Podcast 169: Foot muscles, core strength and more

Podcast 167: Foot muscles, core strength and more

Join us each month on the Masterclass in Gait, link below

https://www.patreon.com/thegaitguys

Join at the $40 monthly level and get the masterclass each month, bonus material and the detailed monthly content we only share on Patreon.

The Masterclass is a formal LIVE presentation of slides, videos, demos, deep dives on topics you will not hear anywhere but here ! We hit the gait, biomechanics, neurology and orthopedics of all of the gait topics we present. This is not for the weak and timid, this is the deep dive you have been waiting for. Join us while we turn our normal 50 minute presentations into 3.5 hours on a regular basis ! The 40$ Patreon level will give you the Masterclass and also get you the $20, $10, and 5$ Patreon level content. What a deal ! It will not be here forever so lock in now !

Or, you can get less for your money (why would you do that?) and just buy our Monthly $40 Masterclass at our VIMEO on demand page: https://vimeo.com/ondemand/thegaitmasterclass


Links to find the podcast:
Look for us on Apple Podcasts, Google Play, Podbean, PlayerFM, RADIO and more.
Just Google "the gait guys podcast".

https://traffic.libsyn.com/secure/thegaitguys/pod_169_March_12_-_32821_10.19_AM.mp3

https://thegaitguys.libsyn.com/gait-speed-hip-extension-and-a-new-dawn

https://directory.libsyn.com/episode/index/id/18496787
_______________________________________________________________________________
Our Websites:
www.thegaitguys.com
Find Exclusive content at: https://www.patreon.com/thegaitguys
doctorallen.co
summitchiroandrehab.com
shawnallen.net

Our website is all you need to remember. Everything you want, need and wish for is right there on the site.
Interested in our stuff ? Want to buy some of our lectures or our National Shoe Fit program? Click here (thegaitguys.com or thegaitguys.tumblr.com) and you will come to our websites. In the tabs, you will find tabs for STORE, SEMINARS, BOOK etc. We also lecture every 3rd Wednesday of the month on onlineCE.com. We have an extensive catalogued library of our courses there, you can take them any time for a nominal fee (~$20).

Our podcast is on iTunes and just about every other podcast harbor site, just google "the gait guys podcast", you will find us.

Where to find us, the podcast Links:
Apple podcasts:
https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138?mt=2

Google Play:
https://play.google.com/music/m/Icdfyphojzy3drj2tsxaxuadiue?t=The_Gait_Guys_Podcast

Podcast links:

https://traffic.libsyn.com/secure/thegaitguys/168_feb_12.2021_-_4321.mp3

https://thegaitguys.libsyn.com/pod-foot-muscles-core-strength-and-more

https://directory.libsyn.com/episode/index/id/18589871

Irene Davis, PhD, PT

@IreneSDavis

Numerous studies demo foot muscle hypertrophy when removing support of the arch. While it seems intuitive, this is the first published study to demo that adding support results in foot muscle atrophy after only 12 weeks of orthotic use! Nice work!! #strengtheningoverbracing

https://journals.sagepub.com/doi/abs/10.1177/0363546520969205

Foot Core Training to Prevent Running-Related Injuries: A Survival Analysis of a Single-Blind, Randomized Controlled Trial
Ulisses T. Taddei, PhD, PT, Alessandra B. Matias, MSc, PT, Marcos Duarte, PhD,

https://twitter.com/IreneSDavis/status/1306033740020408320/photo/1

https://pubmed.ncbi.nlm.nih.gov/32521283/

2020 Aug;78:105063. clinbiomech.2020.105063.
The effect of a 12-week custom foot orthotic intervention on muscle size and muscle activity of the intrinsic foot muscle of young adults during gait termination
Katrina Protopapas 1 , Stephen D Perry 2

_______

hip abduction

https://www.tandfonline.com/doi/abs/10.1080/02640414.2020.1820183?journalCode=rjsp2

Inter-limb strength asymmetry in adolescent distance runners: Test-retest reliability and relationships with performance and running economy
Rich Blagrove

Summary: Key finding: Larger hip abduction asymmetry associated with worse running economy in female runners (r = 0.85).

____________

Developing neurplasticity

SPlit treadmills , limping,

https://pubmed.ncbi.nlm.nih.gov/23312637/

_____________

quick talk on bone density

https://twitter.com/rwilly2003/status/1303526386846461952?s=1

https://journals.physiology.org/doi/abs/10.1152/jappl.1992.73.3.1165

Relationship among running mileage, bone density, and serum testosterone in male runners: J. D. MacDougal

Podcast 165: Chronic ankle problems: A long form discussion on functional neurology and biomechanics.

Chronic Ankle Problems: Neurologic effects in functional ankle instability,

Join at the $40 monthly level and get the masterclass each month, bonus material and the detailed monthly content we only share on Patreon.The Masterclass is a formal LIVE presentation of slides, videos, demos, deep dives on topics you will not hear anywhere but here ! We hit the gait, biomechanics, neurology and orthopedics of all of the gait topics we present. This is not for the weak and timid, this is the deep dive you have been waiting for. Join us while we turn our normal 50 minute presentations into 3.5 hours on a regular basis ! The 40$ Patreon level will give you the Masterclass and also get you the $20, $10, and 5$ Patreon level content. What a deal ! It will not be here forever so lock in now !

