About 8 years ago (?) I was in my Muscle Activation Class (MAT) here in Chicago and somewhere during the course of the class the topic came up about problems with the big toe. This really nice fella spoke up about a major injury to his thumb (the ph…

About 8 years ago (?) I was in my Muscle Activation Class (MAT) here in Chicago and somewhere during the course of the class the topic came up about problems with the big toe. This really nice fella spoke up about a major injury to his thumb (the photo is not of him but here is a link to this fella’s story) and how doctors then proceeded to amputate his big toe to replace the thumb.

Gosh, with my brain knowing all that it does about gait as well as hand function, thoughts began to swim in every direction. What would I do if I were presented with the same scenario?  Without my thumb my work as a manual medicine physician would definitely be changed. But, heck, my gait would forever be changed too! I would be sentenced to a life of never ending gait compensations that could never be treated. My mind swirled around impaired hip extension and gluteal dysfunction, not to mention:

  • foot tripod incompetence
  • pronation and supination dysfunction guaranteed
  • virtually guaranteed hammer toe formation
  • metatarsal stress impacts
  • inappropriate loads on the medial column stabilizers such as the tibialis posterior now that the medial foot tripod was impaired let along the new absence of the long and short toe flexors that often provide compensatory activity to help an insufficient medial tripod.
  • impaired ipsilateral and contralateral arm swing
  • impaired shoulder function
  • core and hip impairments and asymmetry
  • the list goes on and on……. perhaps for hours !  We could do a whole 1-2 hour lecture just on the gait compensations and the subsequent motor impairment patterns that would ensue.

Seeing this photo and reading this fella’s story brought my mind back to the swirling thoughts I had while sitting in that lecture hall that day. And now some 8+ years later i am still brought to the same uncertain conclusion.  Would I go for the switcheroo ?   The transplant isn’t guaranteed successful, if it was that might sway things a little. But the gait impairments are guaranteed. 

What would  you do ? 

We hope you ( and us here at The Gait Guys) never are confronted with this most difficult presentation.  However, in just a few years, with the advent of 3D printers the anxiety of this issue is likely going to become a non-issue.

Just some food for thought today.  Or maybe we should have said “Foot for thought.”

Shawn and Ivo

Orthotics and Footbeds. What's the difference?

Orthotics and footbeds, they’re the same thing, right? This is a question that is posed to us all the time.  No, they’re not the same, but oftentimes one or the other can be appropriate. To explain the difference, we need to understand a little bit about foot mechanics.

The foot is a biomechanical marvel.  It is composed of 26 bones and 31 articulations or joints.  The bones and joints work together in concert to propel us through the earth’s gravitational field.  It is a dynamic structure that is constantly moving and changing with its environment, whether it is in or out of footwear.  Problems with the bones or joints of the foot, or the forces that pass through them, can interfere with this symbiosis and create problems which we call diagnoses.  They can range from bunions, plantar fasciitis, shin splints, TFL syndrome, abnormal patellar tracking, and lower back pain just to name a few.

Before we go any further, we should talk a little bit about gait (ie walking pattern). Normal walking can be divided into 2 phases, stance and swing. Stance is the time that your foot is in contact with the ground. This is when problems usually occur. Swing is the time the opposite, non weight bearing foot is in the air.

 

The bones of the foot go through a series of movements while we are in stance phase called pronation and supination. Pronation is when your arch collapses slightly, to make your foot more flexible and able to absorb irregularities in the ground; this is supposed to happen right after your heel hits the ground. As your foot pronates, the leg rotates inward, which causes your knee to rotate in, which causes your thigh to rotate in, which causes you spine to flex forward. Supination is when your foot reforms the arch and makes your foot a rigid lever, to help you propel yourself; This is supposed to happen when you are pushing off with your toes to move forward. It is at this time that the entire process reverses itself, and your leg, knee, and thigh rotate outward and your spine extends backward. When these movements don’t occur, or more often, occur too much, is when problems arise. This can be due to many reasons, such as lack of movement between your foot bones (subluxation), muscle tightness, injury, inflammation, and so on.

 

Many people overpronate. This means that their arch stays collapsed too long while in stance phase, and they remain pronated while trying to push off. As we discussed, during pronation the foot is a poor lever. This means you need to overwork to propel yourself forward. This can create arch pain, inflammation on the bottom of the foot (plantar fascitis), abnormal pressure on your foot bones (metatarsalgia), knee pain, hip pain and back pain.

 

Skiing is a stance phase sport. While skiing, your foot stays relatively immobile in a ski or snowboard boot (i.e. it is not moving through a gait cycle). A footbed is designed to create a level surface for your feet and keep them in a neutral posture. It accomplishes this by “bringing the ground up to your foot.” They are generally custom designed to an individuals foot through many different methods. They work incredibly well (as long as the foot remains in a static posture) and many people extol the benefits and improvements in their snow sports when using these.

 

Running, hiking and cycling are more dynamic. Sports like these demand a device that changes the biomechanics, so here an orthotic would be most appropriate.

 

Orthotics are always custom made devices. They actually improve the mechanics of your foot and make it function more efficiently by altering the shape and function of the arch as the foot moves through various activities. They act like a footbed but have the added benefit of functioning while dynamic (i.e. moving) as well. This works as well or better than a footbed, and is usable in other sporting activities, such as running, biking, hiking, skiing or snowbaording. Many people use their orthotic in their everyday shoes, to help prevent some of the problems and symptoms they are experiencing.

 

In summary, a footbed supports the foot in a neutral posture. It is great for activities where your foot is static or held in one position. An orthotic supports the foot in a neutral posture and improves the mechanical function of the foot. It can be used in static or dynamic activities. Remember to always consult with a professional who is well versed with the mechanics of the feet, ankles, knees, hips and back, since footbeds and orthotics have a profound effect on all these structures.

The Gait Guys. Bring you info you can use, each and every day.

All material copyright 2013 The Gait Guys/ The Homunculus Group. All rights reserved.

