Welcome to Monday folks and news you can use! Have a patient with weak hip abductors? Here is another great closed chain gluteus medius/ Maximus/minimums exercise we utilize all the time called “"hip helicopters” Try it in yourself, then try it on your patients and clients, then teach others : )

Pod #100: Hill Running + Cortical Brain Changes in Injuries

Pod #100  Hill Running + Cortical Brain Brain Changes in Injuries, Plus leg length challenges, Sole vs Heel lifts, Varying your Running Surface, Frontal plane biomechanics, Baker Cyst and Popliteal Muscle problems and more !

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Other Gait Guys stuff

A. Podcast links:

direct download URL: http://traffic.libsyn.com/thegaitguys/pod_100f.mp3

permalink URL: http://thegaitguys.libsyn.com/podcast-100-hill-running-cortical-brain-brain-changes-in-injuries

B. iTunes link:
C. Gait Guys online /download store (National Shoe Fit Certification & more !)
D. other web based Gait Guys lectures:
Monthly lectures at : www.onlinece.com type in Dr. Waerlop or Dr. Allen, ”Biomechanics”

-Our Book: Pedographs and Gait Analysis and Clinical Case Studies
Electronic copies available here:


-Barnes and Noble / Nook Reader:


-Hardcopy available from our publisher:

Show Notes:

1 Cortical change in chronic low back pain

-Chronic low back pain is characterised by a range of structural, functional and neurochemical changes within the brain. Functional changes in individuals with chronic low back pain are reflected in a cortical reorganization, altered cortical activity and altered cortical responsiveness.

2  Lifting weights can change the brain

3  Importance of varying running surfaces

4  Emergence of postural patterns as a function of vision and translation frequency.
J Neurophysiol. 1999 May;81(5):2325-39.
Our results suggest that visual information was important to maintaining a fixed position of the head and trunk in space, whereas proprioceptive information was sufficient to produce stable coordinative patterns between the support surface and legs.     *The CNS organizes postural patterns in this balance task as a function of available sensory information, biomechanical constraints, and translation frequency.

5  Previous hamstring injury is associated with altered kinematics.
“Previously injured athletes demonstrated significantly reduced biceps femoris muscle activation ratios with respect to ipsilateral gluteus maximus, ipsilateral erector spinae, ipsilateral external oblique, and contralateral rectus femoris in the late swing phase. We also detected sagittal asymmetry in hip flexion, pelvic tilt, and medial rotation of the knee effectively putting the hamstrings in a lengthened position just before heel strike.”

The biomechanics of running in athletes with previous hamstring injury: A case-control study. C. Daly1, U. McCarthy Persson2, R. Twycross-Lewis1, R. C. Woledge1,† andD. Morrissey1,

Have a patient with weak hip abductors? Here is a great closed chain gluteus medius exercise called “"hip airplanes” we utilize all the time. Try it in yourself, then try it on your patients and clients, then teach others : )

Starting and stopping your gait. How we do it gracefully.

Can you imagine being unable to stop moving graciously? Imagine that every attempt to halt your walking or running was like smacking into a wall or stumbling to a halt ? Kind of like that amateur driver who uses no grace or finesse, every start is a stomp on the gas and every stop is a slamming on the brakes.  Or can you imaging suffering from FOG (freezing of gait) as in some Parkinson’s patients ?  
When we are healthy, we take locomotion for granted. When we are in pain, movement can become labored and challenging; when we have a neurologic disease to the locomotor centers, we can find it almost impossible.  On occasion, it can be the seemingly simplest of things that can cause the greatest of difficulties, for example, we take stopping for granted and we underestimate the complexity of initiating movement. It is one of those things in life, you do not know what you have until you lose it.  When was the last time you even thought about starting or stopping your movements ? It is so natural that the thought doesn’t even reach the surface of our conscious thought.  When was the last time you walked towards your kitchen sink to wash the dishes and you consciously thought, 

“ok, we are about 3 more steps from the sink, you had better slow down … . ok, 2 more steps … 1 more step, this is the last one … .  ok, that is it, you have arrived at the sink, both feet stop moving … . . initiate double stance support, 50% weight on both feet… . .  begin standing mode.”