Or, you can get less for your money (why would you do that?) and just buy our Monthly $40 Masterclass at our VIMEO on demand page: https://vimeo.com/ondemand/thegaitmasterclass


Links to find the podcast:
Look for us on Apple Podcasts, Google Play, Podbean, PlayerFM, RADIO and more.
Just Google "the gait guys podcast".
_______________________________________________________________________________
Our Websites:
www.thegaitguys.com
Find Exclusive content at: https://www.patreon.com/thegaitguys
doctorallen.co
summitchiroandrehab.com
shawnallen.net

Our website is all you need to remember. Everything you want, need and wish for is right there on the site.
Interested in our stuff ? Want to buy some of our lectures or our National Shoe Fit program? Click here (thegaitguys.com or thegaitguys.tumblr.com) and you will come to our websites. In the tabs, you will find tabs for STORE, SEMINARS, BOOK etc. We also lecture every 3rd Wednesday of the month on onlineCE.com. We have an extensive catalogued library of our courses there, you can take them any time for a nominal fee (~$20).

Our podcast is on iTunes and just about every other podcast harbor site, just google "the gait guys podcast", you will find us.

Where to find us, the podcast Links:
Apple podcasts:
https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138?mt=2

Google Play:

https://play.google.com/music/m/Icdfyphojzy3drj2tsxaxuadiue?t=The_Gait_Guys_Podcast

Links for todays show

Direct Download URL:

https://traffic.libsyn.com/secure/thegaitguys/Pod_165_sept_11__-_11120_5.53_PM.mp3

Permalink:

https://thegaitguys.libsyn.com/chronic-ankle-problems-neurologic-effects-in-functional-ankle-instability

Libsyn Directory URL: https://directory.libsyn.com/episode/index/id/16641386

Podcast 163: The hip and foot talk to each other. A research paper.

You cannot miss this mini-podcast. It is an excerpt from our Masterclass program. Come join us monthly on the Masterclass at for the monthly Masterclass installment hour.

https://www.patreon.com/thegaitguys

Formal presentations, slides, videos, demos, deep dives on topics you will not hear anywhere but here ! We hit the gait, biomechanics, neurology and orthopedics of all of the gait topics we present. This is not for the weak and timid, this is the deep dive you have been waiting for. Join us while we turn our normal 50 minute presentations into 3.5 hours on a regular basis ! The 40$ Patreon level will give you 50% off the Masterclass and also get you the $20, $10, and 5$ Patreon level content. What a deal ! It will not be here forever so lock in now !

Or, you can get less for your money (why would you do that?) and just buy our Monthly Masterclass at our VIMEO page: https://vimeo.com/ondemand/thegaitmasterclass


Links to find the podcast:
Look for us on Apple Podcasts, Google Play, Podbean, PlayerFM, RADIO and more.
Just Google "the gait guys podcast".
_______________________________________________________________________________
Our Websites:
www.thegaitguys.com
Find Exclusive content at: https://www.patreon.com/thegaitguys
doctorallen.co
summitchiroandrehab.com
shawnallen.net

Our website is all you need to remember. Everything you want, need and wish for is right there on the site.
Interested in our stuff ? Want to buy some of our lectures or our National Shoe Fit program? Click here (thegaitguys.com or thegaitguys.tumblr.com) and you will come to our websites. In the tabs, you will find tabs for STORE, SEMINARS, BOOK etc. We also lecture every 3rd Wednesday of the month on onlineCE.com. We have an extensive catalogued library of our courses there, you can take them any time for a nominal fee (~$20).

Our podcast is on iTunes and just about every other podcast harbor site, just google "the gait guys podcast", you will find us.

Where to find us, the podcast Links:
Apple podcasts:
https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138?mt=2

Google Play:

https://play.google.com/music/m/Icdfyphojzy3drj2tsxaxuadiue?t=The_Gait_Guys_Podcast

Other locations:

https://traffic.libsyn.com/secure/thegaitguys/163_mini_pod_peronei_-_8120_12.01_PM.mp3

https://thegaitguys.libsyn.com/the-hip-and-foot-talk-to-eachother-really-a-research-paper

https://directory.libsyn.com/episode/index/id/15439292

Today's article link: https://pubmed.ncbi.nlm.nih.gov/32717719/

Podcast 161: Central pattern generators: Why and how movement goes bad

Hello, World!

*The Masterclass in Gait, with the Gait Guys

join us monthly at: https://www.patreon.com/thegaitguys for the monthly Masterclass installment hour. Formal presentations, slides, videos, demos, deep dives on topics you will not hear anywhere but here ! We hit the gait, biomechanics, neurology and orthopedics of all of the gait topics we present. This is not for the weak and timid, this is the deep dive you have been waiting for. Join us while we turn our normal 50 minute presentations into 3.5 hours on a regular basis ! The 40$ Patreon level will give you 50% off the Masterclass and also get you the $20, $10, and 5$ Patreon level content. What a deal ! It will not be here forever so lock in now !