Podcast #30: Running your heart out ?

podcast link: 

http://thegaitguys.libsyn.com/podcast-30-running-your-heart-out

iTunes link:

https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138

Gait Guys online /download store:

http://store.payloadz.com/results/results.aspx?m=80204

other web based Gait Guys lectures:

www.onlinece.com   type in Dr. Waerlop or Dr. Allen  Biomechanics

Today’s show notes:

Neuroscience Piece:

1. Nanosponges could soak up deadly infections like MRSA from your bloodstream
http://www.theverge.com/2013/4/15/4225834/nanosponges-kill-deadly-bacteria-mrsa-clinical-trial

2. iPhone-controlled bionic hands allow father to hold daughter’s hand for first time since accident
http://9to5mac.com/2013/04/15/iphone-controlled-bionic-hands-allow-father-to-hold-daughters-hand-for-first-time-since-accident/

3. The science behind Obama’s BRAIN project.
http://blog.brainfacts.org/2013/04/the-science-behind-obamas-brain-project/#.UXQraILeb8g
4. Blog reader asks:
I’ve noticed that I’m developing some calluses - on the outside of my big toes. They don’t hurt normally but if I walk for awhile or run a few miles, those (I’m assuming) calluses really starts to ache. Any suggestions for what I can do to help with that?
5. FACEBOOK readers asks:
Hello, I am new to “The Gait Guys,” and was wondering if you have done any blogs about Morton’s Neuromas and bunion treatments. I’m looking for ways other than surgery to fix this ailment. I would love to be able to run and exercise again. Thank you.
Jared

6. What Cardiologists Tell Their Friends

http://shine.yahoo.com/healthy-living/cardiologists-tell-friends-134500478.html
“Go easy with the exercise”
http://www.ncbi.nlm.nih.gov/pubmed/22953596

Mo Med. 2012 Jul-Aug;109(4):312-21.

Cardiovascular damage resulting from chronic excessive endurance exercise.


7. Brisk Walking Equals Running for Heart Health: Study

http://www.medicinenet.com/script/main/art.asp?articlekey=168974
By Steven Reinberg

8. Shoes:

9. Runners Can Improve Health and Performance With Less Training, Study Shows

http://www.sciencedaily.com/releases/2012/05/120531102205.htm

10. A Lesson in Neurology from Jimi Hendrix

by ;luke barnes
letterstonature.wordpress.com/2007/11/30/a-lesson-in-neurology-from-jimi-hendrix

On the topic of endurance training.....

On the topic of endurance training (which we discussed on this weeks PODcast, forthcoming in the next day or so; we have both been extraordinarily busy in our clinics); if you are a well trained athlete (ie endurance junkie), how might this effect your running gait?

So, you run 103 miles with an elevation change of over 31,000 feet, how do you think you would fare? These folks were tested pre and 3 hours post race on a 22 foot long pressure walkway at about 7.5 miles per hour. Here’s how this group of 18 folks did:

  1. increased step frequency
  2. decreased “aerial” time
  3. no change in contact time
  4. decrease in downward displacement of the center of mass
  5. decrease in peak vertical ground reactive force
  6. increased vertical oscillation
  7. leg stiffness remained unchanged

So what does this tell us?

  • wow, that is a lot of vertical
  • holy smokes, that is really far
  • don’t know how I would do with a race like that
  • they are fatigued (1, 2, 6)
  • they are trying to attenuate impact forces (2, 3, 4, 5, 7)

The system is trying to adapt the best it can. If you were to do a standard hip screen test (like we spoke about here)  you would probably see increased horizontal drift due to proprioceptive fatigue. Remember that proprioception (our bodies ability to sense its position in space) makes the world go round. Proprioception is dependent on an intact visual system (see our post yesterday) , an intact vestibular system and muscle and joint mechanoreceptors functioning appropriately). We would add here that central nervous system fatigue (ie central processing both at the cord and in the cortex) would probably play a role as well.

The take home message? The human machine is a neuro mechanical marvel and much more complex than having the right shoe or the right running technique. Training often makes us more competent and efficient, but everything has it limits.

The Gait Guys. Making it real with each and every post.

all material copyright 2013 The Gait Guys/ The Homunculus Group

J Biomech. 2011 Apr 7;44(6):1104-7. doi: 10.1016/j.jbiomech.2011.01.028. Epub 2011 Feb 20.

Changes in running mechanics and spring-mass behavior induced by a mountain ultra-marathon race.

Source

Université de Lyon, F-42023 Saint-Etienne, France. jean.benoit.morin@univ-st-etienne.fr

Abstract

Changes in running mechanics and spring-mass behavior due to fatigue induced by a mountain ultra-marathon race (MUM, 166km, total positive and negative elevation of 9500m) were studied in 18 ultra-marathon runners. Mechanical measurements were undertaken pre- and 3h post-MUM at 12km h(-1) on a 7m long pressure walkway: contact (t©), aerial (t(a)) times, step frequency (f), and running velocity (v) were sampled and averaged over 5-8 steps. From these variables, spring-mass parameters of peak vertical ground reaction force (F(max)), vertical downward displacement of the center of mass (Δz), leg length change (ΔL), vertical (k(vert)) and leg (k(leg)) stiffness were computed. After the MUM, there was a significant increase in f (5.9±5.5%; P<0.001) associated with reduced t(a) (-18.5±17.4%; P<0.001) with no change in t©, and a significant decrease in both Δz and F(max) (-11.6±10.5 and -6.3±7.3%, respectively; P<0.001). k(vert) increased by 5.6±11.7% (P=0.053), and k(leg) remained unchanged. These results show that 3h post-MUM, subjects ran with a reduced vertical oscillation of their spring-mass system. This is consistent with (i) previous studies concerning muscular structure/function impairment in running and (ii) the hypothesis that these changes in the running pattern could be associated with lower overall impact (especially during the braking phase) supported by the locomotor system at each step, potentially leading to reduced pain during running.

Copyright © 2011 Elsevier Ltd. All rights reserved.

http://www.ncbi.nlm.nih.gov/pubmed/21342691

How we keep our head steady while we run.

Evolved to run: How we keep our noodle steady while we run.

Have you ever given thought to your head movements during running or walking ? Ever wonder why the world doesn’t seem to bound around as we move ? Wonder why things look different through your eyes when you yourself are running as compared to when you are watching the nauseating jerky video of someone wearing a camera on their head ?
Bryce Vickmark for The New York Times interviewed Dr. Lieberman of the Harvard Nature study…. here is a quote from that interview.
“We (Lieberman) realized that there were special features in the human neck that enable us to keep our heads still. That gives us an evolutionary advantage because it helps us avoid falls and injuries. And this seemed like evidence of natural selection in our ability to run, an important factor in how we became hunters rather than just foragers and got access to richer foods, which fueled the evolution of our big brains.”

