Along the lines of Friday Follies and our earlier post, here a funny acupuncture commercial for you.
Have a great weekend
Ivo and Shawn
A Great Reference Text:
Biomedical Acupuncture for Sports and Trauma Rehabilitation
Dry Needling Techniques,
Yun-tao Ma, Elsevier, 2010
Both Dr Allen and Dr Waerlop have studied under Dr Ma and Dr Waerlop has had the privilege of teaching with Dr Ma (Dr Waerlop is one of the leading acupuncture instructors in the US and one of the few Dry Needling Instructors)
This book is a follow up to Dr Ma’s 1st book: Biomedical Acupuncture for Pain Management.
They are both great resources for the Western approach to needling for pain management and dry needling, explaining the physiological mechanisms behind both.
Dr Waerlop uses acupuncture extensively for muscle stimulation and facilitation in many gait related disorders, and finds it a valuable adjunct to therapeutic exercise.
The Gait Guys
You can download many lectures on acupuncture by Dr Waerlop and many videos by Drs Allen and Waerlop on rehabilitation and gait, as well as basic science here.
Acupuncture can be effective for many types of sports injuries and rehabilitation of gait related disorders. One such study can be found here.
The effect of needling is though to be 3 fold: local, segmental and cortical.
The local effect of needling occurs at the site of the needle insertion. Local tissue damage causes cytokines to be released and this stimulates both the inflammatory and healing process, as well as increasing local circulation.
The segmental affect is thought to be at the spinal cord level (the dermatome or sclerotome) where inhibition of pain impulses occur (pre synaptic inhibition for you neuro nerds out there)
The cortical or “long loop” effect is thought to be due to activation of higher brain centers which cause descending inhibition of pain and activation of the hypothalamic-pituitary axis (which appears to be one of the reasons acupuncture can be effective for colds and other problems).
You can view many of our posts on pain and its physiology here to gain a better understanding of the pain pathway and pain modulation.
The Gait Guys: yes, sometimes we are a pain, but we offer solutions to help and give you the research to back it up
Why do we have difficulty with our gait when we drink too much alcohol ? It is not unlike the disturbed sense of balance we experience when we have an inner ear problem such as an infection.
Alcohol affects one’s balance by changing the viscosity of the endolymph within the otolithic membrane, the fluid inside the semicircular canals inside the ear. The endolymph surrounds the cupula which contains hair cells within the semicircular canals. When the head is tilted, the endolymph flows and moves the cupula. The hair cells then bend and send signals to the brain indicating the direction in which the head is tilted. By changing the viscosity of the endolymph to become less dense when alcohol enters the system, the hair cells can move more easily within the ear, which sends the signal to the brain and results in exaggerated and overcompensated movements of body. This can also result in vertigo, or “the spins." Many of us have experienced this event in one shape or another and we know what it feels like. The unsteadiness of our gait is disturbing and uncorrectable until the problem is solved or the alcohol’s effect wear off. In chronic alcoholism however, the problem is different and more lasting.
Disturbed gait and balance are among the most consistent sequelae of chronic alcoholism. Research studies have shown evidence that partial recovery of gait and balance functions in alcoholics may be achieved with abstinence. This study ( http://www.ncbi.nlm.nih.gov/pubmed/21919921) showed that alcoholics’ gait and balance can continue to recover with long abstinence from alcohol, but that deficits persist, especially in eyes-closed standing balance.
http://www.sciencedaily.com/releases/2011/09/110915163519.htm
Chronic alcohol abuse consistently damages the cerebellum. The cerebellum has multiple functions, including control of balance and coordination and even motor pattern generation. Alcohol also damages subcortical white matter, the myelinated fiber tracts that connect different parts of the cortex, and other central nervous systems. Long-term alcohol dependence also results in impaired dopamine transmission in the striatum, an important area for motor control.
The next time you are the designated driver, spend some time appreciating the subtle nuances and changes in people’s gait. Not only is it amusing, but fascinating as well.
Studies quoted in this blog post.
