Check out our take on this classic that we “remade” for The Natural Running Center (www.naturalrunningcenter.com) and Zero-drop.com.
Thanks for the opportunity, guys!
The Gait Guys
Gender differences in walking and running on level and inclined surfaces.
Chumanov ES, Wall-Scheffler C, Heiderscheit BC. Clin Biomech (Bristol, Avon). 2008 Dec;23(10):1260-8. Epub 2008 Sep 6.
What the Gait Guys have to say about this article:
This article highlights some of the differences in gait between males and females on treadmills. Though treadmills don’t necessarily represent real life, they are an approximation. While reading this article, please keep the following in mind:
1. the treadmill pulls the hip into extension and places a pull on the anterior hip musculature, especially the hip flexors including the rectus femoris, iliopsoas and iliacus. This causes a slow stretch of the muscle, activating the muscle spindles (Ia afferents) and causing a mm contraction (ie the stretch reflex). This acts to inhibit the posterior compartment of hip extensors (especially the glute max) through reciprocal inhibition, making it difficult to fire them.
2. Because the deck is moving, the knee is brought into extension, with stretch of the hamstrings, the quads become reciprocally inhibited (same mechanism above).
3. The moving deck also has a tendency to put the ankle in dorsiflexion, initiating a stretch reflex in the tricep surae (gastroc/soleus) facilitating toe off through here and pushing you through the gait cycle, rather than pulling you through (with your hip extensors).
4. the moving deck forces you to flex the thigh forward for the next footstrike (ie footstance), firing the RF, IP and Iliacus, and reciprocally inhibit the g max
If your core isn’t engaged, the pull of the rectus femoris and iliopsoas/iliacus pulls the ilia and pelvis into extension (ie increases the lordosis) and you reciprocally inhibit the erectors and increase reliance on the multifidus and rotatores, which have short lever arms and are supposed to be more proprioceptive in function. Can you say back pain?
In summary, treadmills are not the scourge of humanity, but do have some pitfalls for training, and equal amounts of “backwards” running should be employed (with great caution, mind you)
With that being said, lets look at the results: increased hip internal rotation and adduction, as well as more glute activity for the ladies. Not surprising considering women generally have a larger Q angle (17 +/- 3 degrees for females, 14 +/-3 degrees for males) and greater amounts of hip anteversion (average 14 degrees in females vs 8 in males). The larger Q angle places more stress at the medial knee (compression of the medial femoral condyle and usually increased pronation as the center of gravity over the foot is moved medially) and thus more control needed to slow pronation (from the glutes to control/augment internal rotation). Greater hip anteversion means the angle of the femoral head is greater than 12 degrees to the shaft of the femur. This moves the lower extremity into a more internally rotated position, approximating the origin and insertion of the adductors, making them easier to access. With an increased Q angle and easier access, greater demands are placed on adductors in single leg stance (which is considerably greater in running), This increased adductory moment places more demand on the gluteus medius (and contralateral QL) as well, to stabilize the pelvis and this correlates with speed and incline, also found in the study.
The take home message? Don’t throw away your treadmill! The treadmill can be an excellent diagnostic tool! Gluteal and adductor insufficiencies will be more visible (and probably more prevalent) in females, especially those running or walking on treadmills. The hip extension and ankle dorsiflexion moment created by a treadmill works against some of the stabilizing mechanisms (glute inhibition, ankle dorsiflexor inhibition) and help to highlight some of the subtle gait abnormailities you may miss otherwise.
we remain….The Gait Guys
Lombard’s Paradox
/In searching our personal archives for neat stuff we came across an oldie but a goodie. One to certainly make your head spin. We do not even know where this came from and how much was our original material and how much was someone else’s. If you can find the reference we would love to give it credit. We do now that we added some stuff to this but we don’t even know what parts were ours ! Regardless, there is a brain twister here worth juggling in your heads. Lets start with this thought……..
When you are sitting the rectus femoris (a quad muscle) is “theoretically” shortened because the hip is in flexion. It crosses the bent knee in the front at it blends with the patellar tendon, thus it is “theoretically” lengthened at the knee. When we stand up, the hip extends and the knee extends, making the R. Femoris “theoretically” lengthen at the hip and shorten at the knee. This, it bodes the question…….did the R. Femoris even change length at all ? And the hamstrings kind of go through the same phenomenon. It is part of the uniqueness of “two joint” muscles. Now, onto Lombard’s paradox with more in depth thought on this topic.
Warren Plimpton Lombard (1855-1939) sought to explain why the quadriceps and hamstring muscles contracted simultaneously during the sit-to-stand motion. He noted that the rectus femoris and the hamstrings are antagonistic, and this coactivation is known as Lombard’s paradox.