__________________________________________________

Gait Guys say this….. “The ability to see clearly while moving / running / hunting is a well rooted primitive neurologic function in man. The visual-motor system (oculomotor system) is capable of assimilating the visual information and making calculations for the small head displacements that occur with movement via neural mechanisms that control three-dimensional head posture while coordinating three-dimensional eye orientation. The body’s movements as a whole (eye, head and body) are part of a coordinated series of sensory-motor events that are used to voluntarily reorient the axis of gaze between objects.  Body movements themselves can make a predictable contribution to gaze shifts and one study (link) has shown that single neurons (yes, one small neuron all by itself) can code motor commands to move the body as well as the head and eyes.  It is a finely tuned system, an amazing system.  One we rarely appreciate anymore since running during a hunt for food no longer occurs in urban America.  Of course this function is seamlessly tested everyday in athletes, unless of course you are a football or other impact sport athlete, and have accelerated your noggin one too many times.  Ask any aging boxer or ex-football player how their visual-motor system is doing ! (On a slight tangent since there is so much info in the media on concussive syndromes these days, here is support for those dropped endzone passes in the concussed wide receivers...LINK and. LINK)

NY Times link: for the Lieberman article.

We are The Gait Guys…….. running and hunting outside the box everyday, looking for answers.

Unstable shoes provide more activation of selected lower extremity muscles and increased postural sway WHILE STANDING. Does this really surprise us?
 &ldquo; &hellip;it was shown that standing in the unstable shoe increased activity of the flexor di…

Unstable shoes provide more activation of selected lower extremity muscles and increased postural sway WHILE STANDING. Does this really surprise us?

 “ …it was shown that standing in the unstable shoe increased activity of the flexor digitorum longus, peroneal (PR) and anterior compartment (AC) muscles of the lower leg. No activity differences for the larger soleus (SOL) were identified between the stable and unstable shoe conditions.”. In English that means the muscles on the front, back and outside of your lower leg.

It goes on to say “Postural sway was greater while standing in the unstable shoe compared to barefoot and the stable control shoe.” and “Postural sway while standing in the unstable MBT shoe also decreased over the 6-week accommodation period.” Postural sway is one way of measuring proprioception or body position awareness. 

The key words here are “WHILE STANDING”. It DOES NOT SAY WALKING. We have talked about rockered shoes in numerous previous posts and we have always maintained that in the right circumstances, it can be a good thing, but not necessarily something you should go do your grocery shopping or gym workout in.

Gait Posture. 2010 Jun;32(2):215-9. doi: 10.1016/j.gaitpost.2010.04.018. Epub
2010 May 23.

Standing in an unstable shoe increases postural sway and muscle activity of
selected smaller extrinsic foot muscles.

Landry SC, Nigg BM, Tecante KE.

Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, 2500
University Drive N.W., Calgary, Alberta, Canada T2N 1N4. scott.landry@acadiau.ca

Inactivity or the under-utilization of lower limb muscles can lead to strength
and functional deficits and potential injury. Traditional shoes with stability
and support features can overprotect the foot and potentially contribute to the
deterioration of the smaller extrinsic foot muscles. Healthy subjects (n=28)
stood in an unstable MBT (Masai Barefoot Technology) shoe during their work day
for a 6-week accommodation period. A two-way repeated measures ANOVA was used to 
determine (i) if unstable shoe wear increased electromyographic (EMG) activity of
selected extrinsic foot muscles and increased postural sway compared to standing 
barefoot and in a stable control shoe and (ii) if postural sway and muscle
activity across footwear conditions differed between a pre- and
post-accommodation testing visit. Using an EMG circumferential linear array, it
was shown that standing in the unstable shoe increased activity of the flexor
digitorum longus, peroneal (PR) and anterior compartment (AC) muscles of the
lower leg. No activity differences for the larger soleus (SOL) were identified
between the stable and unstable shoe conditions. Postural sway was greater while 
standing in the unstable shoe compared to barefoot and the stable control shoe.
These findings suggest that standing in the unstable MBT shoe effectively
activates selected extrinsic foot muscles and could have implications for
strengthening and conditioning these muscles. Postural sway while standing in the
unstable MBT shoe also decreased over the 6-week accommodation period.

Copyright 2010 Elsevier B.V. All rights reserved.

One simple hip screen that gives you lots of information.

This is the one leg standing test. We use it as a hip function (abduction) screen(as well as an exercise), to see if a person’s gluteus medius is working in a functional situation (as opposed to manual muscle testing).

As you may remember (don’t remember? Click here), the gluteus medius fires throughout stance phase (ie; when the foot is on the ground). It keeps the pelvis level while the foot is on the ground and works in conjunction with the opposite quadratus lumborum muscle (if you have not read up on this, please see our groundbreaking work on the problematic cross over gait, found here, here and here).

The test is simple; try it on yourself while watching yourself in a mirror. Stand on one leg on your foot tripod (the heel, base of big toe and base of little toe). Raise the opposite foot off the ground by flexing the thigh. Observe.

You should see the pelvis remaining level with no shift of the torso or hips. 

Watch for:

  • ·      Pelvic drift to the side you are standing on
  • ·      Pelvis drop on the side opposite you are standing on
  • ·      Body lean to the side you are standing on
  • ·      Excessive hiking of the opposite, non weight bearing hip
  • ·      Any combination of the above

 

Seeing any (or all) of these means the gluteus medius is probably having some trouble.  The reason we say probably is that a person with a hip problem (like arthritis) or an anatomically short leg may do some of these things in compensation.

The question you are hopefully asking is why do they drift, lean, hike, etc? Not everything you see is muscle weakness per se.

  • ·      Maybe they have a balance issue
  • ·      Maybe they have a disc injury
  • ·      Maybe they have injury to the nerve going to the gluteus medius
  • ·      Maybe they have a knee/ankle/foot issue
  • ·      And the list goes on…

So, if it were a muscle weakness, how could you fix it? Determine the cause. Begin at the bottom with foot exercises: tripod standing, lift/spead/reach with the toes etc. Then have them repeat the exercise IN A MIRROR, maintaining a level pelvis. Yes, it is that simple. Now see if they can translate that to their gait cycle. If so, great. If not, start again and repeat till they can.

The Gait Guys. Making it real, each and every day.

all material copyright 2013 The Gait Guys/ The Homunculus Group. All rights reserved. Please ask before using!