(Smith and Fein, 2011, Alcohol Clin Exp Res 35:2184–2192)
http://www.ncbi.nlm.nih.gov/pubmed/22691134
Gait and Balance Deficits in Chronic Alcoholics: No Improvement from 10 Weeks Through 1 Year Abstinence
Teleseminar on Gait→
/Wed TeleSeminar this week! Jul 11th, 2012 8:00 PM Eastern Time
Title: Chiropractic TeleSeminar Biomechanics 309
Location: 1 hr by telephone
Instructor: Waerlop/Allen, DC
Price: 19.00
Join Drs. Waerlop and Allen for this live seminar by telephone conference call with web interface. Lots of great video’s - always gets great feedback!
Neurocognitive Control in Movement Perception and Control
You have read our blog posts on how much we respect and admire those that engage in complex motor tasks like gymnastics, martial arts, parqour, dance and others. The more complex the task the greater the rewards on several levels.
We found yet another article supporting multiple levels of sensory-motor advancement, in this article’s case, dance however it applies broadly across all complex motor tasks. We have also included another video with dub dancer Marquese Scott with this blog post. You may recall our prior writing with him, link here where we talked briefly about “foot edge work”. The above video is another demo of Marquese doing what he does best, making complex motor tasks look simple.
Neurocognitive control in dance perception and performance.
Acta Psychol (Amst). 2012 Feb;139(2):300-8. Epub 2012 Jan 9.
Department of Sport Science, Bielefeld University, Germany. bettina.blaesing@uni-bielefeld.de
Abstract: Dance is a rich source of material for researchers interested in the integration of movement and cognition. The multiple aspects of embodied cognition involved in performing and perceiving dance have inspired scientists to use dance as a means for studying motor control, expertise, and action-perception links. The aim of this review is to present basic research on cognitive and neural processes implicated in the execution, expression, and observation of dance, and to bring into relief contemporary issues and open research questions.
__________________________________________
What The Gait Guys have to say:
The abstract review above addresses six issues they discovered and investigated in dancers:
1) dancers’ exemplary motor control, in terms of postural control, equilibrium maintenance, and stabilization;
2) how dancers’ timing and on-line synchronization are influenced by attention demands and motor experience;
3) the critical roles played by sequence learning and memory;
4) how dancers make strategic use of visual and motor imagery;
5) the insights into the neural coupling between action and perception yielded through exploration of the brain architecture mediating dance observation; and
6) a neuroesthetics perspective that sheds new light on the way audiences perceive and evaluate dance expression.
As you have read from some of our previous blog articles, we have some experience in dance. We do this to make sure we are always pressing the edge of human sensorymotor development and learning. Dance has been one of the most complex body movement endeavors we have undertaken, more difficult than many of the complex movements in various sports. This is why we never have a problem recommending dance, gymnastics and pilates to our young patient’s parents who want their children to excel in any given sport. Fast, precise, assured and efficient foot work will take one far in athletics. It is why in basketball they talk so much about the importance of the first step off a dribble when confronting an opponent. The first step, when fast, precise, assured and efficient, will leave one’s opponent stunned and motionless as their savvy opponent effortlessly passes them by. Nothing teaches these foot skills better than dance in our experience. Just as Marquese displays above, mastering complex footwork leads to advanced body movement possibilities. And possibilities in sport are what separate the great from the good. The 6 points discussed above namely exemplary motor control, in terms of postural control, equilibrium maintenance, and stabilization, timing, on-line synchronization, sequencing of learning and memory, the advantages of strategic use of visual and motor imagery, the insights into the neural coupling between action and perception are all major advantages to the athlete who can put them into play at a higher level. And the more complex cross training of tasks that occurs, the greater likelihood that these issues are what will allow the cream to rise to the top in sport.
The Gait Guys
Gait Pathomechanics: Walking in a Pencil Skirt.
If you want more on this topic, Drs Allen and Waerlop go on a fun and informative rant on fashion, pencil skirts and high heeled shoes on Podcast # S1-E3 (Season1-Episode3), a soon to be released podcast episode.
