Subtle clues to flexor dominance

Take a close look at these photographs. Compare the prominence of the extensor tendon‘s left to right. What do you see? Do you notice the deeper furrowing of the extensor tendons on the left? Do you see the subtle increased extension of the metatarsophalangeal and requisite increased flexion of the inter-phalangeal articulations, left versus right? What about the height of the arches?

Keep a keen eye out for subtle signs. They can make a real difference in your clinical diagnosis and results…

Shoe causing knee pain? You decide…

This gentleman presented with left-sided knee pain at the medial collateral ligament. His left foot was planted when he rotated to the left. Take a close look at the shoes in the picture. If you look closely, you will notice the right shoe is tilted on its axis due to a rear foot to forefoot deformity (forefoot supinatus)and the left shoe upper was assembled canted on its axis, Most likely in manufacturing defect. Can you see the subtle valgus in the left shoe rearfoot?

Think of the implications of a shoe with this orientation. Putting the rearfoot in valgus “prepronates“ the foot, causing medial rotation of the tibia and femur and increase valgus stress on the knee, stressing the medial collateral ligament and stabilizing complex. This will most likely manifest itself as anterior rotation of the ilium on the left-hand side with relative posterior rotation on the right and a clockwise Pelvic distortion pattern. With the foot planted on the left side and it being pre-pronated, can you see how the rotation to the left leaves a greater amount of external rotation that must occur to just get the foot to neutral, never mind supination for stability and pushoff?
What about the popliteus having to work on time to assist and extra rotation and the appropriate femoral/tibial rotation ratios to spare the medial meniscus?

These are the kind of things to keep us awake at night…

On the road to a cruciate reconstruction?

While at a recent soccer game, I noticed this gal standing on the side lines. Talk about knee problems waiting to happen ! Note the hyperextended posture of the knees with increase in lumbar lordosis and anterior carriage of the entire pelvis with an increase in the thoracic kyphosis and head forward carriage to match! You can imagine the anterior pelvic tilt as well as stretch weakness of the abdominal obliques creating "core instability". At least she is not wearing heels, although a negative inclination [negative ramp delta] shoe would probably help.

Think of the strain on her poor posterior cruciate ligaments with all of that anterior femoral translation! We remember that the popliteus acts as an "accessory PCL" at initial contact in the gait cycle. It fires at heel strike and again from loading response until toe off

Think about the forces on these knees while descending hills or stairs. The momentum will carry the femur forward (or anteriorly). There needs to be something to reststrain this; enter the PCL. Because of the laxity (and instability), the poplitues will need to fire to take up the slack. We wrote about that here and here.

Note, this is a mere thought experiment, don’t get bent outta shape, these things might not occur, or they might. Time will tell.

Podcast #140: Running, hallux amputation, building deeper gait concepts.

Topics:

hallux amputation, achilles tendon, achilles tendinopathy, rehab achilles, bursae, marathons, vapourfly, shoes, shoe fit, gait, gait problems, gait correction, gait retraining, running, foot strike, heel strike, midfoot strike, rearfoot strike, heel strike, loading responses, gait rehab, muscle strength, isotonics

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

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:

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

Direct download URL: http://traffic.libsyn.com/thegaitguys/pod_140real_-_10618_9.18_AM.mp3

Permalink URL: http://thegaitguys.libsyn.com/podcast-140-running-hallux-amputation-building-running-concepts

Libsyn Directory URL:http://directory.libsyn.com/episode/index/id/7135745

Topics and links:

The tendinopathic Achilles tendon does not remain iso-volumetric upon repeated loading: insights from 3D ultrasound. Nuri L, et al. J Exp Biol. 2017.

https://www.ncbi.nlm.nih.gov/m/pubmed/28620014/

Good tip to decrease loading and help decrease injury risk in runners: See study by Chan et al.:
http://journals.sagepub.com/doi/abs/10.1177/0363546517736277?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub%3Dpubmed&

Vapourfly shoe
https://www.nytimes.com/interactive/2018/07/18/upshot/nike-vaporfly-shoe-strava.html

Men’s marathon:
https://twitter.com/chrisbramah/status/1019481750039343104/photo/1

fun facts:

Foot strike patterns of the World Championships Marathon:
Women’s race:
73% rearfoot, 24% midfoot, 3% forefoot
Men’s race:
67% rearfoot, 30% midfoot, 3% forefoot
pic.twitter.com/iWRzjImQBZ
https://www.iaaf.org/about-iaaf/documents/research#biomechanical-research-projects

Foot structure and stiffness is critical
https://www.nature.com/articles/srep29870