The Naked Foot: Thoughts for the Shoe Minimalist

Authors: Dr. Shawn Allen, Dr. Ivo Waerlop, Coach Chris Korfist

This may be one of the very first articles we ever wrote for The Gait Guys. It must be 7-8 years old now, before the barefoot-minimalist craze ever started. It is a bit dated, but we think that it was time to revisit its contents. You will see that many of our early core principles have not changed and you can see the thought process of where the fads and trends were projected to go.  Wind your mind back a near decade, and read on !

_____________________

If you want to follow the fad craze these days, just look to companies like Vibram and Nike. Vibram is the company that has brought you the soles and treads of many of the shoes you have worn over the years and of course Nike are the people who first brought you the “running shoe” as we know it today. Nike first brought us the waffle bottom trainer, the cross trainer, air pockets, “shocks” and, the Air Jordan and now their barefoot minimalist series, the Nike Free. Now, we are sure not many of you have heard of the “Vibram Five Fingers” barefoot slip-on ‘shoe’ but virtually everyone who runs in some manner has seen and heard about the Nike Free. What initially stymied us when they first came out was the obvious question of “Why would the same people who sell us the shoes, and give us so many varieties and categories to choose from, now be advocating that we train barefoot, or close to it? ” Or are they ?

  • (Addendum:  this article was originally written long ago, at the start of this fad, the fad that has become a trend.  The article traveled fast around the internet and garnered us much attention including a gig with Vibram as consultants.  But that was then, this is now.  We, and the trend have come a long way, and so has the research.  Some supportive for the trend, some disagreements and plenty of controversy.  The remainder of this article has been unedited, hence its tense and outdated verbiage, shoe types and research.  But we thought it was time to review before moving ahead.)

The Nike version they are pushing, first the Nike Free 5 and now down to the Nike Free 3, has a light weight thin flexible sole and thin vamp top cover material whoís purpose is to merely hold the shoe onto the foot. The Vibram device, which is a fascinating yet simple slipper, is even more simplistic but has some brilliance built right into its heart. It is merely a rubber sock with compartments for each individual toe but that is part of its brilliance. So why would Nike and now Vibram go against their own creations and advocate that we begin walking and running barefoot, or at least become more “shoe-minimalists” after decades of building shoe and sole lines that previously were designed for various conditions, foot types and activities ? There appears to be sound moral reasoning if you delve into the research, but you have to look closely and you have to be careful you do not have one of those foot types that could lead to problems with this type of footwear (but that is a topic for another article to come soon, see Part II).

Barefoot theories are nothing new. In 1960 Abebe Bikila, perhaps the greatest barefoot runner of all time, won the first of his consecutive gold medals without shoes setting a world record of 2:15:17. Englandís Bruce Tulloh was setting overseas records into the 1960’s running unshod, skin to the ground. Today Ken Bob Saxton is one of the most visible barefoot marathoners, long beard and all, and is an advocate of the technique.

With the introduction of the Nike Free, the interest in barefoot running resurfaced at the turn of the century. An article by Michael Warburton, published as an internet paper on barefoot theories, seemed to spark some of the resurgence of the method of running. In his brilliant paper he had some interesting thoughts and pointed out some noteworthy facts. He indicated that research showed that an extra mass of 100 grams attached to the foot diminished the economy of running by one percent. Thus, two 10 ounce shoes (the weight of a lightweight training shoe) could compoundingly cripple you by more than five percent in efficiency. In tangible terms that could be more than six minutes tacked onto a world class marathoner, taking a world record time to a mere first group finishing time. So, it is a question of weight and time, or is there something more ?

To get started with some hard and simple research facts, current research has been conducted showing that plantar (bottom of the foot) sensory feedback plays a central role in safe and effective locomotion, that more shoe cushioning can lead to higher impact forces on the joints and higher risk of injury, that unshod (without shoes) lowers contact time versus shod running, that there are higher braking and pushing impulses in shod versus unshod running, that unshod running presents a reduction of impact peak force that would reduce the high mechanical stress that occurs during repetitive running and that the unshod foot induces a neural-mechanical adaptation which could enhance the storage and restitution of elastic energy at ankle extensor level. These are only some of the research findings but they are some of the more significant ones. These issues will not only support injury management benefits for the unshod runner but increase speed, force and power output.

Stepping backwards in time a little, in the caveman days things were different. The foot was unshod (without shoes) from the moment of the first step until one’s dying day, and thus the foot developed and looked different. The sole of the foot was thicker and callused due to the constant contact with rough and offending surfaces thus preventing skin penetration, the foot proper was more muscular and it may have been wider in the forefoot and the toes were likely slightly separated due to the demands of gripping which would obviously necessitate increase muscular strength and bulk to the foot intrinsic muscles. It was the constant input of uneven and offending surfaces such as rocks, twigs, mud, foliage and debris that stimulated the bottom of the foot, and thus the intrinsic muscles, sensing joint positions and relaying those variations to the brain for corresponding descending motor changes and adaptations to maintain protection and balance. The foot simply worked different, it worked better, it worked more like the engineering marvel that it truly is. The foot was uncovered and the surfaces we walked on were uneven and challenging. However, as time went on, man decided to mess with a good thing. He took a foot that was highly sensitive, a virtual sensory organ with a significant sensory and motor representation in the brain (only the hands and face have more brain representation as represented by the sensory and motor homunculus of the brain) and he not only covered it up with a slab of leather or rubber but he then flattened and then paved not only his world, but also his home, with black hard top, cement, wood or tile thus completing the total sensory information deprivation of the entire foot. Thus, not only did he take away critical adaptive skills from himself and generations to follow, but he began the deprivation of the brain of critical information from which the central nervous system would need to develop and continue to function effectively. It is not unlikely that the man of pre-shod time had a strong competent foot arch (perhaps somewhat flat to increase surface area contact for adaptation), but one that did not need orthotics, stability shoes or rigid shanks and inserts. In other words, the foot and its lower limb muscles were strong with exceptional skills and endurance. But in today’s day and time things are now different. We now affix a shoe to the child’s foot even before he can walk and then when he does, all propriosensory information necessary for the development of critical spinal and central nervous system reflexes is ensured to be virtually absent. Is it any wonder why there are so many people in chronic pain from postural disorders related to central core weakness and inhibition ? Is it any wonder why so many people seem to have flat incompetent feet and arches? Man has done it to himself, but thankfully man has proven that what he can do, he can undo. Thankfully we see modern medical research that has delved into this realm of thought and has uncovered the woes of our ways and to follow, companies like those mentioned earlier are imagining and developing devices that will allow us some protection from modern day offenses such as glass, plastics and metal and thus allow us the slow and gradual return to our healthier foot days, all fashion sense aside.

