Spring is here and Dr Ivo Waerlop of The Gait Guys talks about some common problems seen due to manufacturers defects in cleats and how they can affect athletes. From uppers put on the outsole incorrectly and contributing to and potentiating rearfoot varus and valgus to poor cleat placement affecting the 1st mtp mechanics; they all contribute to athlete performance.
Welcome to rewind Friday, Folks. We always seem to be talking about bunions, and receive quite a few questions on them. This brief video discusses where they come from.
The Importance of the “Toe Box”
In this brief video, excerpted from the National Shoe fit Training Program, Shawn and Ivo talk about the importance of adequate toe box size and how to relates to fit. Enjoy!
all material copyright 2012. all rights reserved
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1- neuroscience story
What do dolphins and sleep walking have in common?
Do ultra marathoners sleep while they run ?
Join us for the podcast neuroscience introduction.
2- More lectures available on www.onlineCE.com 13 hours of courses there ! Go there and look up our lectures
3- OFF TOPIC Discussion:
So many of them supinate and have a wide tripod…….
Julio C, in Sao Palo Brazil !
5- EMAIL Question:
6- EMAIL CASE:
Guys, love you, love your show
Anyhow…….enough ego stroking…….
What is your take on the biomechanical implications of a short quadriceps muscle in gait ?
7- Pedographs or software ???? what is our take ?
8- EMAIL CASE
You talked about it several blog posts but i would love to hear you expand upon it.
Is it true that walking in flip flops is bad for you? I’ve heard a lot of “experts” say it will cause your arches to fall. Thanks! - Norma
Neuromechanics Weekly: How does appropriate movement diminish pain?
We talk about proper (or should we say appropriate) movement (including gait) inhibiting or diminishing pain. So, how does that happen?
Above on the left is a great diagram that we will work through.
You are looking at a cross section of a spinal cord (We can hear the groans already!) We remember that the dorsal horn (posterior part) is sensory and the ventral horn (front) is motor. In between them (the lateral horn) is autonomic (this runs automatized body functions such as your heart, lung, guts, etc).
Small nerve fibers subserve pain. These are the A delta and C nerve fibers. “Small” refers to fiber diameter of the nerve. These nerves are where pain stimuli enters the spinal cord; they enter the sensory dorsal horn and synapse/connect there with the next neuron in line that takes the sensory message up the spinal cord to the brain to tell you about the pain including its intensity, location etc. Pain can result from tissue damage or injury (which can be due to, or the result of, poor biomechanics).
Large diameter nerve fibers subserve sensations like touch, pressure, vibration, muscle spindles (muscle length) and golgi tendon organs (muscle tension/load). These fibers also enter the sensory dorsal horn, but they do not synapse immediately, unlike pain fibers. They ultimately travel up to the top of the brainstem or cerebellum to coordinate information with other data your brain is processing. They send a branch (or collateral) to an inhibitory neuron, which excites the inhibitory neuron. Thus, if you excite an inhibitory neuron, it does it’s job and inhibits the propagation of an impulse. In this case, it inhibits the pain impulse from traveling to the cortex. So pain is inhibited. Appropriate biomechanics excite the largest population of receptors and provide the most effective response.
Now look at the diagram on the right. It is a simplified schematic of the one on the left, with detail of the connections. Note that the LARGE FIBERS (from joint mechanoreceptors, spindles, muscles, etc) EXCITE the inhibitory interneuron (which would inhibit it). Also note that the SMALL FIBERS INHIBIT the inhibitory internuron (which would excite it!)
There you have it. Clear as mud? Go through some of our old posts on receptors and FEEL THE PAIN (parts 1, 2, 3+4) and come back to this and read it again. You know you want to be a geek, so go ahead!
The Gait Guys: Geeks on many levels. helping you to presynaptically inhibit pain on a daily basis, through better movement.
You have heard us talk about weakness (short weak and tight weak) muscles all the time on Youtube: The Gait Guys; now here is the neurology behind it. Think about this concept the next time you see a gait compensation and think of the muscles (agonists/antagonists) involved.
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
Here is some classic Shawn and Ivo, talking about rearfoot varus in one of our older “Manual Medicine Advisor” Podcasts. Sit back and enjoy!