The paradox is classically explained by noting the relative moment arms of the hamstrings and rectus femoris at either the hip or the knee, and their effects on the magnitude of the moments produced by either muscle group at each of the two joints.
By virtue of the fact that muscles cannot develop different amounts of force in their different parts, the paradox develops. The hamstrings cannot selectively extend the hip without imparting an equal force at the knee. Thus, the only way for hip extension and knee extension to occur simultaneously in the act of standing (or eccentrically in the act of sitting) is for the net moment to be an extensor moment at both the hip and knee joints. Lombard suggested three necessary conditions for such paradoxical co-contraction:
- the lever arm of the muscle must be greater at its extensor end
- a two-joint muscle must exist with opposite function
- the muscle must have sufficient leverage so as to use the passive tendon properties of the other muscle
In 1989, Felix Zajac & co-workers pointed out that the role of muscles, particularly two-joint muscles, was much more complex than has traditionally been assumed. For example, in certain situations, the gastrocnemius could act as a knee extensor. It is clear now that the direction in which a joint is accelerated depends on the dynamic state of all body segments, making it difficult to predict the effect of an individual muscle contraction without extensive and accurate biomechanical models (Zajac et al, 2003).
In fact, back to the gastrocnemius another 2+ joint muscle (crosses knee, mortise and subtalar joints), we all typically think of it as a “push off” muscle. It causes the heel to rise and accelerates push off in gait and running. But, when the foot is fixed on the ground the insertion is more stable and thus the contraction, because the origin is above the posterior joint line, can pull the femoral condyles into a posterior shear vector. It thus, like the hamstrings, needs to be adequately trained in a ACL or post-operative ACL, deficient knee to help reduce the anterior shear of normal joint loading. It is vital to note, that when ankle rocker is less than 90 degrees (less than 90 degrees of ankle dorsiflexion is available), knee hyperextension is a viable strategy to progress forward in the sagittal plane. But in this scenarios, the posterior shear capabilites of the gastrocnemius are brought to the front of the line as a frequent strategy. And not a good one for the menisci we should mention.
Andrews J G (1982) On the relationship between resultant joint torques and muscular activity Med Sci Sports Exerc 14: 361-367.
Andrews J G (1985) A general method for determining the functional role of a muscle J Biomech Eng 107: 348-353.
Bobbert MF, van Soest AJ (2000) Two-joint muscles offer the solution - but what was the problem? Motor Control 4: 48-52 & 97-116.
Gregor, R.J., Cavanagh, P.R., & LaFortune, M. (1985). Knee flexor moments during propulsion in cycling–a creative solution to Lombard’s Paradox. Journal of Biomechanics, 18, 307-16 .
Ingen-Schenau GJv (1989) From rotation to translation: constraints on multi-joint movement and the unique action of bi-articular muscles. Hum. Mov. Sci. 8:301-37.
Lombard, W.P., & Abbott, F.M. (1907). The mechanical effects produced by the contraction of individual muscles of the thigh of the frog. American Journal of Physiology, 20, 1-60.
Mansour J M & Pereira J M (1987) Quantitative functional anatomy of the lower limb with application to human gait J Biomech 20: 51-58.
Park S, Krebs DE, Mann RW (1999) Hip muscle co-contraction: evidence from concurrent in vivo pressure measurement and force estimation. Gait & Posture 10: 211-222.
Rasch, P.J., & Burke, R.K. (1978). Kinesiology and applied anatomy. (6th ed.). Philadelphia: Lea & Febiger.
Visser JJ, Hoogkamer JE, Bobbert MF & Huijing PA (1990) Length and Moment Arm of Human Leg Muscles as a Function of Knee and Hip Angles. Eur. J Appl Physiol 61: 453-460.
Zajac FE & Gordon MF (1989) Determining muscle’s force and action in multi-articular movement Exerc Sport Sci Revs 17: 187-230.
Zajac FE, Neptune RR, Kautz SA (2003) Biomechanics and muscle coordination of human walking - Part II: Lessons from
dynamical simulations and clinical implications, Gait & Posure 17 (1): 1-17.
Follow up post on yesterdays FOOT TRIPOD VIDEO
Good Day Fellow foot geeks !
Yesterday we posted a quick video of a young teenager who came to us for orthotic prescription. As you can see in the early part of the video he had a flat foot posturing and increased foot progression angle (feet pointing too much east and west).
