More on landing mechanics.
Here is a recent article on landing mechanics. This article talks about the landing mechanics far past where I feel the first stage of vulnerability is, which is initial forefoot load, as i discuss in the video pertaining to landing from a jump or if sprinting (forefoot loading). IF landing occurs in low gear (lateral half of the forefoot), inversion risks are higher.
The medial foot tripod, high gear toe off (1st and 2nd mets) is where we should be taking off from, and landing initially upon. Anything lateral is vulnerable without the lateral column strength (lateral gastrocsoleus complex, peronei longus/brevis).
This article talks about knee flexion angles and ACL vulnerability, far after this initial loading response. The article some valid conclusions in that phase.

– Dr. Shawn Allen

Posture specific strength and landing mechanics.

http://lermagazine.com/article/posture-specific-strength-and-landing-mechanics

https://www.youtube.com/watch?v=8T9UzOaYxmo

Ankle sprains and the reorganization of the sensorimotor system

“Our subjects with unilateral chronic ankle sprains had weaker hip abduction strength and less plantar-flexion range of motion on the involved sides. Clinicians should consider exercises to increase hip abduction strength when developing rehabilitation programs for patients with ankle sprains.”-Friel et al

Awhile back we wrote about the principle that if the hip abductors are weak, the leg will posture more adducted (ie, cross over type pattern) and this places the foot more directly below the body midline plumb, this will posture the foot in inversion and thus at greater risk for future inversion sprains.  This sets up the vicious cycle of hip abductor weakness, frontal plane drift of pelvis, inversion of the foot and more ankle sprain risks/events.  The cycle must be broken. The hip must be addressed. That lateral chain must be restored all the way up from the foot.  

Another newer study by Bowker discusses the somatosensory feedback necessary for postural adjustments, walking, and running stating that they may be hampered by a decrease in soleus spinal reflex excitability.  The study adds more validity to what we are all growing to know more clearly, that the central nervous system via supraspinal circuitry plays deeply into chronic ankle instability (CAI). The studies suggest that CAI may be more about coordination and control of dynamic stabilizers and changes in the motor neuron excitability rather than the function of static stabilizers.

“A successful reorganization of the sensorimotor system after an initial ankle sprain is the critical point when individuals suffer chronic ankle instability or become copers [individuals who do not develop chronic instability after an ankle sprain] who break the cycle of recurrent injuries and disabilities seen in CAI,” Masafumi Terada, PhD

According to LER and the Terada work, 

The slow-twitch fibers in the soleus muscle are mostly innervated by small alpha motoneurons, Terada explained, so the study findings suggest that some people may restore their ability to reflexively recruit alpha motoneurons after ankle injury, and some may not.

“Therapeutic interventions that can increase the H-reflex in the soleus may help to break the cycle of recurrent injuries and disabilities seen in CAI,” he said. “Lower-intensity transcutaneous electrical stimulation, joint manipulations, and reflex conditioning protocols may be effective in increasing the soleus spinal excitability.”

The Gait Guys

Reference:

CAI and the CNS: Excitability may influence instability. Larry Hand

http://lermagazine.com/news/in-the-moment-sports-medicine/cai-and-the-cns-excitability-may-influence-instability

Taken from original source:

Bowker S, Terada, M, Thomas AC, et al. Neural excitability and joint laxity in chronic ankle instability, coper, and control groups. J Athl Train 2016 Apr 11. [Epub ahead of print]

J Athl Train. 2006; 41(1): 74–78.PMCID: PMC1421486Ipsilateral Hip Abductor Weakness After Inversion Ankle SprainKaren Friel,Nancy McLean,Christine Myers, and Maria Caceres
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1421486/

The diaphragm and chronic ankle instability.

I have been treating the global manifestations of unaddressed chronic ankle sprains for decades now. I am never unsurprised to find frontal plane hip weakness and dysfunction of the same side obliques , shoulder and spinal stabilizers. Here is one more piece of proof that unaddressed ankles are monster problems, slowly eroding the stability of the system.
But, shame on those who attempt to simplify this, just correcting the breathing and throwing some corrective spinal stability work at this problem. This approach will fail, repeatedly. At some point the ankle has to be addressed and the impaired supra spinal programming. Gait will have to be retrained as well, forget to do this and your efforts will be muted.
-Dr. Allen

“Previous investigations have identified impaired trunk and postural stability in individuals with chronic ankle instability (CAI). The diaphragm muscle contributes to trunk and postural stability by modulating the intra-abdominal pressure. A potential mechanism that could help to explain trunk and postural stability deficits may be related to altered diaphragm function due to supraspinal sensorimotor changes with CAI.”