There is a brainstem pathway specifically dedicated to control locomotor arrest. Activating this pathway stops locomotion, while inhibiting the pathway enables locomotion.

In the study below, researchers Julien Bouvier and Vittorio Caggiano together with Professor Ole Kiehn and colleagues studied how the complex brainstem neuronal circuits control locomotion in mice.  What they found was this, 

Neuronal populations in the Reticular Formation of the brain “constitute a major excitatory pathway to locomotor areas of the ventral spinal cord. Selective activation of these neurons (V2a) of the rostral medulla stops ongoing locomotor activity, owing to an inhibition of premotor locomotor networks in the spinal cord. Moreover, inactivation of such neurons decreases spontaneous stopping in vivo. Therefore, the V2a “stop neurons” represent a glutamatergic descending pathway that favors immobility and may thus help control the episodic nature of locomotion.”-Bouvier et al.

Human locomotion is an extremely complex task. It is one that requires all sensory and motor pathways to be intact and reflexive controls such as central pattern generators to function properly.  Gait is a complex task that requires synchrony, rhythmicity, balance, coordination, endurance and strength to name a few.  Initiating gait is highly complex, as is arresting one’s gait.  We take for granted how complex these task are at coordinating muscles, joints, limbs, vision, proprioception, vestibular inputs and many other components not to forget the cerebral connection bring it all together to get us from one place to the next is a safe fashion. It is only when things go wrong that we realize how fragile, and how complex, the system truly is.  Don’t believe us ?  Well then, try to over ride the system next time you are coming to a curb at the corner of the busiest street in your town.  Try to over ride the coordinated stop mechanism that enables you to suddenly stop perched on the curb, observing oncoming traffic, standing safely without falling into the lane.

Shawn Allen, one of The Gait Guys

“Descending command neurons in the brainstem that halt locomotion” by Julien Bouvier, Vittorio Caggiano, Roberto Leiras, Vanessa Caldeira, Carmelo Bellardita, Kira Balueva, Andrea Fuchs, and Ole Kiehn in Cell. Published online November 19 2015 doi:10.1016/j.cell.2015.10.074

This brief blog post was inspired from this article on the same topic. http://neurosciencenews.com/v2a-neurons-locomotion-neuroscience-3119/

Achilles tendonitis: Lift the heel, right? It does not appear so.

There was a recent article in one of our favorite journals, Lower Extremity Review which reviewed and expanded upon another study from Medicine and Science in Sports and Exercise titled “Running shoes increase achilles tendon load in walking: an acoustic propagation study.” We discussed some perspectives of this topic in one of our recent podcasts.
The article discusses a new technique (1,2) for looking at tensile loads in the achilles and looks at 12 symptom free individuals on a treadmill barefoot and in a shoe with a 10 mm drop (heel is 10mm higher than the forefoot) and found:

“Footwear resulted in a significant increase in step length, stance duration, and peak vertical ground reaction force compared with barefoot walking. Peak acoustic velocity in the Achilles tendon (P1, P2) was significantly higher with running shoes.”(1)

According to LER: “The researchers also found changes in basic gait parameters associated with walking in running shoes versus barefoot, which the author Wearing said may help explain the increased tendon load with shoes. Shoes increased mean ankle plantar flexion by 4° during quiet stance as measured by electrogoniometry. When walking with shoes, participants adopted a lower step frequency but greater step length, period of double support, peak vertical ground reaction force, and loading rate than when walking barefoot. The researchers also noted that participants’ stance phase was relatively longer (4%) during shod walking than during barefoot walking.” (3)

Of course, our big question is why?

Why would an increase in step length result in increased tension?