Gait, Running and Muscle fiber types & Why you want to train to mimic your sport.
This weeks neuromechanics explores muscle fiber types, the characteristics of each, and what that means for training. How does that relate to gait?
Our lower extremity muscles are a mix of strength and endurance muscles and each must be trained (or retrained) appropriately. If you lack endurance capacity in your gluteus medius (commonly seen with fatigue and manifesting as a pelvic dip), strength training will not help the problem… in fact, it will make it worse! Larger cross sectional area with less mitochondria, fewer capillaries and less myoglobin only fuels more anaerobic glycolysis (read LACTIC ACID PRODUCTION); if you cannot recycle this appropriately, your endurance goes down. Remember, exercise is specific as to the type of contraction (isometric, isotonic, isokinetic) as well as the speed of contraction.
Have your attention? Watch the video!
We Are and will remain The Gait Guys: piecing it together so you don’t have to.
How long does it take for training improvements to occur ? In today’s neuromechanics weekly video, Dr Waerlop talks about how long it takes for training effects to show effect, and how much of the early strength gains are due to neurological efficiency, rather than muscular hypertrophy. This is why we can all make such dramatic changes in gait in such short periods of time!
Power of Splay: New and improved
This time with some anatomy pix.
Think about triangles. Hey Pythaogoras did! They are powerful distributors of force. Here we will talk about 3 of them.
There are 4 layers of muscles in the foot. The 1st triangle occurs in the 1st layer. Think of the abductor hallucis and the abductor digiti minimi. Proximally they both attach to the calcaneus and distally to the 1st and 5th proximal phalanges. Now think about the transverse metatarsal ligament that runs between the disal metatarsal heads. Wow, a triangle! this one is superficial.
Now think about the adductor hallicus. It has a transverse and oblique head. think about that transverse metatarsal ligament again. Wow, another triangle!
What about the flexor hallicus brevis and flexor digiti minimi? The former originates from the cuboid, lateral cunieform andd portion of the tib posterior tendon; the latter from the proximal 5th metatarsal. They both go forward and insert into the respective proximal phalynx (with the sesamoids intervening in the case of the FHB). and what connects these? The deep transverse metatarsal ligament of course! And this triangle surrounds the adductor triangle, with both occurring the 3rd layer of the 4 layers of foot muscles.
Triangles… and you thought geometry was boring!
Remaining triangular when we need to (because of our pointy heads)…Ivo and Shawn
Some inspiration for a Sunday. This is one of our all time favorites! When the world has you down…go for a run
Ivo and Shawn
We are often asked “What is wrong with this gait?” or “Why do I have pain?”. Sometimes, we are able to provide an explanation which seems too simple, but is often correct. It often corrects the immediate problem, only to have another crop up a few weeks later.
To paraphrase from the words of SHREK; peoples compensations are like onions; they have layers. Uncovering and remedying one problem often leads us to the next weakest link in the chain.
We still have fond memories of Dr Ted Carrick grilling us in the post graduate neurology program “What is the longitudinal level of the lesion? Most pathologies occur at one locus; if you diagnose more than one, it is usually due to metastasis, multiple vascular occlusions, or clinical incompetence. Is the lesion at the receptor, the effector, the peripheral nerve, the spinal cord, the brainstem, the thalamus, the cerebellum or cerebrum”.
The information to glean here is that often we need to establish and limit our focus to ONE area where the problem could be. This necessitates us thinking through the problem and coming up with ONE problem which could cause all the problems you are seeing. This applies to gait and motion assessment as well.
Think of the patient with r sided knee pain caused by patellar tracking issues. Is the retro patellar inflammation the cause? Not usually (unless there has been direct trauma), it is often the symptom (or compensation). Maybe the cause is a forefoot varus deformity because they cannot descend the 1st ray adequately. Maybe this is due to insufficient extensor hallicus brevis function, or is it the peroneus longus? Maybe it is due to a congenital deformity of the foot. Maybe it is due to a functional (or anatomical)leg length discrepancy. Or maybe it is a problem with the left shoulder…you get the idea.
Keep looking and digging until you have found the 1 THING that can explain what is going on. Maybe it’s the individual; maybe it’s their footwear. maybe something else. If you can’t explain it by a single problem or fault, maybe it is time to run some blood work, send them for a vascular flow analysis, or more often than not; expand our knowledge base.