Reference:

Diaphragm Contractility in Individuals with Chronic Ankle Instability.

Terada, Masafumi; Kosik, Kyle B.; McCann, Ryan S.; Gribble, Phillip A.  Medicine & Science in Sports & Exercise:

http://journals.lww.com/acsm-msse/Abstract/publishahead/Diaphragm_Contractility_in_Individuals_with.97497.aspx

Ankle spains and hip abductors

We see it ALL THE TIME. But sometimes it is nice to point out the obvious, just in case you are not looking for it.
“Conclusions: Our subjects with unilateral chronic ankle sprains had weaker hip abduction strength and less plantar-flexion range of motion on the involved sides. Clinicians should consider exercises to increase hip abduction strength when developing rehabilitation programs for patients with ankle sprains.”-Friel et al
Dr. Allen: if the hip abductors are weak, the leg will posture more adducted (ie, cross over type pattern) and this places the foot more directly below the body midline plumb, this will posture the foot in inversion and thus at greater risk for future inversion sprains.  This sets up the vicious cycle of hip abductor weakness, frontal plane drift of pelvis, inversion of the foot and more ankle sprain risks/events.  The cycle must be broken. The hip must be addressed. That lateral chain must be restored all the way up from the foot.  All stuff you likely already know, but good to find another study to validate.

Dr. Allen

J Athl Train. 2006; 41(1): 74–78.PMCID: PMC1421486Ipsilateral Hip Abductor Weakness After Inversion Ankle SprainKaren Friel,Nancy McLean,Christine Myers, and Maria Caceres
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1421486/

Podcast 91: Gait, Vision & some truths about leg length discrepancies

Show sponsors:
www.newbalancechicago.com

A. Link to our server:
http://traffic.libsyn.com/thegaitguys/pod_91f.mp3

Direct Download:
http://thegaitguys.libsyn.com/91

Other Gait Guys stuff

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

C. Gait Guys online /download store (National Shoe Fit Certification and more !) :
http://store.payloadz.com/results/results.aspx?m=80204

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:

Amazon/Kindle:

http://www.amazon.com/Pedographs-Gait-Analysis-Clinical-Studies-ebook/dp/B00AC18M3E

Barnes and Noble / Nook Reader:

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Hardcopy available from our publisher:

http://bookstore.trafford.com/Products/SKU-000155825/Pedographs-and-Gait-Analysis.aspx

Show notes:

Gait and vision: Gaze Fixation
What’s Up With That: Birds Bob Their Heads When They Walk
http://www.wired.com/2015/01/whats-birds-bob-heads-walk/
 
Shod vs unshod
 
Short leg talk:
11 strategies to negotiate around a leg length discrepancy

From a Reader:

Dear Gait Guys, Dr. Shawn and Dr. Ivo,  I was referred to this post of yours on hip IR…http://thegaitguys.tumblr.com/post/14262793786/gait-problem-the-solitary-externally-rotated   I am impressed by the level of details of your understanding of the gait and biomechanics. Although I am still trying to understand all of your points in this post, I would like to ask you:  What if my IR is limited due to a structural issue? The acetabular retroversion of the right hip in my case. 

I.e. if I am structurally unable to rotate the hip internally.
What will happen? 
What would be a solution to the problem in that case? 

Single-leg drop landing movement strategies 6 months following first-time acute lateral ankle sprain injury – Doherty – 2014 – Scandinavian Journal of Medicine & Science in Sports
http://onlinelibrary.wiley.com/doi/10.1111/sms.12390/abstract

Hey Gait Guys,

I understand that 1st MP Joint dorsiflexion, ankle rocker, and hip extension are 3 key factors for moving in the sagittal plane from your blog and podcasts so far. I really love how you guys drill in our heads to increase anterior strength to increase posterior length to further ankle rocker. I’ve seen the shuffle gait and was curious if you had a good hip extension exercise to really activate the posterior hip extensors and increase anterior length. 