Perhaps, as the force that the heel would hit the ground would be increased because of a longer acceleration time (F=ma), and it so happens this is what they found. The friction of the heel striking the ground would accelerate anterior translation of the talus, which plantar flexes, everts and abducts, accelerating pronation. The medial gastroc would be called into play to slow calcaneal eversion and this would indeed increase achilles tension.

Or perhaps it’s the fact that

the foot will strike in slight greater plantarflexion

(at least 4 degrees according to the study) and this results in an immediate greater load to the Achilles tendon.  Go ahead and try this while walking even if you’re barefoot. Walk across the floor and strike more on your forefoot. You will notice that you have an increased load in the tricep surae group.

Does this slight plantarflexion of the ankle contribute to greater eccentric load during stance phase?

This would certainly activate 1a afferent muscle spindles which would increase tensile stresses in the achilles tendon.

This seems to fly directly in the face of the findings of Sinclair (4) who investigated knee and ankle loading in barefoot and barefoot inspired footwear and found increased achilles loading in both compared to “conventional shoes”.

Of course this also begs the question of what type of shoes were they wearing? High top or low top shoes and were the shoes tied or not? High top shoes seem to reduce Achilles tension more so than low top shoes, especially if they are tied (5).

Whatever the reason, this questions the use of putting a lift or a higher heeled shoe underneath the foot of people that have Achilles tendinitis.  Once again what seemed to make biomechanical sense is trumped by science.

We think training people to have greater amounts of hip extension as well as ankle dorsiflexion,  as well as appropriate foot and lower extremity biomechanics with the requisite  skill, endurance and strength is a much better way to treat Achilles tendonitis regardless of whether they’re wearing footwear or not.

Dr. Ivo Waerlop, one of The Gait Guys


1. Wearing SC, Reed LF, Hooper SL, et al. Running shoes increase Achilles tendon load in walking: An acoustic propagation study. Med Sci Sports Exerc 2014;46(8):1604-1609.  http://www.ncbi.nlm.nih.gov/pubmed/24500535
2. Reed LF, Urry SR, Wearing SC. Reliability of spatiotemporal and kinetic gait parameters determined by a new instrumented treadmill system. BMC Musculoskelet Disord 2013;14:249.
3. Black, Hank. Achilles oddity: Heeled shoes may boost load during gait. In the Moment:Rehabilitation   LER Sept 2014  http://lermagazine.com/news/in-the-moment-rehabilitation/achilles-oddity-heeled-shoes-may-boost-load-during-gait
4. Sinclair J. Effects of barefoot and barefoot inspired footwear on knee and ankle loading during running. Clin Biomech (Bristol, Avon). 2014 Apr;29(4):395-9. doi: 10.1016/j.clinbiomech.2014.02.004. Epub 2014 Feb 23.
5. Rowson S1, McNally C, Duma SM. Can footwear affect achilles tendon loading? Clin J Sport Med. 2010 Sep;20(5):344-9. doi: 10.1097/JSM.0b013e3181ed7e50.

Now THERE”S some internal tibial torsion!

So, this gent came in to see us with L sided knee pain after it collapsed with an audible “pop” during a baseball game. He has +1/+2 laxity in his ACL on that side. He has subpatellar and joint line pain on full flexion, which is limited slightly to 130 (compared to 145 right)

 We know he has internal torsion because a line drawn from the tibial tuberosity dropped inferiorly does not pass through or near the plane of the 2nd metatarsal (more on tibial torsions here)

What would you do? Here’s what we did:

  • acupuncture to reduce swelling
  • took him out of his motion control shoes (which pitch him further outside the saggital plane)
  • gave him propriosensory exercises (1 leg balance: eyes open/ eyes closed; 1 legged mini squats, BOSU ball standing: eyes open/eyes closed)
  • potty squats in a pain free range
  • ice prn
  • asked him to avoid full flexion

Is it any wonder he injured his knee? Imagine placing the FOOT in the saggital plane, which places the knee FAR outside it; now load the joint an twist, OUCH!

Podcast #99: How foot placement, the glutes and cross over gait all come together and make sense.