 Shawn and Ivo, The Gait Guys

Two fellas that were here at the beginning, and two fellas that will be here for the duration. 

Podcast #29: DARPA Robots & Cartilage in Runners

podcast link: 

http://thegaitguys.libsyn.com/podcast-29-darpa-robots-cartilage-in-runners

iTunes link:

https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138

Gait Guys online /download store:

http://store.payloadz.com/results/results.aspx?m=80204

other web based Gait Guys lectures:

www.onlinece.com   type in Dr. Waerlop or Dr. Allen  Biomechanics


Today’s show notes:

1. Neuroscience Piece:
Human or Robot? Harder to Tell In Latest Bipedal Robot PETMAN Video
http://singularityhub.com/2013/04/07/human-or-robot-harder-to-tell-in-latest-bipedal-robot-petman-video/

Boston Dynamics is building the bipedal PETMAN (Protection Ensemble Test Mannequin) for the Defense Advanced Research Projects Agency (DARPA).

_____________
2.BIOWARE
How do we fit into this growing paradigm (bioware) and the bionics paradigm

_______
3.  http://www.sciencedaily.com/releases/2013/04/130408184727.htm

Human or Robot? Harder to Tell In Latest Bipedal Robot PETMAN Video

In their study published in the American Journal of Physiology: Regulatory, Integrative and Comparative Physiology on April 3, 2013, Roberts and Booth put rats in cages with running wheels and measured how much each rat willingly ran on their wheels during a six-day period. They then bred the top 26 runners with each other and bred the 26 rats that ran the least with each other. They repeated this process through 10 generations and found that the line of running rats chose to run 10 times more than the line of “lazy” rats.

4. Defending Barefoot

http://drnicksrunningblog.com/2013/04/04/experts-defend-barefoot-running-shoes-despite-new-evidence-indicating-the-footwear-could-promote-bone-injury/

5. hunter7979 asked you:

 Hey I have been injured for a long time I was hoping you could give me some insight on how to treat it. Started with ITBS in both knees about two years ago. Somehow my pelvis got thrown out of whack and I ended up with funky gait and scoliosis. I feel like my left leg is shorter, internally rotated and pronating. Supposedly my right leg is actually a tiny bit longer but not enough to make a real difference. Orthotics helped balance out my pelvis but I still walk/run funky. Appreciate it guys
6. Disclaimer

7.  How does your sport change your gait?
Twitter post we did….The Gait Guys (@TheGaitGuys)
4/4/13 1:18 PM
Doing lots of “in the guard” strategizing in jiujitsu last few weeks. Hip flexors are getting punished & inhibiting Glutes and hip extension.
8. Epidemic of Crocs footwear in the fort Meyers airport! No wonder we have so many gait problems. Would like to get @TheGaitGuys opinion!



A Scientific Look at Heeled Shoes. A nice follow up to the Zero Drop trend this week.

This blog post was from a year ago, but seems to be appropriate to follow up our two “zero drop” articles this week. Enjoy

http://well.blogs.nytimes.com/2012/01/25/scientists-look-at-the-dangers-of-high-heels/

Can you think of a better way to start the week than with a discussion of high heels? We all like high heels… Well, at least guys do (and we know quite a few women who do as well…some of you may be reading this post). NO, WE DO NOT LIKE TO WEAR THEM, but we can admire the way they make the calves look so great and the increased lumbar lordosis and accentuation of the greatest gait muscles ever created!

Were they based off “chopines” from the 15th century; an elevated shoe (7-30 inches high!) which kept the peoples feet literally “out of the muck” (they didn’t have modern plumbing back then) or are they older? Or was the heel invented out of necessity to keep horse riders literally “in the saddle” ? Chinese and Turkish history says maybe they were to keep women (particularly concubines) from escaping. For the intents of discussion, we will stick with this last premise, as it fits nicely with the findings of this article (based on the study published here)

Remember the neuromechanics posts on muscle spindles or golgi tendon organs (GTO’s) ? If not, click the links and check them out; suffice it to say that the take home message is: Spindles respond to length and GTO’s respond to tension.

We also remember that GTO;’s modulate the muscles function that they come from. In other words, they literally “turn off” the muscle they come from (it is a disynaptic, post synaptic pathway for you neuro geeks out there). In light of that, lets look at some quotes form the article:

“the scientists found that heel wearers moved with shorter, more forceful strides than the control group, their feet perpetually in a flexed, toes-pointed position. This movement pattern continued even when the women kicked off their heels and walked barefoot. “

No surprises here. Go up on your toes and take a few strides (more difficult for guys, since the biggest heel we may have is about 12mm in our running shoes). Which muscles are engaging? See how difficult it is to take a full stride? Try to engage your glutes. Not so easy, eh? Now put your foot flat on the floor, extend your toes and NOW engage your glutes. Easier? Presyanptic loading of the motor neuron pool pays big dividends!

They go on to say: “As a result, the fibers in their calf muscles had shortened and they put much greater mechanical strain on their calf muscles than the control group did.”

Hmmm… shortened muscles put under greater tension. Sounds like a job for the golgi’s, and what do they do? Inhibit the muscle from contracting. No wonder is was harder.

“In the control group, the women who rarely wore heels, walking primarily involved stretching and stressing their tendons, especially the Achilles tendon. But in the heel wearers, the walking mostly engaged their muscles.”

Wow, here is evidence They changed their motor programming!  Did you ever think that high heels could change the way our brain works? Maybe it’s a secret plot to take over the world….or maybe not…

The Gait Guys…Lovers of high heels as long as you don’t walk in them….

Zero Drop? Think before you drop. More to think about before you make the jump (or run, or walk or stand…)

Ramp Delta. Drop. Heel to toe differential. Stack height differential. You have likely heard all the words before. We are talking about the difference in height between the center of the heel and ball of the big toe on the foot. It is literally “how much heel” the shoe has. Some have upwards of 20mm, some none at all (zero drop). The average seems to be 10-15 mm for many shoes, but that tradition is evolving to less and less (Brooks for example now has the “Pure” Series with a 4 mm average and one shoe that can be either 4 or zero (The Drift)). New Balance has their miniumus, Altra has their army of shoes, Saucony has a variable selection. Everyone is on target with their collection of minimalist or minimalist-trending (or as we like to call them, “gateway”) shoes.