Or, you can get less for your money and just buy our Monthly Masterclass at our VIMEO page: https://vimeo.com/ondemand/thegaitmasterclass

Links to find the podcast:
Look for us on Apple Podcasts, Google Play, Podbean, PlayerFM, RADIO and more.
Just Google "the gait guys podcast".
_______________________________________________________________________________
Our Websites:
www.thegaitguys.com
Find Exclusive content at: https://www.patreon.com/thegaitguys
doctorallen.co
summitchiroandrehab.com
shawnallen.net

Our website is all you need to remember. Everything you want, need and wish for is right there on the site.
Interested in our stuff ? Want to buy some of our lectures or our National Shoe Fit program? Click here (thegaitguys.com or thegaitguys.tumblr.com) and you will come to our websites. In the tabs, you will find tabs for STORE, SEMINARS, BOOK etc. We also lecture every 3rd Wednesday of the month on onlineCE.com. We have an extensive catalogued library of our courses there, you can take them any time for a nominal fee (~$20).

Our podcast is on iTunes and just about every other podcast harbor site, just google "the gait guys podcast", you will find us.

Where to find us, the podcast Links:
Apple podcasts:
https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138?mt=2

Google Play:
https://play.google.com/music/m/Icdfyphojzy3drj2tsxaxuadiue?t=The_Gait_Guys_Podcast

Links to find today's show:
https://traffic.libsyn.com/secure/thegaitguys/pod._163_June_21_-_62120_9.41_AM.mp3
https://thegaitguys.libsyn.com/central-pattern-generators-why-and-how-movement-goes-bad-0
https://directory.libsyn.com/episode/index/id/14905823

Podcast 156: Round 2, Coach Mike Lucchesi: Olympic Trials 2020 Atlanta.

We talk all things training again, a deeper dive follow up to podcast 152 with Coach. Listen to that one as well. Your training will thank you.

Links:

https://www.secondcitytc.com/
www.thegaitguys.com
www.shawnallen.net
www.doctorallen.co

Links to find the podcast:
Look for us on Apple Podcasts, Google Play, Podbean, PlayerFM, RADIO and more.
Just Google "the gait guys podcast".

Our Websites:
www.thegaitguys.com
Find Exclusive content at: https://www.patreon.com/thegaitguys
doctorallen.co
summitchiroandrehab.com
shawnallen.net

Our website is all you need to remember. Everything you want, need and wish for is right there on the site.
Interested in our stuff ? Want to buy some of our lectures or our National Shoe Fit program? Click here (thegaitguys.com or thegaitguys.tumblr.com) and you will come to our websites. In the tabs, you will find tabs for STORE, SEMINARS, BOOK etc. We also lecture every 3rd Wednesday of the month on onlineCE.com. We have an extensive catalogued library of our courses there, you can take them any time for a nominal fee (~$20).

Our podcast is on iTunes and just about every other podcast harbor site, just google "the gait guys podcast", you will find us.

Where to find us, the podcast Links:
Apple podcasts:
https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138?mt=2

Google Play:
https://play.google.com/music/m/Icdfyphojzy3drj2tsxaxuadiue?t=The_Gait_Guys_Podcast

other links for today's show:

http://traffic.libsyn.com/thegaitguys/pod_mikeL2_feb21220Final.mp3
http://thegaitguys.libsyn.com/round-2-coach-mike-lucchesi-olympic-trials-2020-atlanta
http://directory.libsyn.com/episode/index/id/13123520

https://www.secondcitytc.com/
thegaitguys.com
shawnallen.net
doctorallen.co

MasterClass in Gait: Part Zero: The Gait Guys Way

Video Link

The Masterclass: The Gait Guys Way

As promised, a live hour with us, some  structured, some loose and conceptual, but it is our way.  This is part zero, free to everyone.  Part 1 will be recorded in the next 2 weeks. Those classes will be pay per view.  This will be at the least a dozen classed, probably 2 or 3 dozen, we have a lot to teach you.

We  are, as of yet, undecided as to the cost, what Patreon levels get this for free  (likely the 50$ per month). We may  (likely will) parse out big pieces and portions to the 20$ folks for free, included in their monthly donation.   But, do not hold us to this, we are undecided, but we did not want to hold back part ZERO, the rough intro so you can get a feel for us, and the material we are going to teach.   Remember, there will only be 100 live seats when we go live (likely Wednesday nights, or Friday late afternoons Central time), and Patreon folks will get first dibs to fill seats, so check in regularly, we will post a TEXT notification here and give a weeks notice.  For those who cannot get into the LIVE class where we will take LIVE real time questions, just like in a classroom, we will record the classes and harbour them on a service like youtube or vimeo behind a pay wall. You can always take our classes for CEU/CE over on onlineCE.com but these Masterclasses will be far far deeper in content, discussion, case demos, deep dives and open ended discussions.

Until then, enjoy.

Stay tuned !

*video link is above

shawn and ivo

#153, The Podcast Reboot: A Deep dive on knee mechanics, loading and running.

Its 2020 and we are back ! The Gait Guys Podcast Reboot !

Links to find the podcast:
Look for us on Apple Podcasts, Google Play, Podbean, PlayerFM, RADIO and more.
Just Google "the gait guys podcast".