Topics: Plus, How foot placement, the glutes and cross over gait all come together and make sense. Plus, discussions on vibration,proprioception, cerebellum and movement.

Show Sponsors:



A. Link to our server: http://traffic.libsyn.com/thegaitguys/pod_99final.mp3

Podcast Direct Download: http://thegaitguys.libsyn.com/podcast-99-how-foot-placement-the-glutes-and-cross-over-gait-all-come-together-and-make-sense

Other Gait Guys stuff

B. iTunes link:
C. Gait Guys online /download store (National Shoe Fit Certification & more !)
D. other web based Gait Guys lectures:
Monthly lectures at : www.onlinece.com type in Dr. Waerlop or Dr. Allen, ”Biomechanics”

-Our Book: Pedographs and Gait Analysis and Clinical Case Studies
Electronic copies available here:


-Barnes and Noble / Nook Reader:


-Hardcopy available from our publisher:

Show notes:

Evaluating the Differential Electrophysiological Effects of the Focal Vibrator on the Tendon and Muscle Belly in Healthy People ARTICLE in ANNALS OF REHABILITATION MEDICINE · AUGUST 2014 DOI: 10.5535/arm.2014.38.4.494 · Source: PubMed

J Neurophysiol. 2014 Jul 15;112(2):374-83. doi: 10.1152/jn.00138.2014. Epub 2014 Apr 30. A neuromechanical strategy for mediolateral foot placement in walking humans.  Rankin BL

J Neurophysiol. 2015 Oct;114(4):2220-9. doi: 10.1152/jn.00551.2015. Epub 2015 Aug 19.

Hip proprioceptive feedback influences the control of mediolateral stability during human walking.

Roden-Reynolds DC1, Walker MH1, Wasserman CR1, Dean JC2.

Eur Spine J. 2015 May 26. [Epub ahead of print]
Prevalence of gluteus medius weakness in people with chronic low back pain compared to healthy controls.
Cooper NA1, Scavo KM, Strickland KJ, Tipayamongkol N, Nicholson JD, Bewyer DC, Sluka KA.

Prog Brain Res. 2004;143:353-66. Role of the cerebellum in the control and adaptation of gait in health and disease. Thach WT1, Bastian AJ.

You’d have to be smart to walk this lazy, and people are

Research suggests that humans are wired for laziness


Jessica C. Selinger, Shawn M. O’Connor, Jeremy D. Wong, J. Maxwell Donelan. Humans Can Continuously Optimize Energetic Cost during Walking. Current Biology, 2015; DOI: 10.1016/j.cub.2015.08.016

The “Dodgy Foot”, a UK runner’s dilemma.

We get “help me” emails from all over the world on a regular basis. Recently we received this photo from a runner in Oxford, UK,  The runner was frustrated, explaining a “dodgy foot”.  We like the word. 

dodg·y    däjē/

-dishonest or unreliable; potentially dangerous; of low quality.

We can guarantee you that the solution here to this runner’s form issue is not wholly at the foot which appears “in toed” and slanted and appears ready to kick the back of the right heel, not to mention the knees that are about to brush together.  Thus, merely working on their foot strike would be so remedial and corrupt that it would a crime. 

Ivo and I do not take on cases via the internet because we cannot give all the information because we cannot examine the client, many do offer such services but people are not being given the whole story and we pledged long ago not to be part of the problem.  Anyone who recommends exercises from things they see on a video gait analysis are basically doing the same disservice in our opinion. But sometimes, as in this case, their inquiry is simple, there is a photo or video and it allows us to highlight an important component of an individuals gait which can lead them on a road to appropriate discovery. This is one of those cases.  I will not be presenting a solution, because I do not have the examination information I need, but I will propose a solid thought process that further investigation may afford progress towards resolution.

This is a non-pathologic cross over gait in my mind until proven otherwise, there may be other sources, causes and components, but when it quacks like a duck you’d be silly not to check for webbed feet. This runner even confirmed upon questioning that the left foot scuffs the inside of the right ankle/shin often, both sides scuff in fact but more left shoe on right shin. No Einsteinian epiphany there. 