Tendons can change
Progressive calf strength training led to increased achilles stiffness @ 4 weeks & increased tendon cross sectional area @ 8 weeks
https://link.springer.com/article/10.1007/s00421-018-3904-1

Bursae can thicken painlessly as a normal adaption to activity... just like skin calluses!
https://www.ncbi.nlm.nih.gov/pubmed/24907190

Between 63-72% of participants were wearing incorrectly sized footwear. review of the literature here from @LTPodiatry team:
https://jfootankleres.biomedcentral.com/articles/10.1186/s13047-018-0284-z

How Neuroscientists Explain the Mind-Clearing Magic of Running -- from the Science of Us
https://www.huffingtonpost.com/science-of-us/how-neuroscientists-expla_b_9787466.html

And why does this guy have hip pain?

line up the center of the heel counters with the outsoles, and what do you see?

can you see how the heel counter is centered on the outsole, like it is supposed to be

notice how the heel counter of the shoe is canted medially on the outsole of the shoe, creating a varus cant

Take a guy with lower back and left sided sub patellar pain that also has a left anatomically short leg (tibial) and bilateral internal tibial torsion and put him in these baby’s to play pickleball and you have a prescription for disaster.

Folks with an LLD generally (soft rule here) have a tendency to supinate more on the short leg side (in an attempt to make the limb longer) and pronate more on the longer leg side (to make the limb shorter). Supination causes external rotation of the lower limb (remember, we are trying to make the foot into a rigid lever in a “normal” gait cycle). this external rotation with rotate the knee externally (laterally). Folks with internal tibial torsion usually rotate their limb externally to give them a better progression angle (of the foot) so they don’t trip and fall from having their feet pointing inward. This ALSO moves the knee into external rotation (laterally), often moving it OUTSIDE the saggital plane. In this case, the knee, because of the difference in leg length AND internal tibial torsion AND the varus cant of the shoe, has his knee WAY OUTSIDE the saggital plane, causing faulty patellar tracking and LBP.

Moral of the story? When people present with a problem ALWAYS TAKE TIME TO LOOK AT THEIR SHOES!

On the subject of manual muscle work…

image credit: https://commons.wikimedia.org/wiki/File:Muscle_spindle_model.jpg

Here is an older article that may seem verbose, but has interesting implications for practitioners who do manual muscle work with their clients. We would invite you to work your way through the entire article, a little at a time, to fully grasp it’s implications.

Plowing through the neurophysiology, here is a synopsis for you:

Tactile and muscle afferent (or sensory) information travels into the dorsal (or posterior) part of the spinal cord called the “dorsal horn”. This “dorsal horn” is divided into 4 layers; 2 superficial and 2 deep. The superficial layers get their info from the A delta and C fibers (cold, warm, light touch and pain) and the deeper layers get their info from the A alpha and A beta fibers (ie: joint, skin and muscle mechanoreceptors).

So what you may say

The superficial layers are involved with pain and tissue damage modulation, both at the spinal cord level and from descending inhibition from the brain. The deeper layers are involved with apprising the central nervous system about information relating directly to movement (of the skin, joints and muscles).

Information in this deeper layer is much more specific that that entering the more superficial layers. This happens because of 3 reasons:

1. there are more one to one connections of neurons (30% as opposed to 10%) with the information distributed to many pathways in the CNS, instead of just a dedicated few in the more superficial layers

2. the connections in the deeper layers are largely unidirectional and 69% are inhibitory connections (ie they modulate output, rather than input)

3. the connections in the deeper layers use both GABA and Glycine as neurotransmitters (Glycine is a more specific neurotransmitter).

Ok, this is getting long and complex, tell me something useful...

This supports that much of what we do when we do manual therapy on a patient or client is we stimulate inhibitory neurons or interneurons which can either (directly or indirectly)

• inhibit a muscle

• excite a muscle because we inhibited the inhibitory neuron or interneuron acting on it (you see, 2 negatives can be positive)

So, much of what we do is inhibit muscle function, even though the muscle may be testing stronger. Are we inhibiting the antagonist and thus strengthening the agonist? Are we removing the inhibition of the agonist by inhibiting the inhibitory action on it? Whichever it may be, keep in mind we are probably modulating inhibition, rather than creating excitation.

Semantics? Maybe…But we constantly talk about being specific for a fix, not just cover up the compensation. Is it easier to keep filling up the tire (facilitating) or patching the hole (inhibiting). It’s your call

Yan Lu Synaptic Wiring in the Deep Dorsal Horn. Focus on Local Circuit Connections Between Hamster Laminae III and IV Dorsal Horn Neurons J Neurophys Volume 99 Issue 3

March 2008 Pages 1051-1052 link: http://jn.physiology.org/content/99/3/1051