Podcast 98: Stability, Mobility and The Brain

Topics: Plus, the central nervous system’s effects on Chronic Tendonopathies and Gait Problems.

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Show notes:

Stability, Mobility and The Brain plus, the CNS and Chronic Tendonopathies and Gait Problems. We have done 98 podcasts, it is easy to miss one or two, but this is not one of those ones you should pass up. Hope you will join us on the podcast today !


Exercise Pill

Swagger gait in primates

Should we instruct changes in client’s gait ?

The Brain and chronic tendonopathies

Can you believe they missed this? Sometimes you just need to look.

This gal has knee pain on the R a “funny gait” and right sided low back pain in the sacro iliac joint fr the last 3 years. She felt like she needed to keep her right leg bent and her left straight all the time. She was unable to hike or walk distances longer than 1 mile or time longer than 30 minutes without slowing down and having pain. She has had reconstructive surgery on the right knee for an ACL/MCL, physical therapy, medication, counseling and even stroke rehabilitation/gait retraining.

On exam she has a marked genu varus bilaterally. Knee stability is good anterior/posterior drawer; valgus/varus stress. One leg standing with both eyes open is less than 15 seconds, eyes closed is negligible. She has an anatomically short L leg; at least 2 cm which is both tibial and femoral. She was unaware of this and noone had adressed it in any way.

She was given a 10mm sole length lift for the L leg and propriosensory exercises. She was encouraged to walk with a heel to toe gait. She felt 50% better immediately and another 20% after 2 weeks of doing the exercises. She had gone on several 5 mile hikes for over 2 hours with minimal discomfort.

Nothing earth shaking here. Just an exam which covered the basics and some common sense treatment. Too bad they are not all that easy, eh? The takeaway? Look and listen. The problem was on the side opposite her complaint, as it can be many times. Look at the area of chief complaint 1st, but then look everywhere else : ).

Effects of prior hamstring injuries

Previous hamstring injury is associated with altered biceps femoris associated muscle activity and potentially injurious 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,

En Pointe, Demi Pointe, Posterior Impingement ?

When we see pictures like this most of us are triggered to look at the toe and the challenges to the 1st MTP joint.  But what about all that compression and crowding in the back of the ankle ? Posterior compression is a reality in athletes who spend time at end range plantarflexion or pack much force and load through end range plantarflexion.

This is a photo example of what is referred to as “en pointe” which means “on the tip”.  “Demi pointe” means on the ball of the foot which is much safer for many areas of the foot, but this requires adequate 1st MTP (metatarsophalangeal joint range). We discussed this briefly this week on social media regarding hallux limitus and rigidus.

En Pointe is a terrible challenge. So if you are thinking of putting your darling children in ballet…… just beware of the facts and do some logical thinking on your own when it comes to allowing the “en pointe” axially loading of the entire body over a single joint, a type of loading that this joint was never, ever, designed to withstand. This joint is a great problem for a great many in their lives, why start playing with the risk factors so early ? Let them dance, into demi pointe, but pull them once they are being forced in to En Pointe, if you want our opinion on the matter.

En pointe or classical point ballet it typically done in point shoes or slippers which have a reinforced toe box that allows a more squared off stable surface to stand in pointe position.  It does not however allow a reduction in the axial loading that you see in this picture and it certainly does not help with proper angulation of the big toe, if anything the slipper will gently corral the toes together rendering abductor hallucis muscle function nearly obsolete.   The box will also not stop the valgus loading that typically occurs at the joint. Despite what the studies say, this is one we would watch carefully.  Now, there are studies out there that do not support hallux valgus and bunion formation in dancers, we admit that.  However, we are just asking you to use common sense.  If you see a bunion forming, if the toe is getting chronically swollen, if the toe is drifting off line then one must use common sense and assume that the load is exceeding joint integrity.  Prolonged and excessive loading of any joint cartilage is likely to create a risky environment to crack, fissure, wear down or damage the cartilage or the bony surface underneath (subchondral bone).  If you screw up this joint, toe off will be impaired and thus the windlass effect at the joint will be impaired thus leading to a multitude of other dysfunctional foot issues in the years to come.

Now, back to the “en pointe” position.  Did you try it yet ? Heed our warning ! Just trust us, this is bloody hard.  Since serious foot deformities can result from starting pointe too early, pre-professional students do not usually begin dancing en pointe until after the age of 10 or so , remember, the adolescent foot has not completed its bone ossification and the bone growth plates have not closed.  Thus, damage and deformity are to be expected if done at too young an age.  If you asked our opinion on this, we would say to wait until at least the mid-teenage years……. but by that point in the dance world a prodigy would miss her or his opportunity.  Thus, we see the problems from going “en pointe” too early in many. In the dance world, there are other qualifications for dancers before En Pointe is begun. Things like holding turnout, combining center combinations, secure and stable releve, 3rd position, 4th position, 4th croise and 5th position all of which are huge torsional demands on the hips to the feet. Do you want your child undergoing these deforming forces during early osseous development ? 