We are the Gait Guys. Two guys digging deeper and looking for the cause.
What does the Reticular Formation have to do with gait?
Have you ever worn flip flops? What do you need to do to keep them on? Clench (flex) your toes (specifically your flexor digitorum and flexor hallicus longus). What does that have to do with gait?
Take off your shoes (hopefully you showered); reach inside (unless there is something growing in there) and pull out the removable insole. Look at it. See those toe marks? Looks like someone has been clenching their toes again! So what?
This video exemplifies why flexor dominance (you have heard us say it many times) inhibits extensor activity. The upper part of the reticular formation fires the extensors, but the lower part inhibits them AND the corticospinal tract (basically the motor pathway you use to fire most of your voluntary flexors) stimulates the lower reticular formation (which inhibits the extensors). Many pathologies are because of flexor activity, and his is one of the pathways that’s facilitates that pathway. The key to fixing many problems? Fire the extensors! (And stay out of flip flops)
The Gait Guys….figuring it out and explaining it to you in terms that make sense. And no, we do not own any flip flops….
Don’t let the title scare you. While watching this excerpt from an acupuncture lecture, think about the implications for gait.
In this installment of Neuromechanics weekly, we discuss how everything we do, smell, see or hear influences muscle tone through the cerebellum. The take home message is environmental cues as well as therapeutic ones will influence muscle tone via the muscle spindles..
You just can’t get away from neurology. It is EVERYWHERE!
In this Neuromechanics weekly, Dr Waerlop Introduces the cerebellum and talks about its importance clinically, since it contains more than ½ of the neurons in the brain! It’s anatomy and inputs from the periphery are discussed. The take home message is the cerebellum is the key to understanding and directing movement, since it receives feedback from most ascending and descending pathways.
You evidently can’t have your cake and eat it too…
Here is more research to show that running in shoes give you a mechanical advantage in force generation, but at the cost of increased stress on the knees.
“The results imply higher mechanical stress in shod running for the knee joint structures during midstance but also indicate an improved mechanical advantage in force generation for the ankle extensors during the push-off phase.”
No surprise really. You could swing a broomstick with little effort and a baseball bat with more effort, but which will hit the ball farther? Which may tax your shoulder more?
Whenever we take a foot, that SHOULD supinate, effectively decrease its mobility (making it stiffer) and MAKE IT supinate, we will have more power. Remember P = W/t? P is power, W is work and t is time. W is also F X s, where F is force and s is displacement; so we have P= Force X displacement/time. We are increasing displacement here: with force and time remaining unchanged, we have more power.
But…all things wear out in time with use; including your joint cartilage. Hmmm, maybe we reduce the force and allow the joints (like the ankle) to displace (we see increased displacement in unshod running) and we run into our 100’s.
The choice is yours.
The Gait Guys: 2 docs, making a difference, one step at a time.
Institute of Biomechanics and Orthopaedics, German Sport University Cologne, Germany. firstname.lastname@example.org
The objective of the study was to investigate the adjustment of running mechanics by wearing five different types of running shoes on tartan compared to barefoot running on grass focusing on the gearing at the ankle and knee joints. The gear ratio, defined as the ratio of the moment arm of the ground reaction force (GRF) to the moment arm of the counteracting muscle tendon unit, is considered to be an indicator of joint loading and mechanical efficiency. Lower extremity kinematics and kinetics of 14 healthy volunteers were quantified three dimensionally and compared between running in shoes on tartan and barefoot on grass. Results showed no differences for the gear ratios and resultant joint moments for the ankle and knee joints across the five different shoes, but showed that wearing running shoes affects the gearing at the ankle and knee joints due to changes in the moment arm of the GRF. During barefoot running the ankle joint showed a higher gear ratio in early stance and a lower ratio in the late stance, while the gear ratio at the knee joint was lower during midstance compared to shod running. Because the moment arms of the counteracting muscle tendon units did not change, the determinants of the gear ratios were the moment arms of the GRF’s. The results imply higher mechanical stress in shod running for the knee joint structures during midstance but also indicate an improved mechanical advantage in force generation for the ankle extensors during the push-off phase.