  • This means a narrow swing through  (adducting) left limb. 
  • This means stance and swing phase gluteus medius communication problems. 
  • This means swing leg foot targeting problems. 
  • This often suggests right, but sometimes both right and left, frontal plane pelvis sway problems which means pelvis control is challenged which means core lumbar stability control is challenged. 
  • This means adaptive arm swing changes from the clean norm.  
  • This does NOT mean this runner has pain, or pain yet, or maybe never will have pain but there are many determinants of that which I will discuss below. 

But, make no mistake, this is flawed gait mechanics. The left swing leg is clearly targeting a more medial placement, meaning limb adduction (active or passive or both is to be determined) and this is a product of the cross over gait (unfamiliar with the cross over gait ? SEARCH our blog for the term, you will need a few hours of free time to get through it all).  Some would call the cross over gait a lazy gait, but I would rather term it an efficient gait taken too far that it has now become a liability, a liability in which they can no longer stabilize frontal plane sway/drift. A wider gait on the other hand, as in most sprinters, is less efficient but may procure more power and the wider base is more stable affording less frontal plane drift. Just go walk around your home and move from a very narrow line walking gait to a wide gait and you will feel a more powerful engagement of the glutes. Mind you, this is not a fix for cross over gaits, gosh, if it was only that simple !

This runner must investigate whether there is right frontal plane drift, and if it is in fact occurring, find the source of the drift.  It can come from many places on either limb. (This client says they are scuffing both inside ankles, which is not atypical and so we likely have drift on both right and left). We have discussed many of them here in various places on the blog over the years. Now as for “Why” the foot looks in toed, well that can also come from many places. Quite simply the adducted limb once it leaves toe off can look like this. But, perhaps it is also a product of insufficient external rotation maintenance occurred during that left stance phase, affording more internal rotation which is being unchecked and observed here during early swing.  Remember though, if this is in fact a cross over gait result, in this gait the limb approaches the ground unstacked (foot is too far inside a left hip joint plumb line) the foot will greet the ground at a far lateral strike and in supination.  Pronation will thus be magnified and accelerated, if there is enough time before toe off. However, and you can try this on your own by walking around your home, put yourself in terminal stance at toe off. Make sure you have the foot inverted so you are toeing off the lateral toes (low gear toe off). Does this foot not look like the one in the photo ? Yes it does, now just lift the foot off the ground and you have reproduced this photo. And when combined with a right pelvis drift, the foot will sneak further medially appearing postured behind the right foot. 

Keep this in mind as well, final pronation and efficient hallux (big toe) toe off does often not occur in someone who strikes the ground on a far lateral foot. I am sure this runner will now be aware of how poorly they toe off of the big toe, the hallux.  They will tend to progress towards low gear toe off, off the lesser toes. This leaves the foot inverted and this is what you are seeing in her the photo above. That is a foot that is inverted and supinated and it carried through all the way through toe off and into early swing. It is a frequently component of the cross over gait, look for it, you will find it, often. 

Final thoughts, certainly this can be an isolated left swing phase gluteus medius weakness enabling an adducted swing limb thus procuring a faulty medial foot placement, but it is still part of the cross over phenomenon.  Most things when it comes to a linked human frame do not work in isolation.  But i will leave you with a complicating factor and hopefully you will realize that gait analysis truly does require a physical exam, and without it you could be missing the big picture problem.  What if she has a notable fixed anatomic internal tibia torsion on that left side. Yup, it could all be that simple, and that is not something you can fix, you learn to manage that one as a runner.  