Who knows why this video is even on Youtube. It is 6 minutes of this gal walking back and forth, so do not watch more than the first 60 seconds for anything exciting, trust us. Read the blog post and then come back to the video and see what we talk about. There are some severe gait compromises in a skirt like this, let alone with the high heel shoes accompanying the gait.
According to wikipedia:
The slim, narrow shape of a pencil skirt can restrict the movement of the wearer so pencil skirts often have a slit at the back, or less commonly at the sides. Sometimes a pleat, which exposes less skin, is used instead of a slit. The classic shoes for wearing with a pencil skirt are high heels,[3] with sheer stockings or tights. The predecessor to the pencil skirt is the hobble skirt, a pre-WWI fad inspired by the Russian Ballet. This full-length skirt with a narrow hem seriously impeded walking. The French designer Christian Dior introduced the classic modern pencil skirt in the late 1940s. The pencil skirt feels different from looser skirts, and can take some adjustment by the wearer in terms of movement and posture in order to manage it successfully. Walking needs to be done in short strides; entering and leaving a car gracefully takes practice; and when sitting the legs are held close together which some find restrictive (though others like the feeling of their legs being “hugged” by the skirt). Activities such as climbing ladders and riding bicycles can be very difficult in a pencil skirt. The pencil skirt is warmer due to the reduced ventilation, and is less likely to be blown up by gusts of wind.
The Gait Guys dialogue on pencil skirts :
Tie a rope or theraband around your knees, you will suddenly experience the short cute steps that this gals does devoid of almost all hip flexion and hip extension, both serious gait cycle restrictions.
Without hip flexion-extension the entire timing of the swing phase is off. No longer can there be adequate use of the obliquity of the pelvis and thus abdominals or contralateral leg swing to initiate supination and toe off.
Step and stride lengths are dictated by the tightness of the roap, and in this case the diameter and give of the bottom of the skirt. Not to mention the bloody complication added by the high heels !
- There is an unnatural oscillation of the pelvis due to the restrictions mentioned above.
The Pencil skirt: Never again will you be able to wear one and not notice its gait impairments. Nor will men be able to just watch the ladies in the skirts for the appreciation of beauty and style. Men, you will have much more to study now, you just may hate us for your undying need to evaluate the biomechanics in skirt wearers forevermore ! Just be sure you do not abuse this new evaluation superpower as an excuse to your spouse to watch girls walk by. We are not responsible for abuses of acquired superpowers. And although we many have actually just become your new heros, just remember, with great powers come great responsibilities.
Once the website launches you will find our new product, “pencil skirt training noose” on our online store. $50 for the finest of roap loops !
There is so much more on this topic in Podcast #3 . Be sure not to miss it. We will launch it here on the blog and on our Facebook page and in iTunes once we get permissioned by Apple.
Shawn and Ivo, your new superheros of gait. Gait Fashonistas, perhaps we have a purpose and calling in the fashion industry !
Podcast #1: S1E1 (Season 1, Episode 1)→
/OK gang, here we go ! They are finally launched !
THE GAIT GUYS EXPERIENCE PODCAST has arrived !
http://thegaitguys.libsyn.com/ (click on the small circle beside the word “Pod” beside the title)
Please be patient while we work out the audio bugs over the first 2-3 podcasts (there is some irritating reverb on this first one). We have new studio quality mics on the way, better sound cancelling earphones and we are looking at some compressors and what not to get the sound quality up. It is hard doing this through a virtual studio separated half way across the country. So, be patient with us for this brief time.
But most of all, Enjoy !
*** IMPORTANT: There are 2 links below.
Be sure to click below to grab our RSS feed so you never miss a podcast. The second link below will have our session notes for the podcast so you can see the topics at hand, follow the case studies, and have all links to videos, articles at your disposal so you do not have to reach for a pen to jot them down. All you have to do is listen and enjoy ! If you have emailed us questions or presented us with your case problems, you will find most if not all of your email typed out (ID protected of course) in the session notes.