The increased foot progression posturing can be a problem, and accentuate pronation strategies, particularly if it is outside the normative values of 5-15 degrees. This is because during midstance the limb is internally rotating. If the foot progression angle is increased as the limb internal rotation occurs while the body mass is progressing over the foot in midstance, the positioning of the medial tripod of the foot is far off the forward/sagittal progression line (the direction of walk). When the tibia and femur internally rotate on such a foot posturing the degree of pronation is accelerated and accentuated. In another way of explaining it, the subtalar joint is almost falling medially outside of the tripod boundaries and thus cannot be controlled by the tripod. It would be like placing a camera directly on the letter “c” in the triangle diagram above, where the points of the triangle represent the positions of the camera tripod legs. The camera is at risk of tipping over because the mass of the cameral is not within the solid boundaries of the triangle. In the foot, these tripod leg points would be represented by the 1st and 5th Metatarsal heads and the heel forming a triangle. The goal is to stabilize the tripod on level ground and place the camera (foot) in the middle of the tripod for maximal stability. But, when the foot progression angle is increased, the triangle and foot position take on the triangle appearance above, risking pronation excesses.
The problem is that many folks do not know they have developed this problem posturing until symptoms occur. This young lad was brought into our offices by an aware mom who had heard of similar successes we have had with other children and adults.
It took all of 10 minutes to retrain his awareness of the foot tripod and posturing of the feet underneath the body (where he noticed that he could not pronate as much as seen at the end of the video clip). HE did awesome as you can see. For the first time in his life he saw an arch and knew how to correct his foot posturing. He became aware of the use and need for good toe extension to raise the arch (a phenomenon known as The Windlass Mechanism of Hicks). The last stage would be to help him retrain these strategies in gait and various movements.
We will see if we can find that video somewhere.
Bottom line, …….did this kid need an orthotic……. NO ! It would have kept absent the strength development of the muscles needed to make the correction you see in the video. This kid now has a fighting chance to develop normally.
Hope this helps to explain what was going on in yesterdays video.
We are………foot nerds…….
Shawn and Ivo
Dr. Ivo Waerlop→
/Reflection:
Sometimes we take for granted our backup systems. In my case, it is Dr. Waerlop. I have known him for the better part of a decade now and two things come to mind: 1) the guy has never let me down and 2) still to this day there are a rare few people i can think of who are more intelligent than this dude. The man is not only a “friend for the duration” but he is just plain old brilliant, ask anyone who knows him or has heard him lecture. It was a no brainer when he approached me with the idea of The Gait Guys (we had been bouncing our knowledge around the web for awhile when it all came together in that big enormous skull of his.) At that moment i knew we had hit a vein/nerve. From that moment on The Gait Guys were cookin.
I have had other business partners over the decades but i have to say, when you have a backup like this cool cat, business is smooth sailing. I personally wouldn’t hesitate to drive hours for the wisdom and smarts of this guy. Wonder why…..? read this below or check out the link at the top to his website. If you are within a day or two drive of his office, don’t think twice as to whether it will be worth your time. Know a friend within a day’s travel ?,…. don’t hesitate. As we like to say, he has the west coast covered, i have the east and we split the middle !
Thanks for the great partnership dude….i look forward to the next 10 years anticipating the whereabouts of The 2 Gait Guys……..Heck, with just 6 months on Facebook and Social media sites and the tremendous domestic and surprisingly the even bigger international following (collective 30,000 monthly hits !) , i cannot imagine where the next 6 months will leave us, let alone 10 years ! Well, i suppose i can imagine for us……. Perhaps, maybe, just maybe…… someday uploading the day’s blog from our satellite up-link from the bow of our fishin boat (“Big Glutes”) klinking Corona’s and watching the sunset just before pulling up to the pier on St. Barts for a jam session with our new friend-to-be Jimmy Buffet. IF you are gonna dream, dream big !
I wish we could spill the beans on all the stuff in our pipeline for The Gait Guys, but hang tight folks…….there is a bundle to come. We have just gottn’ started !
Check out my brilliant partner below…….and, thanks again for always having my back during the ride man…..
-Shawn
__________________________________________________________
IVO F. WAERLOP D.C., DABCN, CCRP, CCSP, Lic Acp.
Dr Ivo is a 1986 summa cum laude graduate of the New York Chiropractic College. He received his post-graduate neurology diplomate from Logan Chiropractic College; he became board certified in 1990. Dr Ivo works with a broad base of patients including Olympic level, professional and paraprofessional running, skiing and cycling athletes. He is an adjunct faculty member with the Lincoln School of Post-Professional Education. He is engaged in publishing active research on cycling biomechanics and is involved in gait and lower extremity research. He is a board certified Chiropractic Neurologist, Chiropractic Rehabilitation Physician and certified Chiropractic Sports Physician. He lectures nationally on foot-ankle and gait biomechanics in sports and now in advanced acupuncture techniques. He is co-author of the textbook, Pedographs and Gait Analysis: Clinical Applications and Pearls.