Our Websites:
www.thegaitguys.com
Find Exclusive content at: https://www.patreon.com/thegaitguys
doctorallen.co
summitchiroandrehab.com
shawnallen.net

Our website is all you need to remember. Everything you want, need and wish for is right there on the site.
Interested in our stuff ? Want to buy some of our lectures or our National Shoe Fit program? Click here (thegaitguys.com or thegaitguys.tumblr.com) and you will come to our websites. In the tabs, you will find tabs for STORE, SEMINARS, BOOK etc. We also lecture every 3rd Wednesday of the month on onlineCE.com. We have an extensive catalogued library of our courses there, you can take them any time for a nominal fee (~$20).

Our podcast is on iTunes and just about every other podcast harbor site, just google "the gait guys podcast", you will find us.

Where to find us, the podcast Links:
Apple podcasts:
https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138?mt=2

Google Play:
https://play.google.com/music/m/Icdfyphojzy3drj2tsxaxuadiue?t=The_Gait_Guys_Podcast

other links for today's show:

http://traffic.libsyn.com/thegaitguys/pod_jan10_-_11220.mp3

http://directory.libsyn.com/episode/index/id/12705212

https://oembed.libsyn.com/embed?item_id=12705212

http://thegaitguys.libsyn.com/podcast-reboot-deep-dive-on-knee-mechanics-loading-and-running

The “ banana foot”

So, you see at foot that looks like this and what do you think? What are some of the biomechanical characteristics of people with the foot that when, you bisect the calcaneus, the line passing forward passes lateral to the second metatarsal or a line between the second and third?

This condition can be congenital, in conditions like forefoot adductus or compensatory.

The first thing that springs to mind when we see deformities like this is “things usually occur in threes“. So we would expect to see other anatomical and/or genetic abnormalities. An adducted forefoot, like you see here, often occurs as the result of lack of internal rotation of the hip on that side so therefore will often be present with conditions like internal tibial torsion and femoral retrotorsion, which we often, but not always, see together. Because of the increased gait and foot progression angle in these individuals, the forefoot compensates and adducts to bring the center of gravity more to midline.

Feet like this are often, but not always, cavus and rigid. If it remains in relative supination (plantarflexion, abduction and inversion) it is an excellent level but poor shock absorber.

Forefoot adduction can also be a compensation pattern if an individual is unable to get the head of their first ray completely down to the ground. It could be a true forefoot varus or more commonly, a forefoot supinatus; either results in an inability to get the first ray down. This often causes the foot to adduct in compensation, and, due to the tarsal articulations, often raises the base of the first metatarsal increasing the inclination angle of the first ray. This frequently leads to limited dorsiflexion of the first metatarsophalangeal articulation.

So what is a clinician to do?

Ensure that the mechanics of the foot are clean through manipulation and mobilization

Make sure there are appropriate flexors/extensor ratios of skill, endurance, and strength of the foot musculature both intrinsically and extrinsically. This means making sure that the long flexors and extensors are in some degree of balance.

Work on balance and coordination of the lower extremity. This can be impeded if they’re unable to get ahead of the first right down to the ground. Exercises for the peroneus longus, extensor hallucis brevis and short flexors of the foot will often help with this.

“Banana foot”. Coming to your clinic, or a clinic near you. Maybe today…

Dr. Ivo Waerlop, one of The Gait Guys.

#forefootadductus #bananafoot #supination #thegaitguys

Determining foot types...In a nutshell

We talked yesterday about how foot types (i.e., the forefoot to rear foot relationship) can often produce predictable pathomechanics. Here's How to do it. Pretty basic, eh? Its the characteristics, along with the other anatomical goodies they may have that helps to clinch the diagnosis and dictate treatment.

To find out about how to apply your newfound knowledge, join us tomorrow night on our 3rd Wednesdays tele seminar: Biomechanics 314 on online.com

5 PST, 6MST, 7CST, 8EST

Foot types: do they really matter?

forefoot varus: note how the forefoot is inverted with respect to the rear foot

Foot type. You know what we are talking about. The relation in anatomically and in space of the rear foot to the forefoot. We believe that this anatomical relationship holds key clinical insights to predictable biomechanics in that particular foot type.

Simply put, the rear foot can be either inverted, everted or neutral; Same with the forefoot. If the rear foot is inverted we call that a rearfoot varus. If the foot is inverted we call that a forefoot varus. If the rear foot is everted we call that a rear foot valgus and if the forefoot is inverted we call that a forefoot valgus.

Now think about the simple motions of pronation and supination. Pronation is dorsiflexion, eversion and abduction; supination is plantar flexion, inversion and adduction. If it remains in eversion, we say that it is in vslgus and that means they will be qualities of pronation occurring in that foot while it is on the ground. If the foot is inverted, it will have qualities of supination.

We think of pronation as making the foot into a mobile adapter and supination is making the foot into a rigid lever.

During a typical gait cycle the foot is moving from supination at initial contact/loading response to full pronation at mid stance and then into supination from mid stance to terminal stance/pre-swing. I know that if the foot remains and pronation past mid stance that it is a poor lever and if it remains in supination prior to mid stance it will be a poor shock absorbers. Foot type plays into this displaying or amplifying the characteristics of that particular foot type during the gait cycle: if this occurs at a time other than when it supposed to occur, then we can see predictable biomechanics such as too much pronation resulting in increased rear foot eversion, midfoot collapse, abduction of the forefoot and internal rotation of the knee with most often medial knee fall. Now, consider these mechanics along with any torsions or versions in the lower extremity that the patient may have.