Since we are born “sans” shoes, zero seems “natural” or maybe the best, right? Maybe, maybe not. A lot depends on you and your anatomy however logic dictates that we were born with the rear and forefoot on the same plane so there has to be a natural logic to the zero drop trend. The problem remains, how long have you been forcing this non-natural state and how long (if at all) will you be able to return to the “less is more” trend?

If you have been in shoes with more drop your whole life, your musculoskeletal system and neurology has adapted to that. If we take away our favorite chair, pair of shoes, golf club or whatever, you may have something to say about it. Same for your feet. If you drop/lower your heel, there are biomechanical changes and possible consequences.

You may have read this weeks post, talking about having enough ankle range of motion available. Dropping the heel requires more dorsiflexion (or extension) of the ankle. If that range of motion is not available, then the motion needs to occur somewhere else.

So, where elsewhere in the body is the motion going to occur ? Dropping the ankle requires more knee extension. Do you have that range of motion available? Are your knees painful when you wear a zero drop shoe?

How about your hips? Dropping the heel requires more hip extension as well. This extension is often accompanied by internal rotation of the hip (ankle dorsiflexion, along with foot abduction and forefoot eversion are all components of pronation, which will cause medial rotation of the hip. Do you have this range of motion available, or do you have femoral retro torsion, and a zero drop shoe makes that worse?

What about the effect on the low back? Dropping the heel decreases the lumbar lordosis (the natural curve forward). Don’t believe us ? Just look at any woman in a 3 inch pump and you will see some lovely curves. This places additional stress on the posterior ligaments and joint capsules and compression and shear on the discs. Some spines won’t tolerate this, just like some won’t tolerate heels, which increases the lumbar lordosis and places more stress on the posterior joints.

What about the mid back? Dropping the heel decreases the thoracic curve. How much extension (backward movement) do you have in your mid back?

The same with the neck…and the list goes on….

As you can see, it is much more complex than just changing to a shoe with less drop. Because of the biomechanical changes and demands, it will probably cost you something, be it range of motion, comfort, function. We are not saying it isn’t worth it, or that you shouldn’t do it; we are saying go slow and listen to your body. What may be right for someone else may not be right for you … . either in the short or long term.

Earn your way. Don’t throw caution to the wind. We see people everyday that have suffered the above consequences due to listening to the wonderful marketing of the minimalist trend and from embracing some of the nonsense on the web.  We call these people, “patients”.  Don’t make yourself a patient, use your head when it comes to your feet.

The Gait Guys

Ivo and Shawn

All material copyright 2013 The Gait Guys/ The Homunculus Group. All rights reserved. Please ask before lifting our material.

Podcast #28: Nanotech, Athletes & Barefoot ?


podcast link: 

http://thegaitguys.libsyn.com/podcast-28-nanotechnology-athletes-minimalism

iTunes link:

https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138

Gait Guys online /download store:

http://store.payloadz.com/results/results.aspx?m=80204

other web based Gait Guys lectures:

www.onlinece.com   type in Dr. Waerlop or Dr. Allen  Biomechanics


Today’s show notes:

1. Neuroscience Pieces:

Technology is advancing so quickly that it won’t be long before the era of performance-enhancing drugs seems like the athletic Stone Age. Injecting or ingesting chemicals will be considered primitive when athletes will have the ability to have robotic cells powered by software coursing through their veins.

Russian Billionaire Wants to Create Cyborgs for Real

http://mashable.com/2013/04/01/avatar-project/


2.
Barefoot Running Can Cause Injuries, Too

By GRETCHEN REYNOLDS


http://well.blogs.nytimes.com/2013/03/06/barefoot-running-can-cause-injuries-too/
http://www.ncbi.nlm.nih.gov/pubmed/23439417

3. Running with sesamoiditis: How I resolved a 10 year injury by ditching my traditional running shoes. | Dr. Nick’s Running Blog
http://drnicksrunningblog.com/2013/04/04/running-with-sesamoiditis-how-i-resolved-a-10-year-injury-by-ditching-my-traditional-running-shoes/


4. Case
I have a question about peroneus longus in relation to “morton’s toe”. I did a very deep deep massage for an extended length of time and found that when I put my foot on the floor afterwards, the first metatarsal head was no longer raised!! Can you advise what may cause the peroneus longus to become tight, and if there any good stretches for it?
Thank you,Tracy



5. Do orthopedic shoes really help?
http://www.ncbi.nlm.nih.gov/pubmed/23496924

Well, they do seem to assist in foot placement and can enhance proprioception, so in the right circumstances, they can be an excellent adjunct to exercise and rehabilitation.

“Footwear adaptation led to pain relief and to improved foot & ankle proprioception. It is likely that that enhancement allows patients to better control foot placement. As a result, higher dynamic stability has been observed. LDS seems therefore a valuable index that could be used in early evaluation of footwear outcome in clinical settings.”


6. Shoes and Performance. Does it surprise you that it affects adolescents too? It shouldn’t:

http://www.sciencedaily.com/releases/2013/03/130319091420.htm

Midfoot strike in a non-zero drop shoe. Have you thought about this ?

Here is something to think about. As one midfoot strikes the foot during walking or running the individuals body mass is typically directly over the foot.  When this occurs in a zero drop shoe (ie. flat, your rear and forefoot are on the same plane) the tibia-ankle is at the very least, at 90 degrees. Meaning, the tibia is at the very least at 90 degrees and is at the very least perpendicular to the ground and plane that the foot is on.  And with just a little bit of forward body mass movement over the foot the critical and necessary range of 110-115 plus degrees of ankle dorsiflexion (depending on your reference source) is achieved. This means that one does not have to prostitute the foot into greater than normal pronation to drop the arch further to gain the extra amount of ankle rocker (dorsiflexion) that is necessary to pass over the foot.

However, think about this.  What if that same foot is in a stacked heel shoe.  There are plenty of shoes still out there that have a ramp delta that is above zero drop. So, what we have is a shoe that has the heel higher than the forefoot, a sloped shoe.  IF this same foot midfoot strikes what happens now ?