Additional Background
Dr Ivo F Waerlop attended SUNY at Albany for his undergraduate work and graduated from the New York Chiropractic College in 1986. He then joined the Core Science faculty at the college and taught anatomy and cadaver dissection as well as Gonstead and Diversified chiropractic techniques. It was at this time he conducted research performing a serial dissection of alar ligaments in cadavers and completed post graduate work in Sports Medicine, receiving his Certified Chiropractic Sports Physician certification.
Dr Ivo then moved to Gloucester, Massachusetts where he founded Gloucester Chiropractic and Rehabilitation, a medically referral based office complete with CYBEX lab. During his time in Massachusetts, he completed additional post graduate work in rehabilitation and was accepted into the chiropractic neurology program at Logan Chiropractic College in St Louis, Missouri. Here, he was one of the fortunate doctors who studied directly under Dr Ted Carrick, and after 3 years and passing his written and oral board examinations, was awarded his Diplomate in Neurology Degree in May of 1991. At this point in time, Dr Waerlop began his post graduate teaching career, 1st in rehabilitation and later in neurology, lecturing throughout the US and Canada.
In late 1996, Dr Ivo relocated to Summit County Colorado, continuing to teach on a post graduate level and began a private practice in Frisco at the CARE Health Group. He began teaching Anatomy and Physiology locally at the Colorado Mountain College, which he continues to do today. In 1999, he relocated to a larger facility in Silverthorne and founded Summit Chiropractic and Rehabilitation, PC, a rehabilitation and neurology referral based practice, with an emphasis on gait and movement analysis.
In 2004, he became interested in acupuncture, largely because his 150 pound German Shepherd (Atlas) was epileptic, and a Veterinary Acupuncturist from Grand Junction (Dr Shalona McFarland) was able to help him control his seizures. Dr Ivo began his studies shortly thereafter and received his acupuncture license in the summer of 2005. He then studied neuromuscular acupuncture under Dr Yun Tao Ma and currently lecture with and is writing an acupuncture book with him.
In August of 2006, Dr John Asthlater joined the practice and the office was moved to our new facility in the Dillon Tech Center, in Dillon. In addition to injury, rehabilitative and preventative care, the new center offers the latest in cutting edge video motion analysis, an orthotic lab, electrodiagnostics, blood glucose and lipid analysis, lactate testing, training programs, expanded hours and many other services.
When Dr Ivo isn’t seeing patients or lecturing, he enjoys spending time tele-skiing, hiking and 4 wheeling with his wife, local photographer Lisa Ortiz, Their son's Vander and Saxxon and their dog, Pons. His hobbies include reading, music and cooking.
Foot Arch Question: Sent in from one of our readers
How would one go about “rebuilding” their transverse arch? The latter is pretty much convex. This also accomapnied by very tight long toe extensors (as evidenced by their tendons being very prominent at the top of my foot and my toes being curled at rest) and have suffered on and off from Morton’s neuroma. The ball of my shoes (right in the middle) is where the insoles of my shoes see the most wear. It’s not a huge concern of mine, but I would like to deal with this. I’ve suffered several ankle injuries (as a basketball player) and although I’ve tried orthotics in the past (for the neuroma), I’ve relied mostly on minimalist footwear (except when playing ball of course…). I know some rehab would be in order and would likely work. I’ve “reconditoned” my big toe abductors in the past and can even cross my second to over my big toe, so am just looking for some direction.
Thanks
Our Response:
As you probably are aware, there are 3 arches in the foot: the medial longitudinal (the one most people refer to as the “arch”, the lateral longitudinal (on the outside of the foot) and transverse (across the met heads).
Your collapsed transverse arch seems like it may be compensated for by a rigid, probably high medial and lateral longitudinal arches. This creates rigidity through the midfoot (and often rear foot) and creates excessive motion to try and occur in the forefoot. Depending on how much motion is available, this may or may not occur.
You don’t seem to be able to get your 1st metatarsal head to the ground to form an adequate tripod, so you are trying, in succession, to get some of the other, more flexible ones there (thus the wear in the “ball” of the foot you noted). This results in increased pressure, metatarsal head pain, possibly a bunion and often neuromas.