This Wednesday night we will be discussing foot types and their biomechanics. Join us on onlinece .com for Biomechanics 314 6:00 MST

Dr Ivo Waerlop, one of The Gait Guys

Podcast 149: A runner's podcast. Many things running and biomechanics.

Links to find the podcast:
Look for us on iTunes, Google Play, Podbean, PlayerFM and more.
Just Google "the gait guys podcast".

Our Websites:
www.thegaitguys.com
Find Exclusive content at: https://www.patreon.com/thegaitguys
doctorallen.co
summitchiroandrehab.com
shawnallen.net

Our website is all you need to remember. Everything you want, need and wish for is right there on the site.
Interested in our stuff ? Want to buy some of our lectures or our National Shoe Fit program? Click here (thegaitguys.com or thegaitguys.tumblr.com) and you will come to our websites. In the tabs, you will find tabs for STORE, SEMINARS, BOOK etc. We also lecture every 3rd Wednesday of the month on onlineCE.com. We have an extensive catalogued library of our courses there, you can take them any time for a nominal fee (~$20).

Our podcast is on iTunes and just about every other podcast harbor site, just google "the gait guys podcast", you will find us.

Where to find us, the podcast Links:
Apple podcasts:
https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138?mt=2

Google Play:
https://play.google.com/music/m/Icdfyphojzy3drj2tsxaxuadiue?t=The_Gait_Guys_Podcast

Other links:
http://traffic.libsyn.com/thegaitguys/pod_149_-_71319_7.44_AM.mp3
http://thegaitguys.libsyn.com/a-runners-podcast-many-things-running-and-biomechanics
http://directory.libsyn.com/episode/index/id/10506122


Show notes:

Exercise matters
3 months of exercise training reprogrammed the epigenetics of sperm DNA in healthy young men. Exercise silenced genes in sperm DNA involved in schizophrenia, Parkinson's disease, cervical cancer, leukemia, and autism
https://www.ncbi.nlm.nih.gov/pubmed/25864559?dopt=Abstract
Epigenomics. 2015 Aug;7(5):717-31. doi: 10.2217/epi.15.29. Epub 2015 Apr 13.
Genome-wide sperm DNA methylation changes after 3 months of exercise training in humans.
Denham J1, O'Brien BJ2, Harvey JT2, Charchar FJ

Footstrike doesnt matter?
https://www.outsideonline.com/2397214/foot-strike-running-study

Adaptation of Running Biomechanics to Repeated Barefoot Running: A Randomized Controlled Study - Karsten Hollander, Dominik Liebl, Stephanie Meining, Klaus Mattes, Steffen Willwacher, Astrid Zech, 2019
https://journals.sagepub.com/doi/full/10.1177/0363546519849920
Is There an Economical Running Technique? A Review of Modifiable Biomechanical Factors Affecting Running Economy.
Moore IS. Sports Med. 2016.
https://www.ncbi.nlm.nih.gov/m/pubmed/26816209/

Running Technique is an Important Component of Running Economy and Performance.
https://www.ncbi.nlm.nih.gov/m/pubmed/28263283/
Folland JP, et al. Med Sci Sports Exerc. 2017.
https://journals.sagepub.com/doi/full/10.1177/0363546519849920

Important to note though than less vertical oscillation is associated with better economy within groups of distance runners, eg ncbi.nlm.nih.gov/m/pubmed/28263… ; ncbi.nlm.nih.gov/m/pubmed/26816… compliant tendons but greater leg stiffness is the goal for distance runners, correct?

This video shows how end. runners compliance & economy are achieved by greater vertical excursions vs. sprinters who hit hard, get off the ground fast and burn more energy.
https://www.nytimes.com/video/sports/100000004379956/identifying-the-best-way-to-run.html

typically have peak vertical forces of 2.5-3.0 times body weight to offset gravity during contact portion of the stride.
https://www.youtube.com/watch?v=hEnIbklXOiU

Effects of footwear midsole thickness on running biomechanics
Sports Medicine and Biomechanics
Mark H.C. Law, Eric M.F. Choi, Stephanie H.Y. Law, Subrina S.C. Chan , Sonia M.S. Wong, Eric C.K. Ching
https://www.tandfonline.com/doi/abs/10.1080/02640414.2018.1538066?journalCode=rjsp20

Knee muscle forces during walking and running in patellofemoral pain patients and pain-free controls.
Thor F.Besiera, Michael Fredericsona, Garry E.Gold, Gary S.Beaupréd, Scott L.Delp
Journal of Biomechanics Volume 42, Issue 7, 11 May 2009, Pages 898-905
https://www.sciencedirect.com/science/article/abs/pii/S0021929009000396

Podcast 148: A deep dive case study. Plus, Central and Peripheral fatigue explained

tag/key words: gait, gaitproblems, gaitanalysis, forefootrunning, forefootstrike, heelstrike, pronation, central fatigue, peripheral fatigue, fatigue, hip rotation, gait biomechanics, running

Links to find the podcast:
Look for us on iTunes, Google Play, Podbean, PlayerFM, Radio.com and more.
Just Google "the gait guys podcast".