Podcast 52: Limb Dominance & Other Cool Stuff

A. Link to our server:

http://thegaitguys.libsyn.com/podcast-52-limb-dominance-other-cool-stuff

B. iTunes link:

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

C. Gait Guys online /download store (National Shoe Fit Certification and more !) :

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

D. other web based Gait Guys lectures:

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

________________________________________

* Today’s show notes:

Neuroscience:

1. The Potential Downside of Wearable Biomechanical Monitoring Devices for Running

http://runblogger.com/2014/01/downside-of-wearable-biomechanical-monitoring-devices-for-running.html

2. Google’s Next Crazy Project: Smart Contact Lenses | Entrepreneur.com
http://www.entrepreneur.com/article/230927

3. How Humans Burn Fewer Calories Than Other Mammals

http://www.runnersworld.com/weight-loss/how-humans-burn-fewer-calories-than-other-mammals

4. Update: I was listening to your podcast and you said Ice Bug was out of business. I sell them in my store in Fairbanks Alaska where we have snow and ice on the ground for 6-7 months a year. The US distributor is Ice Bug USA. I also carry a the Salomon Snow Cross studded shoe.
The effects of limb dominance and fatigue on running biomechanics
http://www.gaitposture.com/article/S0966-6362(13)00702-9/abstract
5. Email case:
Dear Gaitguys,
   I have been on a search since October to determine the cause of my chronic tendonitis in my knees and right hip. Through my search I was told that my femurs are rotated internally and my tibia are externally rotated. This is causing my patella to face inward.
  I was told by one PT that I will never be able to run long distances without developing tendonitis. I want to believe he is wrong because I love running. I came across something called Femoral Anterior Glide in my research and was wondering if you guys believe this is a real condition. Also is there a way a person can know if they have this problem?
Thank you for all of your great posts!
 Kate 
6. Blog reader:

My 11 year old son walks with a very noticeable external tibial torsion. We just recently noticed this and I came upon your site while trying to research it. I also read that many time it has to do with a problem with the patella. Both my husband and daughter have had patella problems but do not have the duck walk like my son. I did ask a a pediatric sports medicine specialist about the problem and he said some kids just walk that way. Where should I bring my son for help with this?

7. Blog reader asks:

About a year ago there was an article posted called: “A case of the non-resolving ankle sprain. Things to think about when the ankle and foot just do not fully come around after a sprain”. I am 15 weeks into an identical problem and I was wondering if there was any way you guys could follow up with “MR” to see if he was ever able to resolve his issue. It is such a unique and frustrating case (being able to walk but not run) and I haven’t found any other instance of it until now. Thank you.

8. Shoe Fit Certification program
Link:Gait Guys online /download store (National Shoe Fit Certification and more !) :

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

9. Second metatarsal osteotomies for metatarsalgia: A robotic cadaveric study of the effect of osteotomy plane and metatarsal shortening on plantar pressure – Trask – 2013 – Journal of Orthopaedic Research – Wiley Online Library

http://onlinelibrary.wiley.com/doi/10.1002/jor.22524/abstract;jsessionid=BCFFA5207512C41214E7F3D601729EFE.f01t01

Podcast 45: Spock, Ankle Syndesmosis injuries and Subways.

4.Scanadu scores $10.5M and paves the way for FDA trials

5 . National Shoe Fit Program
Knee Surg Sports Traumatol Arthrosc. 2010 Oct;18(10):1379-84. doi: 10.1007/s00167-009-1010-y. Epub 2009 Dec 18.

Rotational laxity greater in patients with contralateral anterior cruciate ligament injury than healthy volunteers. Branch TP, 

 7.from a blog reader:
schwad01 asked you:
Guys. I am a Parkinson’s patient … 
 
8. FAcebook reader:
9. In the News:

Russian Subways Now Accept Squats for Payment

10.In the research:
11.GAME:

Can you see the problem in this runner’s gait ?