Well, midfoot strike now occurs in a relatively greater plantarflexed posture (ie. heel is raised higher than the forefoot because of the shoe). This means we are not anywhere near the 115 degrees necessary for normal gait, timely heel departure, timely forefoot load, timely hip extension, timely gluteal activation etc. These timely gait events are paramount to normal gait and when they are altered injury and altered tissue loads can occur.  Altered motor recruitment patterns are likely to ensue.  In the scenario proposed, as the body mass moves over the slightly plantarflexed foot we might now only get to 90 degrees of ankle rocker before the body mass is far enough forward to create the passive heel rise during late-midstance phase of gait. And when the body can only get 90 degrees of ankle dorsiflexion/rocker during midstance the extra amount of dorsiflexion range may need to come from some other joint.  It may come from more than normal midfoot pronation, knee hyperextension, knee valgus etc. This is potentially a long list of compensations.

Our point is simple here and at this time it is just a tip of the iceberg article for us.  But we thought we would put this idea out there to share some of the things we think about on a daily basis, and some of the things that get played out in our clinics each and every day. 

Changing your running form involves so much more than just changing your form. If you change to a midfoot or forefoot strike what kinds of biomechanics are you employing ? Do you have the neuromechanics to accompany these running form changes ? Do you have the necessary ranges of motion ? Do you have strength in potential compensation patterns to fend off both subtle and dramatic running form changes ?  If not, you might find out that your initial response is “ I just cannot do a midfoot or forefoot strike running form. I get foot pain, or knee pain, or hip pain.”

Conversely, think about this regarding our postulation above.  If you have been employing a midfoot strike or forefoot strike pattern in stacked heeled shoes and suddenly try a zero drop shoe you better be aware of symptoms such as pain, tightness or other complications.  Is your body able to adapt to a new (possibly increased) ankle-midfoot rocker or the demand of a greater ankle-midfoot with the newly dropped heel? Is your body immediately adaptive enough after going through that stage of gait with the heel higher than the forefoot for years ?  Just because you went to a running form clinic doesn’t mean  you are ready to make that your new form tomorrow. Change takes time, so be patient with your body and let it adapt.

Food for thought, especially for those who say to others. “Hey dude, chuck your ramped shoes and go minimialism or barefoot. Just go for it. I did and I was fine !”

What is fine for one, is not fine for all.

Shawn and Ivo

The Gait Guys

Another IFGEC Certification Granted

&ldquo;With more than 2 decades in the fitness industry, and a MS in Exercise Physiology, I&rsquo;ve learned that there is so little that I really know.  I am constantly looking to improve what I can do to help t…

Another IFGEC Certification Granted

“With more than 2 decades in the fitness industry, and a MS in Exercise Physiology, I’ve learned that there is so little that I really know.  I am constantly looking to improve what I can do to help the triathletes and runners that I see.   As an endurance coach and clinician that focuses on preventing injuries, optimizing performance, and avoiding reoccurring injuries, the IFGEC Shoe Fit Certification is going to be a keystone (much like the Navicular Bone) to my screening process of athletes and clients.  Making sure they are fitted properly in shoes, working with their movement patterns, teaching them running form skills, and then building on all aspects from there.  What I have learned from "The Gait Guys” has already made an impact on what I do, but it’s at a whole new level now.  This is not just a “online course”  this is real education that stays with you for life.  This is a true Ground Up approach to helping and is something that every running shoe store, coach, and medical professional that deals with runners and triathletes needs to learn.“
Ryan Smith, MS is owner of the Personal Impact, LLC and The Runners’ Clinic in the Cincinnati, Ohio area.  He is a USATF Level 1 Coach, Newton Natural Running Form Coach, & ACSM-CPT that works with runners and triathletes helping to prevent and recover from injuries that athletes deal with.  More information on Ryan Smith, visit his site at.  http://ryansmithfitness.com
Want to get certified or learn more? Email us at thegaitguy@gmail.com
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tumblr_mkhd6xIXbo1qhko2so2_1280.jpg

Do you think I need to replace my shoes?

These shoes appear to be well past their prime, to say the very least ! These poor dogs have the rear and forefoot varus “worn” right into them. You can see this represented particularly easily from the front, look at the lateral sloping of the shoe. It almost appears as if his foot could slide off the outside edge of the shoe. One can easily postulate that an inversion ankle sprain is just one unfortunate step away.

It looks like this medially posted shoe is not working for this fellow (you can see the medial post on the inner edge of the EVA midsole if you look carefully)  If you have questions on the “flare”?/post click here) . The client told us that they are “only a few years old” and planned on running one more ½ marathon in them this spring! Of course we mentioned they should put a office visit on the books the day after that race, because their ankles and knees were likely going to need it !

One can only imagine the lateral (genu varum) forces being placed on the knees, and who knows what kinds of increased shear forces are imparted into the menisci.  The lateral (inversion / varus) forces are going to impart a tendency of external rotation into the hips, and if one is busy externally rotating they are not going to internally rotate the hips when it is necessary to as the pelvis passes over the foot in midstance.  Additionally, an inverted /varus postured foot is more rigid because it is supinated which makes for a poor pronation/shock absorbing foot during the accomodative phase of the stance phase.

There are many more issues we could discuss here. But this was never meant to turn into a diatribe on specific biomechanical flaws, not this time at least.  Just remember this, whatever biomechanical flaws your feet have (and most of us have them) will eventually be pressed into the EVA foam of your shoes. Meaning, in time your shoes will reflect your aberrant flaws biomechanically.  And these newly built-into-the-shoe problems will now magnify the foot’s challenges and can accelerate pathology locally and globally.  Change your shoes often and as we have suggested in older blog posts, please consider having 2 shoes in your regular rotation.  One shoe being older and one being newer. We suggest starting an new shoe into the rotation once the old shoe has 200-250 miles and then alternating shoes every other day.  This way the foot is never seeing an older more deformed shoe for more than a day before getting some correction.  The point here, don’t let a shoe get 400-500 miles on it, in all its deformed glory, and then suddenly force the foot into a sudden biomechanical correction with a brand new shoe.  Abrupt changes lead to abrupt biomechanical demands on the system, so limit them and limit your risk for injury.

PS: Note the nice after-market “venting feature” in the right shoe near the little toe.

What some folks will try to do to save a few bucks…

Ivo and Shawn, The Gait Guys

Podcast #27: Futuristic Gait & Vertical Oscillations

 Pod #27

podcast link: 

http://thegaitguys.libsyn.com/pod-27-futuristic-gait-vertical-oscillations

iTunes link:

https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138

Gait Guys online /download store:

http://store.payloadz.com/results/results.aspx?m=80204

other web based Gait Guys lectures:

www.onlinece.com   type in Dr. Waerlop or Dr. Allen  Biomechanics


Today’s show notes:

1. Neuroscience Piece:

-http://www.designnews.com/author.asp?section_id=1386&itc=dn_analysis_element&doc_id=254901&page_number=1&dfpPParams=ind_182,industry_medical,aid_254901&dfpLayout=blog

Six months after doctors told him he would likely never walk again after a random accident at home, 49-year-old Chris Tagatac was back on his feet and taking steps, a feat that elated not only him, but also his family.