From your description, you actually have very weak long toe extensors (and possibly some shortening) which is causing the prominence of the tendons, along with overactivity of the long flexors (and thus the clawing) in an attempt to create stability. I am willing to bet you have tight calves as well (especially medially, from overuse of the gastroc to control the foot) and limited hip extension with tight hip flexors.
The foot tripod exercises are a great place to start, as well as heel walking with the toes extended and walking with the toes up (emphasizing extension, which counteracts the flexors). Stay away from open back shoes and flip flops/sandals; continue to go barefoot and get some foot massages to loosen things up. Maybe use one of those golfballs to massage the bottom of the foot when you get off the course and get some golf shoes that aren’t quite so rigid.
Hey everyone. Have a Great 4th of July!
The Gait Guys
And now for something totally random….
How Much Water should I drink? The basics of hydration
We see many athletes and weekend warriors and are often posed this question; so here you go…
Water is the elixir of life. Too much (hyper hydration) or not enough (dehydration) can both be detrimental to your performance, but how much is enough?
Our bodies consist of about 60-70% water at any point in time. Most men have a higher percentage because they have a higher percentage of muscle mass (unfortunately, adipose tissue contains little water!). We generally lose between 1.5 and 2.5 liters of fluid a day through breathing, urinating and general metabolism. The body must keep a balance of water both inside (intracellular) and outside (extra cellular) your cells. Because the body is in equilibrium, if you sweat, breathe, or urinate too much, you will lose water from your extra cellular compartment. The body will then take water from inside your cells and shift it to outside. Likewise, your brain (hopefully) will stimulate you to drink more and urinate less, helping you to fill up the extra cellular compartment again. The water will then diffuse back into the cells and equilibrium is established again. A lot of this movement of water has to do with electrolytes (charged particles in your blood and body fluids) and their movement across cell membranes. The electrolytes that are most important for us are Sodium (Na+) and Potassium (K+).
When you lose too much water, your blood becomes more viscous (remember, you are losing water, not cells. Less water plus same number of cells equals more viscous liquid). This makes your heart have to work harder to push the blood around. This takes more energy and resultantly your heart rate increases, causing a phenomenon called cardiac drift. An example is when you are exercising for a while at the same intensity and your heart rate increases over time. A loss of 2-3% of your body’s water will decrease your performance by 3-7%! The amount you lose will depend on your exercise intensity and duration as well as temperature. A 20 degree increase in temperature can increase your heart rate as much as 10 beats per minute!!
So, it seems if we drink a lot of water, all will be well. Well, yes… and no. Your body can only absorb about 24-28 ounces of water per hour, any more and it just makes you pee more. You can sweat up to 3 liters (that’s more than 96 ounces!) per hour. Hmm. looks like we will probably be in a deficit. How much we absorb depends on whether we can get the water out of our stomach and into our intestines where it can be absorbed. As you can imagine, there are some things which speed gastric emptying and some which slow it down.
Protein and fat are the 2 main things which slow the trip through the stomach down. If too much of these are in your drink or already in your stomach the water will end up sloshing around and probably leave you not feeling too good. Guess that means lots of protein before or during an endurance workout is probably a bad idea, especially if you are trying to stay hydrated! Small amounts of protein, when combined with carbohydrate can be beneficial, but that’s another subject for another day. So much for all that marketing hype!
Small amounts of carbohydrate (up to 60 grams per hour) can enhance water absorption from the intestines and speed emptying of the stomach. The body can’t process any more than this, and it will actually start to slow stuff down if you do too much.
Sodium (50-70 mg, about a pinch) also helps with water absorption. It has the added bonus of stimulating your hypothalamus to tell you to drink more. If you wait until you are thirsty, it will be too late. You need to drink before you are thirsty!
So, what’s a person to do? Here are some tips:
- Drink small amounts often, especially in hot weather. 6 ounces every 15 minutes is a good pace
- Consider adding some sugar to your water sucrose (table sugar) or maltodextrin are a good start. Remember, no more than 60 grams per hour
- If you don’t like sweet drinks while working out, consider using a gel or goo
- A little salt is a good thing. It improves the taste of the water, helps with its absorption, and stimulates the thirst mechanism.
- Research your workout drink. Ask questions. Many claims are marketing hype and not based on science or physiology.
- Consult with your chiropractor, physical therapist, doctor or trainer with questions
The Gait Guys…telling it like it is
Gait Cycle Basics: Part 5
Swing Phase
Our final chapter in this series….
Swing phase is less variable in its classification. It begins at toe off and ends at heel strike. It comprises 38% of the gait cycle.There must be adequate dorsiflexion of the ankle, and flexion of the knee and hip to allow forward progression.