You should be able see that they are heel impacting heavy on the outside of the rear foot, and that they are doing so far laterally, more than what is considered normal.  
This is a video of someone with a rear foot varus deformity.
These folks typically have a high arched foot, typically more rigid than flexible, and they are often paired with a forefoot valgus.  
Q: Do you think it might be important as a shoe fitter to know this foot type ?
A: Yes
Q.Should they be put in a shoe with a soft lateral crash zone at the heel ? 
A: No, absolutely not. Why would you want to keep this person deeper and more entrenched on the lateral heel/foot ?!
This foot type has a difficult time progressing off of the lateral foot. The lateral strike pattern and the tendency for the varus rear-foot (inverted)  keeps this person on the lateral aspect of the foot long into midstance.  This eats up time when they should be gradually progressing over to the medial forefoot so that they can get to an effective and efficient medial (big toe) toe off.  This gait type is typically apropulsive, they are not big speed demons and short bursts of acceleration are difficult for these folks much of the time. Combine this person with some torsional issues in  the tibia or femur and you have problems to deal with, including probably challenges for the glutes and patellar tracking dysfunction. What to see some hard, tight IT Bands ?These folks are often the poster child for it. Good luck foam rolling with these clients, they will hate you for recommending it !
They are typically poor pronators so they do not accommodate to uneven terrain well.  Because they are more on the outside of the foot, they may have a greater incidence or risk for inversion sprains. You may choose to add the exercise we presented on Monday (link  here) to help them as best as possible train some improved strength, awareness and motor patterns into their system. In some cases, but only when appropriate, a rear foot post can be used to help them progress more efficiently and safely. 
These foot types typically have dysfunction of the peronei (amongst other things). A weak peroneus longus can lead to a more dorsiflexed first metatarsal compromising the medial foot tripod stability and efficiency during propulsion while also risking compromise to the first metatarsaophalangeal (1st MTP) joint and thus hallux complications.  Additionally, a weak peroneus brevis can enable the rear foot to remain more varus. This muscle helps to invert the rearfoot and subtalar joints. This weakness can play out at terminal swing because the rear foot will not be brought into a more neutral posture prior to the moment of heel/foot strike (it will be left more varus) and then it can also impair mid-to-late midstance when it fires to help evert the lateral column of the foot helping to force the foot roll through to the big toe propulsive phase of terminal stance.  (* children who have these peroneal issues left unaddressed into skeletal maturity are more likely to have these rearfoot varus problems develop into anatomic fixed issues…… form follows function.)
You can see in the video the failed attempt to become propulsive. The client speeds over to the medial foot/big toe at the very last minute but it is largely too late. Sudden and all out pronation at the last minute is also fraught with biomechanical complications.
One must know their foot types. If you do not know what it is you are seeing, AND know how to confirm it on examination you will not get your client in the right shoe or give them the right homework.
* caveat: the mention of Monday’s exercise for this foot type for everyone with Rearfoot varus is not a treatment recommendation for everyone with the foot type. For some people this is the WRONG exercise or it might need modifications. Every case is different. The biomechanics all the way up need to be considered. Medicine is not a compartmentalized art or science. 
Shawn and Ivo, The Gait Guys

 

Can you see the problem in this runner’s gait ?

You should be able see that they are heel impacting heavy on the outside of the rear foot, and that they are doing so far laterally, more than what is considered normal.  
This is a video of someone with a rear foot varus deformity.
These folks typically have a high arched foot, typically more rigid than flexible, and they are often paired with a forefoot valgus.  
Q: Do you think it might be important as a shoe fitter to know this foot type ?
A: Yes
Q.Should they be put in a shoe with a soft lateral crash zone at the heel ? 
A: No, absolutely not. Why would you want to keep this person deeper and more entrenched on the lateral heel/foot ?!
This foot type has a difficult time progressing off of the lateral foot. The lateral strike pattern and the tendency for the varus rear-foot (inverted)  keeps this person on the lateral aspect of the foot long into midstance.  This eats up time when they should be gradually progressing over to the medial forefoot so that they can get to an effective and efficient medial (big toe) toe off.  This gait type is typically apropulsive, they are not big speed demons and short bursts of acceleration are difficult for these folks much of the time. Combine this person with some torsional issues in  the tibia or femur and you have problems to deal with, including probably challenges for the glutes and patellar tracking dysfunction. What to see some hard, tight IT Bands ?These folks are often the poster child for it. Good luck foam rolling with these clients, they will hate you for recommending it !
They are typically poor pronators so they do not accommodate to uneven terrain well.  Because they are more on the outside of the foot, they may have a greater incidence or risk for inversion sprains. You may choose to add the exercise we presented on Monday (link  here) to help them as best as possible train some improved strength, awareness and motor patterns into their system. In some cases, but only when appropriate, a rear foot post can be used to help them progress more efficiently and safely. 
These foot types typically have dysfunction of the peronei (amongst other things). A weak peroneus longus can lead to a more dorsiflexed first metatarsal compromising the medial foot tripod stability and efficiency during propulsion while also risking compromise to the first metatarsaophalangeal (1st MTP) joint and thus hallux complications.  Additionally, a weak peroneus brevis can enable the rear foot to remain more varus. This muscle helps to invert the rearfoot and subtalar joints. This weakness can play out at terminal swing because the rear foot will not be brought into a more neutral posture prior to the moment of heel/foot strike (it will be left more varus) and then it can also impair mid-to-late midstance when it fires to help evert the lateral column of the foot helping to force the foot roll through to the big toe propulsive phase of terminal stance.  (* children who have these peroneal issues left unaddressed into skeletal maturity are more likely to have these rearfoot varus problems develop into anatomic fixed issues…… form follows function.)
You can see in the video the failed attempt to become propulsive. The client speeds over to the medial foot/big toe at the very last minute but it is largely too late. Sudden and all out pronation at the last minute is also fraught with biomechanical complications.
One must know their foot types. If you do not know what it is you are seeing, AND know how to confirm it on examination you will not get your client in the right shoe or give them the right homework.
* caveat: the mention of Monday’s exercise for this foot type for everyone with Rearfoot varus is not a treatment recommendation for everyone with the foot type. For some people this is the WRONG exercise or it might need modifications. Every case is different. The biomechanics all the way up need to be considered. Medicine is not a compartmentalized art or science. 
Shawn and Ivo, The Gait Guys