Tagatac didn’t accomplish this feat on his own, however. He was walking with the help of Ekso, a wearable robot from a company called Ekso Bionics that consists of braces, sensors, and motors that anticipate people’s movements and take steps for them.


2- NEURO 2
http://reuters.tumblr.com/post/46251254817/for-the-first-time-scientists-have-printed-human


For the first time scientists have printed human embryonic stem cells using a 3D printer

The Heriot-Watt University team’s research could eventually lead to human organs being printed on demand and an end to animal drug testing. Jim Drury reports.

 

3. Vertical Oscilations, Danny Abshire and Running & Walking

https://www.facebook.com/photo.php?v=575995729092248&set=vb.111772995514526&type=2&theater

This study’s findings findings clearly demonstrate that human walkers consume substantially more metabolic energy when they minimize vertical motion.

Anyhow, the summary of this peer reviewed article by Ortega concluded that :

“in flat-trajectory walking, subjects reduced center of mass vertical displacement by an average of 69% but consumed approximately twice as much metabolic energy over a range of speeds . In flat-trajectory walking, passive pendulum-like mechanical energy exchange provided only a small portion of the energy required to accelerate the center of mass because gravitational potential energy fluctuated minimally. Thus, despite the smaller vertical movements in flat-trajectory walking, the net external mechanical work needed to move the center of mass was similar in both types of walking. Subjects walked with more flexed stance limbs in flat-trajectory walking, and the resultant increase in stance limb force generation likely helped cause the doubling in metabolic cost compared with normal walking. Regardless of the cause, these findings clearly demonstrate that human walkers consume substantially more metabolic energy when they minimize vertical motion.”

J Appl Physiol. 2005 Dec;99(6):2099-107. Epub 2005 Jul 28. Minimizing center of mass vertical movement increases metabolic cost in walking. Ortega JD, Farley CT. Source



J Sports Sci. 2005 Jul;23(7):757-64.

Effect of a global alteration of running technique on kinematics and economy.



J Biomech. 2011 Apr 7;44(6):1104-7. doi: 10.1016/j.jbiomech.2011.01.
028. Epub 2011 Feb 20.

Changes in running mechanics and spring-mass behavior induced by a mountain ultra-marathon race.


http://www.technologyreview.com/view/413593/revealing-the-secrets-of-human-gait/

Revealing the secrets of human gait

A simple measure of the forces involved in walking may help diagnose and treat injuries and arthritis

So the work of Yifang Fan and pals at Jinan University in China is a refreshing step forward (so to speak). Fan and co say they have discovered an independent measure of gait which they call the vertical gait reaction force. This is a measure of the amount by which a person’s centre of gravity raises during two complete steps (with the left and then the right foot).

In healthy adults, and Fan and co have tested 173, this force is symmetrical with regard to left and right foot, a finding they call the principle of least action (in other words, the body does no more than it has to move you around). That’s useful, they say, because no other measure gives this kind of symmetric signal for all healthy people.

In adults carrying an ankle injury or with arthritis, the pattern of force is not symmetrical. That allows a quick diagnosis simply by measuring this force and may in future point to the type of rehabilitation that may treat the condition.

_____________
4. Shoe: NB minimus (the new one) and the HI-REZ

http://www.newbalance.com/Minimus-Hi-Rez-Where-Science-Meets-Design/article_minimus_hirez_where_science_meets_design,default,pg.html___________________

 Shawn and Ivo, The Gait Guys

 

More on the Great Debate: Does decreased step height (resulting in less vertical oscillation) increase running economy

There continues to be a plethora of conflicting data out there on the web. Yes, shocking realization !

This study looks at 16 triathletes; 8 folks trained in the “pose method” of running for 12 weeks, versus the 8 folks who just kept running in their usual fashion (ie. the control group perhaps also known as the “beer and Doritos group"  : )  ). They measured changes in stride length (decreased in posers), vertical oscillation (decreased in posers) and oxygen cost (increased in posers).

According to the study’s conclusion

"The global change in running mechanics associated with 12 weeks of instruction in the pose method resulted in a decrease in stride length, a reduced vertical oscillation in comparison with the control group and a decrease of running economy in triathletes”

Why the changes? Perhaps it takes longer to train appropriately in this method and to become efficient at the method. Perhaps when you lose the “pendulum effect” we spoke about last Thursday on the blog, you become less efficient, or maybe there is another factor. MAYBE “pose running” just isn’t more efficient. Time and more studies will tell.

The Gait Guys. Telling it like it is and bringing you the meat….without the filler

all material copyright 2013 The Gait Guys/ The Homunculus Group. Please ask before lifting our stuff.

J Sports Sci. 2005 Jul;23(7):757-64.

Effect of a global alteration of running technique on kinematics and economy.

Source

Department of Exercise Science, Health Promotion and Recreation, Colorado State University - Pueblo, Pueblo, CO, USA. george.dallam@colostate-pueblo.edu

Abstract

In this study, we examined the consequences of a global alteration in running technique on running kinematics and running economy in triathletes. Sixteen sub-elite triathletes were pre and post tested for running economy and running kinematics at 215 and 250 m.min-1. The members of the treatment group (n=8) were exposed to 12 weeks of instruction in the “pose method” of running, while the members of the control group (n=8) maintained their usual running technique. After the treatment period, the experimental group demonstrated a significant decrease in mean stride length (from 137.25+/-7.63 cm to 129.19+/-7.43 cm; P<0.05), a post-treatment difference in vertical oscillation compared with the control group (6.92+/-1.00 vs. 8.44+/-1.00 cm; P<0.05) and a mean increase in submaximal absolute oxygen cost (from 3.28+/-0.36 l.min-1 to 3.53+/-0.43 l.min-1; P<0.01). The control group exhibited no significant changes in either running kinematics or oxygen cost. The global change in running mechanics associated with 12 weeks of instruction in the pose method resulted in a decrease in stride length, a reduced vertical oscillation in comparison with the control group and a decrease of running economy in triathletes.

PMID:16195026 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/pubmed/16195026