We have pods 2-4 done already. The have better stories and we have worked out some of our anxieties about screwing up an hour long recorded mid way ! So, give us a few listens before you start firing off recommendations. We will want them, but most of the bugs on the first 2-4 podcasts you will find resolved. So by podcast 5 we will want your input and feedback !
http://thegaitguys.libsyn.com/rss
Here is a website where all of our podcasts will be housed and launched from. You can find all of our session notes here as well.
http://thegaitguys.libsyn.com/
We will have this all shipped over to iTunes soon so you can load them up to your ipod and mp3 players to we can be a part of your journey into work every day, or hand out with you while you cut the lawn, cook dinner or whatnot. So, Hang tight ! It is all coming.
PS: we talk about the website launch in this first podcast. It is next on our list. It is 95% done. Hang tight !
Now, if we could just quit our day jobs we would have had all this done long ago !
Thanks for your patience everyone !
Being on the airwaves we are now one step closer to intergalactic domination !
Shawn and Ivo, The Gait Guys
Is Barefoot more economical ?→
/Researchers at England’s Northumbria University analyzed the gait and oxygen uptake of 18 recreational and elite runners performing a series running tasks both barefoot and shod.
Dr. Michael Wilkinson, lead researcher and avid barefoot runner determined the following in their study:
- a significant saving in energy from taking off running shoes
- mechanical differences in the foot strike patterns (shod runners did more heel strike, unshod were more midfoot striking)
- there were immediate foot strike changes in previously shod runners who suddenly changed to unshod foot strike
- there is less oxygen use during barefoot running compared to running shod at the same speed. Hence improved running economy.
Characteristically, skilled unshod runners have a distinctive running gait utilizing:
- mid-foot landing
- shorter stride lengths
- faster stride rates
- reduced ground contact time
- lower impact force and loading rates which dampens injury inducing forces
- reduced oxygen utilization. The 6% improvement in economy was the same as that previously reported after a nine-week training program for shoe-wearing runners, who also enjoyed a 3% improvement in running performance.
Click on the link above for the Science article.
YET MORE compensations for short legs…
We remember from from the last few weeks, there at least SIX common compensations for a short leg. Last week we looked at hip hiking. Here is the list, in case you needed a reminder:
- hip hike on long leg side (seen as contraction of hip abductors, obliques and quadratus lumborum on short leg side)
- excessive knee bend on the long leg side
- pronation of the longer side, supination of the shorter
- leaning to he shorter leg side
- circumduction of the longer leg around the shorter
- excessive ankle plantar flexion on short side
This time we will look at excessive knee bend on the long leg side. Normally the knee bends about 20 degrees at loading response/ midstance, and about 50 degrees during swing phase to create “clearance”.
Watch this gals R knee during swing. Yes, she has an abnormality of the R great toe extensor (torn extensor hallicus longus and brevis), but also a L short leg. It makes no difference if the leg is functionally or structurally short, the body still needs a strategy to move around the longer leg.
Remember here is that what you are seeing is the compensation, not necessarily the problem. When one leg is shorter, something must be done to get the longer leg through swing phase.Excessive knee flexion. Yet another compensation to look out for.
Ivo and Shawn. …still bald…still good looking…still geeky…… The Gait Guys
More research on Forefoot Running: Forefoot Varus and the toe extensor muscles.
/Lately we have all seen much in the news about the forefoot strike loading in runners and many of the proposals and rebuttals regarding injury rates. Our dialogue less than 2 weeks ago on some of Lieberman’s recent comments (our blog article “Dear Dr. Lieberman”, click here) seem to be ringing true again. Here are just two more insightful and important studies when it comes to looking at some of the proposed ideas and causes of forefoot varus. Naturally, a thinking mind would wonder if some of these weaknesses in anterior and posterior tibialis muscles as well as extensor toe musculature, as proposed in just these 2 articles, are causal to the forefoot injuries that seem inevitable as Lieberman seems to suggest (again, see our blog post). Naturally, weaknesses and poor motor patterns of some or all of these muscles is going to create and insufficient and possibly inefficient and pathologic forefoot loads because of the forefoot varus foot type these muscular imbalances can functionally produce. We have been pounding sand on this issue for years but still no one listens. The medial research, as evidenced here is supportive of our theories and everyday clinical findings.