Achieving en pointe is a process.  There is a progression to get to it.  Every teacher has their own methods but it is not a “just get up on your toes” kind of thing.

Are you a dancer with posterior ankle pain, impingement or disability. The Os trigonum and protruding lateral talar process are two common and well-documented morphological variations associated with posterior ankle impingement in ballet dancers. 

Think this stuff through. If you are going to be treating these things, you have to know the anatomy, loading mechanics and you have to know your sport or art. Dr. Allen was a physician for the world famous Joffrey Ballet for a few years, he knows a thing or two about these issues dancer’s endure. And he still has a few nightmares from time to time over them. 

Dr. Shawn Allen


Clin Anat. 2010 Sep;23(6):613-21. doi: 10.1002/ca.20991.Pathoanatomy of posterior ankle impingement in ballet dancers. Russell JA,Kruse DW, Koutedakis Y, McEwan IM, Wyon M

Custom orthotic or Sham for mid tendon achilles tendonopathy? It doesn’t seem to matter.

This study prescribed eccentric calf exercises along with either a custom or “sham” foot orthosis for 140 people who were randomized as to which group got the real goods and which one did not.  A Victorian Institute Sports Assessment-Achilles questionairre was given at baseline, 1, 3, 6 and 12 months. No statistically significant difference between the groups.


We wonder just what were the custom and sham like? When we use orthoses, we use full arch contact devices. Perhaps the type of orthosis makes a difference? What has been your experience?

Munteanu SE, Scott LA, Bonanno DR, Landorf KB, Pizzari T, Cook JL, Menz HB.  Effectiveness of customised foot orthoses for Achilles tendinopathy: a randomised controlled trial.
Br J Sports Med. 2015 Aug;49(15):989-94. doi: 10.1136/bjsports-2014-093845. Epub 2014 Sep 22.

National Shoe Fit Certification Course

A quote made by a loyal follower on social media:

“someone asked for the best certification/certificate programs out there, and I posted this with a link to your YouTube promo video, even though I haven’t even went through it, yet. Hopefully this drives a handful of coaches your way. There are over 6k coaches in the group.
“National Shoe Fit Program. The most unknown program out there. 2 overwhelmingly smart biomechanical clinicians put together a program to teach people how to integrate foot and shoe anatomy, then apply that to the various foot types to get people standing, walking, running and moving as correctly as they can on a basic level. Good luck trying to correct most of the squatting, deadlifting and Olympic lifting compensations without addressing how the foot interacts with the ground. Good luck trying to improve fitness without addressing gait. Good luck addressing gait without addressing foot types and shoes.”

thanks Michael !  

we blush

Psoas, iliacus. . . .  hip flexors ?

How many times have you heard us say, “hip flexion in the swing phase of gait is not driven by the hip flexors. In swing phase, the psoas and iliacus complex is not a hip flexor initiator, it is a hip flexion perpetuator/” ?
More evidence … . .
“These experiments also showed that the trailing leg is brought forward during the swing phase without activity in the flexor muscles about the hip joint. This was verified by the absence of EMG activity in the iliacus muscle measured by intramuscular wire electrodes. Instead the strong ligaments restricting hip joint extension are stretched during the first half of the swing phase thereby storing elastic energy, which is released during the last half of the stance phase and accelerating the leg into the swing phase. This is considered an important energy conserving feature of human walking. ”


How quickly does your brain start working when you start your client evaluation ?  

Answer: as quickly as possible.

Stepping up to the plate today for the first pitch I see this.  

Do you see the ever so slight evidence of “possible” right toe extensor tone ? It is subtle but it is staring you right in the face if you care to embrace the subtle clue.  From this angle you can see more of the fat pad and plantar aspect of the RIGHT forefoot. The very next thing we did was look at the dorsum of the foot, and yup, more prominent extensor tone, short extensors to be specific.  The next question was why was I seeing this ? Short flexors usually pair with long toe flexors, and that means gripping the ground and distal displacement of the fat pad and even sometimes lumbrical inhibition or frank weakness. Possible attempts to gain more foot purchase on the ground ? Hmmmmm, perhaps.  The client had right hip pain and right lateral sesamoid pain.  Time for an examination to find out the “whys” and then fix things.

The powers of observation should always get your clinical juices flowing. Even the smallest of things should help guide you or at least clue you in to things.

Notice the differences in running (top) vs sprinting (bottom) activation patterns?

This picture (along with the MIchaud muscular firing pattern ones) are becoming some of my favorite ones to talk about. I just stare at them and look for differences and similarities. 

Check out that the abs do not seem to fire in running (in this study at least), but do in sprinting. Note also that most muscles fire longer (and we wil assume harder) during sprinting. Also check out the peroneals, which fire just as the foot touches down in sprinting, probably to make up for the instrinsics not firing, and assist in creating a rigid lever for push off. 

from: Mann et al 1986