The following classification is most commonly used:
Early swing: occurring immediately after toe off. There is contraction of the dorsiflexors of the ankle, and flexors of the knee and hip
Midswing: halfway through the swing cycle, when the swing phase leg is passing the midstance phase extremity. Acceleration of the extremity has occurred up to this point.
Late swing: deceleration of the extremity in preparation for heel strike. There is contraction of the extenders of the thigh and knee, as well as dorsiflexors of the ankle.
Perry defines the phases as:
Initial swing: the 1st third of swing phase, when the foot leaves the round until it is opposite the stance foot.
Mid swing: the time from when the swing foot is opposite the stance foot until the swinging limb is anterior to the stance phase tibia
Terminal swing: from the end of midswing, until heel strike
And there you have it. A nice review of the gait cycle. Probably more than you wanted to know, but we want to give you the facts.
Telling it like it is. We are…The Gait guys
Does calf stretching increase ankle dorsiflexion range of motion? A systematic review.→
/Here is a big topic. Everyone seems to think that stretching makes a big difference, truth is it makes a difference, but it is not big. But is “some” enough ?
The topic comes up in a range we really feel is important, ankle dorsiflexion range. You hear us talk about it all the time as “ankle rocker”. The facts are that you need 100+ degrees of ankle dorsiflexion range to achieve normal biomechanics across the ankle ankle in walking, and near 115 degrees for running (put another way, 10degrees past 90degrees vertical for walking and 25degrees past vertical for running, ref. T. Michaud).
If you do not have these ranges then you must compromise normal biomechanics. This is where functional pathology starts, ie. injuries.
This study found the following:
The meta-analyses showed that calf muscle stretching increases ankle dorsiflexion after stretching for
< or = 15 minutes (WMD 2.07 degrees; 95% confidence interval 0.86 to 3.27),
> 15-30 minutes (WMD 3.03 degrees; 95% confidence interval 0.31 to 5.75), and
> 30 minutes (WMD 2.49 degrees; 95% confidence interval 0.16 to 4.82).
So, what does this mean ?
Well, upon initial impressions it seems that none of them gained more than 3 degrees of dorsiflexion range, even after 30 minutes of stretching. The study suggested that these numbers according to research stats, were “statistically significant”.
But in our mind, if you have 90 degrees range, a “statistically significant” loss in our opinion, then gaining another 3 degrees (ok, lets jump the moon and assume you stretched for 60 minutes and achieved 5degrees)…..well, you are still not at 100 degrees and have to compromise normal mechanics which could mean injury.
Bottom line, you have to find another way to get this range back, stretching is not going to float your boat the whole way. This is why we like the shuffle walks (as seen on our YouTube videos) to engage and strengthen the anterior compartment. This strength will help to reflexively release the tight posterior compartment. You cannot have a relatively normal lengthened posterior compartment if the anterior team is insufficiently strong.
The Gait Guys
Just in Time for Friday! We want to thank Bill at zero-drop.com for reminding us about these great shoes. We like the “mukluk like” design with minimal drop from heel to toe, as well as the simplistic, single density sole. Hope these are available for all those kids who don’t like to lace their shoes….
Gait Cycle Basics: Part 4
Pronation as a shock absorber
Heel strike, a traumatic deceleration event with the transfer of weight from one extremity to the other, creates shock which must be attenuated. This is accomplished by 4 distinct mechanisms:
1. ankle plantar flexion at heelstrike, followed by eccentric contraction of the pretibial muscles to decelerate foot fall.
2. subtalar pronation. As the coefficient of friction between the calcaneus and the ground increases, the talus slides anterior on the calcaneus while plantar flexing, adducting and everting. This motion causes concomitant internal rotation of the lower leg. Both these actions cause a time delay, allowing force to be absorbed over a longer period of time.
3. knee flexion. This is a reaction to the heel rocker, forward motion of the tibia, and passive tension in the posterior compartment. It is slowed by eccentric contraction of the quadriceps
4. contralateral pelvic drop, which is decelerated by the ipsilateral hip abductors (primarily gluteus medius). This occurs as weight is suddenly dropped on the contralateral limb
The rockers and shock attenuation are dependent on the integrity of the joints involved, their associated ligaments and cartilage, the functionality of the musculature crossing them and their neuromuscular integrity along with appropriate cortical control of the actions. Being physical medicine practitioners, we understand that the anatomy and physiology cannot be separated and must consider these different components while evaluating the patient.
The Gait Guys….Yup, we ARE foot nerds….Hey, someone has to do it….