To summarize, ONCE AGAIN, not everyone is suited or possibly ready for forefoot load/contact/strike running. And if you have injury or problems in doing so, don’t blame your minimalist shoe……. it is either a foot type that needs functional repair or a foot type that is fixed an must opt for midfoot strike.
There is SO MUCH MORE to this game than just strap on some minimalist shoes and start forefoot loading your way on your next run. Buyer beware !
Shawn and Ivo…….. the gait guys……..two guys who are “Gandhi’d” regularly.
“First they ignore you, then they laugh at you, then they fight you, then you win.”
- Mahatma Gandhi
______________________________________________
http://www.ncbi.nlm.nih.gov/pubmed/20307453
Foot (Edinb). 2009 Jun;19(2):69-74. Epub 2008 Dec 31.
Foot varus in stroke patients: muscular activity of extensor digitorum longus during the swing phase of gait.
Reynard F, Dériaz O, Bergeau J.
Clinique romande de réadaptation, SUVA Care, Av. Gd-Champsec 90, Sion, Switzerland. fabienne.reynard@crr-suva.ch
Abstract
CONCLUSIONS: The activity of extensor digitorum longus muscle during the swing phase of gait is important to balance the foot in the frontal plane. The activation of that muscle should be included in rehabilitation programs.
_______________
http://www.ncbi.nlm.nih.gov/pubmed/16882899
J Bone Joint Surg Am. 2006 Aug;88(8):1764-8.
The contributions of anterior and posterior tibialis dysfunction to varus foot deformity in patients with cerebral palsy.
Michlitsch MG, Rethlefsen SA, Kay RM.
Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
Abstract
RESULTS: The muscular contributor to varus deformity was the anterior tibialis in thirty feet, the posterior tibialis in twenty-nine feet, both the anterior tibialis and the posterior tibialis in twenty-seven feet, and another contributor in two feet. Seventy feet had varus deformity during both stance phase and swing phase. Of these seventy feet, twenty-five exhibited dysfunction of the anterior tibialis, twenty exhibited dysfunction of the posterior tibialis, and twenty-three exhibited dysfunction of both muscles. Therefore, the timing of varus was not predictive of the contributing muscle or muscles.
CONCLUSIONS: The current study demonstrated a higher prevalence of anterior tibialis dysfunction, both alone and in combination with posterior tibialis dysfunction, as a contributor to pes varus in patients with pes varus and cerebral palsy than had been reported previously. Dynamic electromyography provides clinically useful information for the assessment of such patients.
Foot Strike of Women for the Olympic Time Trials:
This picture comes from Iain Hunter at BYU: http://biomechanics.byu.edu/. We found it on Peter Larson’s Blog: Runblogger.com http://www.runblogger.com/2012/06/foot-strike-patterns-of-men-and-women.html
Here are some of our thoughts:
It would have been nice to see each of these in turn on video for further analysis; What this shows are a few things;
- People who are at this level and run fast have different foot strike patterns, this type of foot strike does not always equal the fastest times (though the top 3 were mid foot strikers, something we work with our athletes to achieve)
- 7 (and 1 DNF) were midfoot strikers
- 4 were forefoot strikers
- 11 were heel strikers
- many runners has asymmetrical strikes, depending on side (4)
- 4 of these runners seem to have a significant varus in either their fore foot or rear foot. However this is difficult to truly tell from such small single snapshot pictures. And just because it appears to be a varus landing does not mean that it is true on examination, a foot that has reduced peroneal activity can appear to have a varus strike, but that does not truly then comment on a true forefoot varus. Also, remember from our previous posts, if a runners is employing a notable degree of cross over gait technique the approach of the foot to the ground and at the ground can appear to be forefoot varus. * These are critical points, because what you see is not necessarily what you truly have. There are possibly many variables playing out.
- shoes which have green on them are more popular (7)
- Neither Shawn nor Ivo could run a 10K and have a chance against any of these folks
Have a great Saturday
Ivo and Shawn
A Cure for Smelly Feet?
Welcome to foot odor Friday. Today’s Theme: You guessed it!