* Side bar rant: Look at any google search of runners photos and you will see this type of swing limb foot posturing often, far too often.  And yes, you can take the stance that “I do it as well and i have no injuries or problems so what is the big deal?”.  Our response is often “you do have an issue, it may be anatomic or functional, but you do have an asymmetrical gait and you think it is not a problem, YET”. And maybe you will run till you are 6 feet under and not have a problem because you have accomodated over many years and you are a great compensator, yes, some people get lucky. Some people also do not run enough miles that these issues express themselves clinically so lets be fair. But some of these people are reality deniers and spend their life buying the newest brace or gadget, trying a different shoe insert, orthotic or new shoe of the month and shop over and over again for another video gait analysis expert who can actually fix their pain or problem. And then there are those who have a 45 minute home exercise program that they need to do to keep their problems at bay, managing, not fixing anything.  Or, they spend an hour a week on the web reading article after article on what are the top 4 exercises for iliotibial band syndrome for example. They shop for the newest Graston practitioner, the newest kinesio taping pattern, Voodoo bands, breathing patterns, compression socks etc.  And sometimes they are the ones that say they still dont have a problem.You get the drift.  Gosh darn it, find someone who knows what the hell they are doing and can help you fix the issues that are causing the problem.  And yes, some of the above accoutrements may be assistive in that journey. 

I have dealt with this unique toe off issue way too many times not to roll my eyes at it any longer. It is to the point that it is an automated evaluation and solution program that begins to run in my head. Once you see something enough times, you learn all of the variations and subtle nuiances that a problem can take on. But, trying to fit everyone into a similar solution model is where the novice coach, trainer or clinician will get into trouble. Trust us, it all starts with an examination, a true clinical physical examination.  If one leaves the investigatory process to a series of screens or functional movement patterns, “activation” attempts, digital gait analysis or strength tests one is juggling chainsaws and the outcome you want is often not likely to occur. There is nothing wrong with making these components part of the investigation process, but on their own, they are not enough to get the honest answer many times.  Of course, Ivo and i were not able to jump the pond and examine this runner with our own eyes and hands so today’s dialogue was merely to offer this runner some food for thought to open their mind to our thought process, in the hopes that they can find someone to help them solve the underlying problem and not merely make the gait look cleaner. Making someone’s walking or running gait look cleaner is not hard, but making it subconsciously competent and clean (without thought or effort) requires a fix to the underlying problem. We can ALMOST guarantee you that the solution here to this runner’s form issue is not wholly at the foot that looks in toed and slanted. Merely working on their foot strike would be so remedial and corrupt that it would a crime.

Dr. Shawn Allen, one of the gait guys

Look at your patients and clients shoes!

Can you see the varus cant to the heel counter of these shoes? This is an Asics  Gel  Kayano; a shoe we seem to see manufacturers defects in frequently. This could be a good thing for an overpronator, but could be a bad thing for a supinator. With a drop ( ramp delta) of 13 mm, and a narrow toe box, we are not huge fans…

Ivo and i have a bunch of screens we use to glean information as we move down through the examination tree. Here is one i like to use, it is quick and easy and allows you to check something functionally and quickly while a client turns over. It is a very VERY small piece of a larger puzzle, but it is knowing what to look for and then what to test to verify. You might not have noticed this clients limitations in a passive supine joint assessment, but often when you load them up, mobility and stability challenges start to blossom into something different. If you are thinking, “possible loss of right knee flexion or left hip flexion” you are on the right track, with *caveat. There is more to it, but it is a start.  Hope to see you on www.onlinece.com next week for our new course, “thinking through functional pathologic biomechanics”.  
* Caveat: The lack of joint flexion range doesn’t necessarily mean they need more flexion, it means their flexion mobility is lost and that might mean they need more stability there or elsewhere for the flexion to present. This is the challenge a screen provides, it doesn’t tell you what’s wrong, it tells you if they can or cannot do the screen. If they cannot, it’s your job to find out why, but giving this particular client flexion work (range or strength work) would have led to a quick demise in their status. Quite often a joint displaying less mobility displays such because it has insufficient stability (from lack of skill, endurance, strength, proprioceptive etc) , but this is not a hard and firm rule. It’s your commission to find out the functional limitation(s) that are leading to these deficits and challenges.