Gait Cycle Basics: Part 3
As Promised: The Rockers…
According to Perry, progression of gait over the supporting foot depends on 3 functional rockers
heel rocker: the heel is the fulcrum as the foot rolls into plantar flexion. The pretibial muscles eccentrically contract to decelerate the foot drop and pull the tibia forward
ankle rocker: the ankle is the fulcrum and the tibia rolls forward due to forward momentum. The soleus eccentrically contracts to decelerate the forward progression of the tibia over the talus. Ankle and forefoot rocker can be compromised by imbalances in strength and length of the gastroc/soleus group and anterior compartment muscles.
forefoot rocker: tibial progression continues and the gastroc/soleus groups contract to decelerate the rate of forward limb movement. This, along with forward momentum, passive tension in the posterior compartment muscles, active contraction of the posterior compartment and windlass effect of the plantar fascia results in heel lift.
Now see if you can pick out the rockers in today’s video.
The Gait Guys… We are everywhere!!
Gait Cycle Basics: Part 2
Gait Cycle components
Let’s begin today with a typical walking gait cycle.
There are 2 phases: stance and swing. It comprises approximately 62% of the gait cycle. Inman and Scranton use the following classification:
Heel strike: when the heel hits the ground
Full forefoot load: weight is transferred anteriorly to the forefoot
Heel lift: when the heel begins lifting off the ground
Toe off: the beginning of propulsion
They further divide this into a contact period (heel strike to full forefoot load), a midstance period (from full forefoot load to heel lift) and a propulsive period (from heel lift through toe off)
Jaqueline Perry, the Matriarch of gait, uses a slightly more descriptive classification which we prefer:
Initial contact: when the foot 1st touches the floor
Loading response: weight bearing on the loaded extremity from initial contact and continues until the opposite foot is lifted for swing
Midstance: the 1st ½ of single limb support, beginning when the opposite foot is lifted until weight is over the forefoot
Terminal stance: begins with heel rise and continues until the opposite foot strikes the ground
Pre swing: when initial contact of the opposite extremity begins and toes off ends
She also describes 3 tasks to be performed during a gait cycle: weight acceptance (the limb is able to bear weight), single limb support (when weight is supported by one limb with the other in swing phase), and swing limb advancement (moving the opposite limb through space to become the next stance phase leg.
The question is, how do we adequately progress over the stance phase leg? Stay tuned to our next post for a primer on the 3 rockers….
The Gait Guys…Promoting gait literacy and understanding for the clinician and the consumer.
This week we will focus on the basics of gait and the gait cycle in our attempt to assist in gait literacy
Gait Cycle Basics: Part 1
Steps and strides….
What does the gait cycle that have to do with therapy or rehabilitation? Well, most people walk at some point in the day, and most have walked into your office. If people can’t carry the changes you made on the table and incorporate it into walking, then what you do will have limited effectiveness. Thus, the need for understanding the gait cycle as it relates to rehabilitation or how it can give you clues to the biomechanical faults present. An example is a loss of functional hip extension and chronic LBP/ SI dysfunction. This could be due to a myriad of reasons, from weak glutes, loss of ankle dorsiflexion, or even a dysfunctional shoulder. Understanding how these seemingly unrelated body parts integrate into the kinetic chain, especially while moving upright through the gravitational plane.
One gait cycle consists of the events from heel strike to heel strike on one side. A step length is the distance traveled from one heel strike to the next (on the opposite side). Comparing right to left step lengths can give the evaluator insight into the symmetry of the gait. Differences in step length, on the simplest level, should cause the individual to deviate consistently from a straight line (technically it should cause the individual to eventually walk in a large circle!). Often, compensations occur functionally in the lower kinetic chain to compensate for the differences in step length to ensure that you walk in a straight line. It is these longstanding complex compensations that are the generators of many of our patient’s complaints.
A stride length is the distance from heel strike to heel strike on the ipsilateral side (the distance covered in one gait cycle. Step width, or base of gait, is the lateral distance between the heel centers of two consecutive foot contacts (this typically measures 6-10 cm). Foot progression angle is the angle of deviation of the long axis of the foot from the line of progression (typically 7-10 degrees). Çhanges in the progression angle can be due to both congenital (torsions, versions) as well as developmental reasons.
Next time we will take a closer look at the gait cycle itself. Yup, we are still…The Gait Guys
special thanks to Dr. Tom Michaud, who has allowed us to use these images in our book
The pedograph as a window to the gait cycle
Have you ever studied footprints on the beach or looked at the print left by a wet foot when you get out of the water? These are some of the most primitive types of pedographs.
