can adapt to irregular surfaces and act as a shock absorber.
In supination (which begins at midstance and ends at preswing) the foot is becoming a rigid lever, to assist in transferring muscular forces to the lower limb to propel us forward.
The picture above shows supination nicely. Remember that when one foot is in midstance, the opposite leg (in swing phase) assists in supination.
This study (IOHO) demonstrates the principle of supination nicely and demonstrates the (major) role the foot plays in forefoot stiffness.
J Biomech. 2005 Sep;38(9):1886-94. A comparison of forefoot stiffness in running and running shoe bending stiffness. Oleson M, Adler D, Goldsmith P. Source http://www.ncbi.nlm.nih.gov/pubmed/16023477
Department of Mechanical and Manufacturing Engineering, University of Calgary, 2500 University Drive, N.W. Calgary, Alberta, Canada T2N 1N4.
Abstract
This study characterizes the stiffness of the human forefoot during running. The forefoot stiffness, defined as the ratio of ground reaction moment to angular deflection of the metatarsophalangeal joint, is measured for subjects running barefoot. The joint deflection is obtained from video data, while the ground reaction moment is obtained from force plate and video data. The experiments show that during push-off, the forefoot stiffness rises sharply and then decreases steadily, showing that the forefoot behaves not as a simple spring, but rather as an active mechanism that exhibits a highly time-dependent stiffness. The forefoot stiffness is compared with the bending stiffness of running shoes. For each of four shoes tested, the shoe stiffness is relatively constant and generally much lower than the mean human forefoot stiffness. Since forefoot stiffness and shoe bending stiffness act in parallel (i.e., are additive), the total forefoot stiffness of the shod foot is dominated by that of the human foot.
The Geeks of Gait: Ivo and Shawn
Born to Run?
Perhaps we really were born to run. This study looks at the forefoot, the phalanges and their potential role in the evolution of our feet.
We know impact forces increase with running, so it makes sense that physical and metabolic demand to continue forward momentum would increase as well. Longer lever arms (such as longer toes) would require greater torque on the muscles as well as increased lift of the foot (to provide ground clearance), and most likely a different orientation of the rearfoot and trochlea that the flexor tendons would have to pass through. This would probably result in a more cavus, rigid foot as well.
The study did not state, but suggested muscular recruitment of the flexors is distinctly different in walking vs running, and that there is less “balance” between the flexors and extensors. We contend that with appropriate gait patterns (ie, using the glutes as a primary hip extensor), long flexor activity would be more balanced with long extensor activity and this disparity would not be seen.
The video has nothing to do with the study, we just thought it was pretty funny
Sorting out the details so you don’t have to; The Gait Guys
J Exp Biol. 2009 Mar;212(Pt 5):713-21. Walking, running and the evolution of short toes in humans. Rolian C, Lieberman DE, Hamill J, Scott JW, Werbel W. Source http://www.ncbi.nlm.nih.gov/pubmed/19218523
Department of Anthropology, Harvard University, Cambridge, MA 02138, USA. cprolian@ucalgary.ca
Abstract
The phalangeal portion of the forefoot is extremely short relative to body mass in humans. This derived pedal proportion is thought to have evolved in the context of committed bipedalism, but the benefits of shorter toes for walking and/or running have not been tested previously. Here, we propose a biomechanical model of toe function in bipedal locomotion that suggests that shorter pedal phalanges improve locomotor performance by decreasing digital flexor force production and mechanical work, which might ultimately reduce the metabolic cost of flexor force production during bipedal locomotion. We tested this model using kinematic, force and plantar pressure data collected from a human sample representing normal variation in toe length (N=25). The effect of toe length on peak digital flexor forces, impulses and work outputs was evaluated during barefoot walking and running using partial correlations and multiple regression analysis, controlling for the effects of body mass, whole-foot and phalangeal contact times and toe-out angle. Our results suggest that there is no significant increase in digital flexor output associated with longer toes in walking. In running, however, multiple regression analyses based on the sample suggest that increasing average relative toe length by as little as 20% doubles peak digital flexor impulses and mechanical work, probably also increasing the metabolic cost of generating these forces. The increased mechanical cost associated with long toes in running suggests that modern human forefoot proportions might have been selected for in the context of the evolution of endurance running.
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