Our Websites:
www.thegaitguys.com
Find Exclusive content at: https://www.patreon.com/thegaitguys
doctorallen.co
summitchiroandrehab.com
shawnallen.net

Our website is all you need to remember. Everything you want, need and wish for is right there on the site.
Interested in our stuff ? Want to buy some of our lectures or our National Shoe Fit program? Click here (thegaitguys.com or thegaitguys.tumblr.com) and you will come to our websites. In the tabs, you will find tabs for STORE, SEMINARS, BOOK etc. We also lecture every 3rd Wednesday of the month on onlineCE.com. We have an extensive catalogued library of our courses there, you can take them any time for a nominal fee (~$20).

Our podcast is on iTunes and just about every other podcast harbor site, just google "the gait guys podcast", you will find us.

Where to find us, the podcast Links:

iTunes page:
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1st MTP Pain? The Biomechanics of the Big Toe...

Remember the rockers? We have done a series on this in the past. Remember there are three: heel, ankle and forefoot. We are going to concentrate on the forefoot today.

As a reminder, forefoot rocker occurs at the 1st metatarsal phalangeal joint (big toe knuckle) as the tibia progresses over the forefoot during forward movement. You NEED 50 degrees to do this competently; you SHOULD have 65 degrees. When you don’t, you have a condition called hallux limitus. This could be from a number of reasons, from overpronation in the mid foot, to a bunion, to faulty firing patterns of the muscles which help to descend the 1st ray (the extensor hallucinations brevis, the peroneus longs and the short flexors off the toes). Pretty much, ANYTHING that causes a dorsal and posterior shift of the 1st MTP axis will cause limited forefoot rocker.

So, the question is, “Do you know where 1st 1st MTP pain may be coming from? How familiar are you with the mechanics of that joint?”

Take a few minutes to review it in this video with Dr Ivo Waerlop of The Gait Guys.

#gait, #gaitanalysis, #1stmtp, #forefootrocker, #thegaitguys,

Toes Spacers, anyone?

Less pain through better mechanics?

We have been using toe separators for various foot problems like hallux valgus, hammer toes and flexor dominance/extensor weakness. Our reasoning is that through changing the angle of attachment of the muscle, you alter the mechanical advantage of that muscle and help it to work more efficiently. This seems implied in the literature with respect to foot orthoses (1-3) but we could not find any data regarding toe separators. Toe separators DO seem to reduce pain and increase function (4-6). Perhaps this is through better biomechanics, mechanical deformation, proprioceptive changes, or most likely a combination of all these factors and more.  We think clinical results speak volumes. It is nice to see more data coming out on these easy to implement clinical tools. 

What is you clinical reasoning or rationale for using these devices? We would love to hear and if you have an article for reference you could share, that would be great. 

1. Scherer PR, Sanders J, Eldredge DE, Duffy SJ, Lee RY. Effect of functional foot orthoses on first metatarsophalangeal joint dorsiflexion in stance and gait. J Am Podiatr Med Assoc. 2006 Nov-Dec;96(6):474-81.

2. Halstead J, Chapman GJ, Gray JC, Grainger AJ, Brown S, Wilkins RA, Roddy E, Helliwell PS, Keenan AM, Redmond ACFoot orthoses in the treatment of symptomatic midfoot osteoarthritis using clinical and biomechanical outcomes: a randomised feasibility study. Clin Rheumatol. 2016 Apr;35(4):987-96. doi: 10.1007/s10067-015-2946-6. Epub 2015 Apr 28.

3. Bishop C, Arnold JB, May T. Effects of Taping and Orthoses on Foot Biomechanics in Adults with Flat-Arched Feet. Med Sci Sports Exerc. 2016 Apr;48(4):689-96. doi: 10.1249/MSS.0000000000000807.

4. Chadchavalpanichaya N, Prakotmongkol V, Polhan N, Rayothee P, Seng-Iad S. Effectiveness of the custom-mold room temperature vulcanizing silicone toe separator on hallux valgus: A prospective, randomized single-blinded controlled trial. Prosthet Orthot Int. 2017 Mar 1:309364617698518. doi: 10.1177/0309364617698518. [Epub ahead of print]

5. Tehraninasr A, Saeedi H, Forogh B, Bahramizadeh M, Keyhani MR. Effects of insole with toe-separator and night splint on patients with painful hallux valgus: a comparative study. Prosthet Orthot Int. 2008 Mar;32(1):79-83. doi: 10.1080/03093640701669074.

6. Tang SF, Chen CP, Pan JL, Chen JL, Leong CP, Chu NK. The effects of a new foot-toe orthosis in treating painful hallux valgus. Arch Phys Med Rehabil. 2002 Dec;83(12):1792-5. 

The Knee and Macerating Menisci

Take a good look at the above 2 slides.

Notice that, during pronation, there is a medial rotation of the lower leg and thigh. We remember that, during pronation, the talus plantar flexes, adducts, and everts. This anterior translation and medial rotation of the talus causes the tibia and subsequently the femur to follow. This, if everything is working right, results in medial rotation of the knee.