The pedograph, 1st described by Harris and Beath in 1947 is a rubber mat surface with multiple protruding, small grid lines on one side, which, when covered with ink, imprints an underlying sheet of paper when weight (usually a foot) passes over it. Relative plantar pressures are indicated by the size and density of the inked area, creating a “footprint” reflecting passages of force through the foot at that instance in time. They have fallen into and out of usage over the years, often discarded for more expensive technology such as pedobarographs, individual pressure sensors, and pressure sensitive mats, which have computer interfaces and can provide many useful measurements and calculations to assist the clinician with rendering a diagnosis. These systems, though more precise in some ways (provided a controlled, reproducible testing procedure) are often thousands of dollars, require a computer and the necessary skills, and have a substantial learning curve.
The pedograph in contrast is simplistic, inexpensive, and reliable and only requires that the user have an intact visual pathway and cerebral cortex and knowledge of the events occurring in the gait cycle. With some practice and a good knowledge base, the subtle nuances detected by the sensitive pedograph (nuances that can be undetected with high end computer driven plantar pressure devices) can offer information critical to a precise diagnosis and give solid clues to gait flaws and compensations. With minimal training using a pedograph, reproducible “prints” can be produced for analysis, in light of your findings clinically. They also make wonderful educational tools for your patients and clients!
An essential part of a comprehensive patient evaluation should include examination of the entire kinetic chain both in a static and dynamic fashion. Often what you see statically is either directly translated to or compensated for in the dynamic evaluation. (It is important to note that many of the available foot scan units available from orthotic companies scan a patient in a static standing position and give little information on how the feet and lower limb dynamically engage the ground during movement.) The pedograph is a useful visual tool representing a 2 dimensional image of tridimensional motion, and you are seeing the end product and compensation (or lack thereof) of the individuals mechanics at that point in time. Because of the specificity of what you are seeing refers to a particular point in time, technique and reproducibility are of paramount importance. Prints should be performed several times to insure what you are looking at is what you are looking at, and not movement artifact, because of the way the patient stepped on to or off of the mat.
With a pedograph, seeing is believing. When you have objective data about how an individual moves through space and how their joints and motor system help them to accomplish that, you have a better appreciation for the type or form of therapy which may be most appropriate. In the hands of a skilled clinician, seeing abnormal plantar pressures tells you where the biomechanical fault lies, and thus where manipulation may be appropriate, which muscles need strengthening and where neuromotor coordination is lacking and gait rehabilitation is needed.
excerpted from the 1st edition of our Book “Pedographs and Gait Analysis: Clinical Pearls and Case Studies” Trafford Publishing
How do I know if my orthotic is working?
Foot orthotics are easy, no? You get casted, it gets built, you put it in your shoe and you’re good to go, right? Wrong!
Orthotics or “Orthotic Therapy” as we call it is an ongoing process. If an orthotic is doing it’s job, your foot should change (for the better) and your prescription should become less. and less….Until you no longer need them… At least in an ideal world.
Remember, orthotics are designed to help you adapt to your environment better. Unlike a footbed, they should change the biomechanical function of your foot. A lot should go into getting fit for an orthotic, otherwise they can actually cause some of the problems they are purported to fix!
First of all, there should be a history of you and whatever is going on, with an inventory of all your past injuries. Sometimes there is a pattern that can be recognized and gives your provider clues as to what may be going on with you.
Next you should have a thorough examination of your lower kinetic chain, including the feet, ankles, knees, hips and low back. This should include range of motion, muscle strength, muscle recruitment patterns and joint function, along with reflexes, sensation and balance or proprioception. This gives us a benchmark and defines weaknesses and strengths.
Now there should be an analysis of your gait, preferably with stop motion video which allows us to slow down movements and assess subtle abnormalities that may not be visible during normal speeds of movement. If you are there for cycling orthotics, then a video of your stroke pattern is made. Sometimes, footage of your skiing technique can be helpful as well.
At this point, it should be obvious to both you and your orthotic provider whether or not an orthotic is needed. If so, a non weight bearing cast in terminal stance phase (This is a specific position of your ankle and foot) should be performed. This is usually followed by the prescription of appropriate stretches and exercises, specific to your condition. Shoe recommendations should also be given, since different foot types require different footwear characteristics. This will be good news for the ladies who like many shoes. Most guys just want the pain to stop and won’t care what they look like, as long as they are not pink!
Now you have an idea of what goes into (or should go into) building the perfect orthotic for you. Ask lots of questions of whoever is building them for you and make sure they are answered to your satisfaction. They should be a stepping stone to your recovery and not a crutch for you to depend on.
Telling it like it is, we are… The Gait Guys