Here’s one paper we though had merit (sure, go to Pub Med and search foot odor. There were 119 entries). We think we may try this in the office…
The Gait Guys: Yes, smelly feet are something we have to deal with at the office on a daily basis. One of the pitfalls of being a Foot Geek : )
Make sure to check back later for more on malodorous extremities…
J Int Soc Sports Nutr. 2007 Jul 13;4:3.
A novel aromatic oil compound inhibits microbial overgrowth on feet: a case study.
Source
West 1140 Glass Avenue Spokane, Washington, 99205, USA. drbill@omnicast.net.
Abstract
ABSTRACT:
BACKGROUND:
Athlete’s Foot (Tinea pedis) is a form of ringworm associated with highly contagious yeast-fungi colonies, although they look like bacteria. Foot bacteria overgrowth produces a harmless pungent odor, however, uncontrolled proliferation of yeast-fungi produces small vesicles, fissures, scaling, and maceration with eroded areas between the toes and the plantar surface of the foot, resulting in intense itching, blisters, and cracking. Painful microbial foot infection may prevent athletic participation. Keeping the feet clean and dry with the toenails trimmed reduces the incidence of skin disease of the feet. Wearing sandals in locker and shower rooms prevents intimate contact with the infecting organisms and alleviates most foot-sensitive infections. Enclosing feet in socks and shoes generates a moisture-rich environment that stimulates overgrowth of pungent both aerobic bacteria and infectious yeast-fungi. Suppression of microbial growth may be accomplished by exposing the feet to air to enhance evaporation to reduce moistures’ growth-stimulating effect and is often neglected. There is an association between yeast-fungi overgrowths and disabling foot infections. Potent agents virtually exterminate some microbial growth, but the inevitable presence of infection under the nails predicts future infection. Topical antibiotics present a potent approach with the ideal agent being one that removes moisture producing antibacterial-antifungal activity. Severe infection may require costly prescription drugs, salves, and repeated treatment.
METHODS:
A 63-y female volunteered to enclose feet in shoes and socks for 48 hours. Aerobic bacteria and yeast-fungi counts were determined by swab sample incubation technique (1) after 48-hours feet enclosure, (2) after washing feet, and (3) after 8-hours socks-shoes exposure to an aromatic oil powder-compound consisting of arrowroot, baking soda, basil oil, tea tree oil, sage oil, and clove oil.
CONCLUSION:
Application of this novel compound to the external surfaces of feet completely inhibited both aerobic bacteria and yeast-fungi-mold proliferation for 8-hours in spite of being in an enclosed environment compatible to microbial proliferation. Whether topical application of this compound prevents microbial infections in larger populations is not known. This calls for more research collected from subjects exposed to elements that may increase the risk of microbial-induced foot diseases.
MORE compensations for short legs…
We remember from 2 weeks ago, the week before, AND last week, there at least SIX common compensations for a short leg.
We spoke about circumducting the long leg last time. Once again, here is the list
- pronation of the longer side, supination of the shorter
- leaning to he shorter leg side
- circumduction of the longer leg around the shorter
- hip hike on long leg side (seen as contraction of hip abductors, obliques and quadratus lumborum on short leg side)
- excessive ankle plantar flexion on short side
- excessive knee bend on the long leg side
Lets look at “hip hiking” of the longer extremity today. Hiking the hip allows one to create enough room (hopefully) to get that long leg through without dragging on the ground. Again, it makes no difference if the leg is functionally or structurally short, the body still needs a strategy to move around the longer leg.
This gal in the video has cerebral palsy (CP), affecting the left side. She has a short R leg and hikes the L pelvis pelvis up to get it to clear (she has L g med weakness due to the CP)
Watch the above video a few times to see what we are talking about. You can really see it when she is walking toward you.
Remember here is that what you are seeing is the compensation, not necessarily the problem. When one leg is shorter, something must be done to get the longer leg through swing phase.
Hip Hiking. Not quite the “Walk in the Woods” Bill Bryson was talking about, but yet another compensation for a short leg.
Ivo and Shawn. …bald, good looking, geeky…… The Gait Guys
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.