From the slides, it should also be evident that the medial condyle of the femur and a medial tibial plateau are larger than the lateral. This allows for an increased amount of internal and external rotation of the knee. We remember that the meniscus, like a washer, is between the tibia and femur. We if you think about this kinematically, it would make sense that the tibia, during pronation (which occurs from initial contact to mid stance) would have to rotate faster than the femur otherwise the meniscus would be caught "in between". If there is a mismatch in timing, the meniscus is "caught in the middle", which causes undue stress and can cause fraying, degeneration, etc.

Likewise, during supination (from mid stance to pre swing) the femur must externally rotate faster then the tibia, otherwise we see this same "mismatch". This is a scenario we commonly see in folks who over pronate at the mid foot and remain in pronation for too omg a period of time. 

We think of pronation as being initiated from the movement described above by the talus, and it is attenuated by the popliteus muscle as well as some of the deep flexors of the foot, which fire mostly during stance phase. You will notice that the popliteus  is eccentrically contracting at this point.

Supination, initiated by swing phase of the opposite leg and momentum, is assisted by concentric contraction of the popliteus muscle, internal rotation of the pelvis on the stance phase leg, contraction of the vastus medialis, deep flexors of the foot and peroneii.

Taking moment to "wrap your head around" this concept. Now you can see how complicated it can be when we started to throw in femoral and tibial torsions as well as possibly some orthotic therapy. For example, in an individual with internal tibial torsion, if you do not valgus post the forefoot of the orthotic, the knee is placed at outside the sagittal plane in external rotation further by the orthotic and this thwarts the function of his mechanism, leaving the meniscus holding the bag. 

Know your anatomy and know what is supposed to be firing when, your patients and clients knees depend on it!

Does gait (re)training alter peoples biomechanics? 

You bet it does! Should we be retraining peoples gait? We like to think, yes. What do you think?

“Overall, this systematic review shows that many biomechanical parameters can be altered by running modification training programmes. These interventions result in short term small to large effects on kinetic, kinematic and spatiotemporal outcomes during running. In general, runners tend to employ a distal strategy of gait modification unless given specific cues. The most effective strategy for reducing high-risk factors for running-related injury-such as impact loading-was through real-time feedback of kinetics and/or kinematics.’

Br J Sports Med. 2015 Jun 23. pii: bjsports-2014-094393. doi: 10.1136/bjsports-2014-094393. [Epub ahead of print]
Gait modifications to change lower extremity gait biomechanics in runners: a systematic review.
Napier C1, Cochrane CK1, Taunton JE2, Hunt MA1.

Proprioception trumps Biomechanics

As I sit here on a rare Friday afternoon, not working (OK, I am writing this, so sort of working) and looking out at the lake (picture above), while on a family camping trip, I think about a walk on the rocks this morning with my kids. I was watching my very skilled 7 year old jump from rock to rock while my 3 ½ year old, that thinks he is seven, tried to follow his older brother.

I had my foot on a rock which lowered the front of my foot in plantar flexion and stood on that leg. I noticed that my balance was not as great as it was when my foot was in dorsiflexion. This made me think about pronation and supination. Yes, it is not uncommon for me to think about such things, especially when I have some spare time. That is one of the things about being a foot and gait nerd; these sorts of things are always on our minds.

So, why was my balance off? Did I need more proprioceptive work? Were my foot intrinsics having issues? No, it was something much more mundane.

Pronation consists of dorsiflexion, eversion and abduction. This places the foot in a  “mobile adaptor” posture, reminiscent of our hunter/gatherer ancestors, who needed to adapt to uneven surfaces while walking over terra firma barefoot. Supination, on the other hand (which is the position my foot was in), consists of plantarflexion, inversion and adduction. It places the foot (particularly the midtarsals) in a locked position for propulsion (think of the foot position during toe off).

So why when my foot was plantar flexed and adducted while standing on this rock so much more unstable in this supposedly more stable, supinated position? I would encourage you, at this point, to try this so you can see what I mean. When I placed my foot in dorsiflexion on the rock, I was much more stable. A most interesting conundrum for a biomechanist.

Experimenting for a few minutes, alternating plantar flexion and dorsi flexion, gave me the answer. When we are walking on the flats, our foot is (usually) not pushed to the extremes of dorsiflexion; with the front of the foot up on a rock, it is much more so. This “extra” upward force on the front of the foot, provides much more sensory input (and thus proprioception) from the ball of the feet. Take a look at the sensory homunculus and you can see how much brain real estate is dedicated to your foot, especially the front portion. With this information, we are able to apply more  force through the posterior compartment of the leg,which is stronger than my anterior compartment (as it is with most folks).

When the front of your foot is in plantar flexion (ie, your heel is on the rock), we have less sensory input to the balls of the feet, and rely more on the anterior compartment (weaker in many folks, including myself) to counterbalance the weight of our body.

Mystery solved: proprioception trumps biomechanics; more proof that the brain is smarter than we are.

The Gait Guys. Solving the worlds great gait questions, one at a time.

So you want to do a Gait Analysis: Part 3

This is the third in a multi part series. If you missed part 1, click here. For part 2, click here.

 Again, a quick review of the walking gait cycle components:

There are two phases of gait: stance and swing. 