 

The “Top-End” Peroneal Walk Foot Skill: Another Restoration Foot Trick by The Gait Guys

Have stability problems in your ankles ? Lots of people do !
Here is a brief video of a simple, but difficult, functional exercise to strengthen the peroneal muscles in full plantar flexion (we will give more detailed tricks and techniques away on the Foot-Ankle DVD exercise series, once we get some time to get to it !). The key here is to not let the heel drop during single fore-foot loading and to keep the ankle pressing inwards as if to try and touch the ankles together medially …..if you feel the heel drop on the single foot loaded side (or you can feel the calf is weaker or if you feel strain to keep the inward press of the ankle) then it might be more than the peronei, it could be the combined peroneal-gastrocsoleus complex. The key to the assessment and home work is to make sure that the heel always stays in “top-end” heel rise plantarflexion. But you have to strongly consider the peronei just as seriously. Studies show that even single event sprains let alone chronic ankle sprains create serious incompetence of the peronei. Most people do not notice this because they never assess the ability to hold the foot in full heel rise (plantarflexion) while creating a valgus load (created by the peronei mostly, a less amount from the lateral calf) at the ankle. This is why repetitive sprains occur. The true key to recovery is to be able to walk on the foot in this heel-up “top-end” position while in ankle eversion (ankles squeezed together) as you see in this video. This is something we do with all of our basketball and jumping sports athletes and it is critical in our dancers of all kinds. And if they cannot do the walking skill or if they feel weakness then we keep it static and put a densely rolled towel or a small air filled ball between the ankles and have them do slow calf raises and descents while squeezing the towel-ball with all their ability. This will create a nice burn in the peroneal muscles after just a few repetitions. The user will also quickly become acutely aware of their old tendency to roll to the outside of the foot and ankle because of this lack of awareness and strength of those laterally placed ankle evertors – the peronei. It is critical to note that If you return to the ground from a jump and cannot FIRST load the forefoot squarely and then, and only then, control the rate of ankle inversion and neutral heel drop (ankle dorsiflexion) then you should not be shocked at chronic repetitive ankle sprains. Remember, the metatarsals and toes are shorter as we move away from the big toe, so there is already a huge risk and tendency to roll to the outside of the foot through ankle inversion. Hence why ankle sprains are so common. We call this “top end” peroneal strength but for it to be effectively implemented one must have sufficient top end calf strength as well, you cannot have sound loading mechanics without both.
It is not as easy as it appears in this video. We encourage you to give this a try and we bet that 1 out of every 2 people who try it will notice “top end” weakness felt either in the peronei and/or in the calf via inability to keep the heel in “top-end”. Oh, and do not think that you can simply correct this by more calf work, not if the peronei are involved, which they usually are.
One more trick by The Gait Guys………bet you cannot wait for the foot dvd huh !? Ya, it has only been on our list for 3 years now !
 We talk more about this kind of stuff on our National Shoe Fit Certification program.
Email us if you are interested thegaitguys@gmail.com