Stance consists of:

• Initial contact
• Loading response
• Midstance
• Terminal stance
• Pre-swing

Swing consists of:

• initial (early) swing
• mid swing
• terminal (late) swing

today, lets explore Midstance

we remember that midstance is the mid point of the stance phase of the gait cycle. It is when the maximal amount of midfoot pronation should be occurring

Lets look at what is happening here at the major anatomical areas:

Foot

• Pronation begins: The talus should have slid anteriorly on the calcaneus and it then plantar flexed, everted and adducted to its greatest degree. The subtalar joint should have its axes parallel with the calcaneocuboid joint, essentially “unlocking” the midfoot.  This allows the midfoot to assist in absorbing shock, along with knee flexion, hip flexion and a dip of the contralateral pelvis.
  

•  the calcaneus everts to a max of approximately 5-8°

•  the center of gravity of the foot is lowest at this point, and the ankle mortise its deepest. 

• The lower leg should be internally rotated (as it follows the talus) 4-6°

• The thigh should follow the lower leg and should also be internally rotated 4-6°; sometimes to a greater extent due to the shape and size of the medial condyle of the femur (which is larger than the lateral)

• these actions are (still) attenuated by eccentric action of both the long flexors and extensors of the ankle, as well as the foot intrinsics

Ankle

• The ankle should be neutral, as it should be at the mid point of ankle rocker

Knee

• Flexion to 20°. This is attenuated largely by the quadriceps, contracting eccentrically. The popliteus has often concentrically contracting to assist in internal rotation of the thigh up until midstance. It is quiescent at midstance and will begin to contract eccentrically as soon as the knee passes midstance.

Hip

• The hip is at full flexion at loading response, decreasing as it approached midtsnce and now begins to extend. This is facilitated by a brief contraction of the gluteus maximus (which started at initial contact)

Can you see what is happening? Try and visualize this in your mind. Can you understand why you need to know what is going on at each phase to be able to identify problems? If you don’t know what normal looks like, you will have a tougher time figuring out what is abnormal.

Ivo and Shawn. Gait and foot geeks extraordinaire. Helping you to build a better foundation to put all this stuff you are learning on.

Take a look at this gal.

Why does she have a cross over gait?

• note how much tibial varum she has (curvature of the tibial in the coronal plane)
• how much adduction of the right foot there is, potentially indicating a tight posterior compartment, or perhaps a loss of internal rotation of the right thigh
• the excessive posterior rotation of the left shoulder and upper body
• the subtle abduction of the right arm compared to the left
• the slight torso lean to the left

The correct answer is we don’t know until we examine her. Maybe is is there out of necessity or perhaps it is a more efficient running style for her. Here are some points:

Technical Issues with the crossover gait

The cross over gait may be:

• a more efficient running style
• a potential pathologic musculoskeletal motor pattern
• better for long distance runners
• a challenge to balance because of a narrower base of support

It may also be related to:

• a weak gluteus medius
• weak adductors
• excessive foot pronation
• lower extremity morpholgy (like tibial varum, forefoot varus)
• a weak vastus medialis
• a weak tibialis posterior
• and the list goes on

Join us, tomorrow, Wednesday evening, 8pm EST, 7 CST, 6 MST, 5PCT for an hour of crossover gait on chirocredit.com or onlinece.com for Biomechanics 316. We look forward to seeing you there..

The Gait Guys: Shawn and Ivo

So you want to do a Gait Analysis: Part 2

This is the second in a multi part series. If you missed part 1, click here.

We have been exploring the gait cycle, one step (literally) at a time. A quick review of the walking gait cycle components:

There are two phases of gait: stance and swing. 

Stance consists of:

• Initial contact
  
• Loading response
• Midstance
• Terminal stance
• Pre-swing

Swing phase:

• initial (early) swing
• mid swing
• terminal (late) swing

today, lets explore Loading Response

we remember that Loading response occurs when there is eight bearing on the loaded extremity from initial contact. This continues until the opposite foot is lifted for swing.

Lets look at what is happening here at the major anatomical areas:

Foot

• Pronation begins: This is when the proverbial “rubber hits the road” occurs. Hopefully the coefficient of friction of the heel with the ground is great enough that pronation of the midfoot begins. As the calcaneus slows, the talus slides anteriorly and plantar flexes, adducts and everts, unlocking the subtalar joint and (hopefully) moving toward making its axis parallel with the calcaneo cuboid joint at midstance (more of that next time).
  

• because of this motion, the calcaneus everts approximately 5°

• both of these motions serve to lower the center of gravity of the leg, deepening the ankle mortise to provide more stability to the ankle

• Both of these motions (especially adduction of the talus) initiate internal rotation of tibia and lower leg

• these actions are attenuated by eccentric action of both the long flexors and extensors of the ankle, as well as the foot intrinsics

Ankle

• The ankle plantar flexes 5-10 °. This motion is attenuated by eccentric action of the anterior compartment muscles of the lower leg
• this serves to absorb shock (remember pronation is a shock absorber? if not, see here)

• Ankle rocker occurs (click here for a review of the rockers of the foot)

Knee

• Flexion to 20°. This is attenuated largely by the quadriceps, contracting eccentrically

Hip

• The hip is at full flexion at loading response and now begins to extend. This is facilitated by a brief contraction of the gluteus maximus (which started at initial contact)

Starting to see what is happening? Can you understand why you need to know what is going on at each phase to be able to identify problems?

We are The Gait Guys. Two geeks spreading the word. WE appreciate your help doing the same.