Loss of medial tripod

It is Rewind Friday.
Today, we are reaching back to a brief 2009 lecture I did for the local NSCA chapter on the patterns of kinetic chain compensation that match with loss of medial and lateral foot tripod. (video starts at 49 seconds, for some reason)
https://www.youtube.com/watch?v=yeCBGZkNaeM

Loss of medial tripod

Toe sardines. What have we done to our feet ?

Note that form follows function. If you are observant, you will see the deformation of the 5 digit, just like in this case as the quadratus weakens and the long flexors dominate. The toe begins to spin laterally, and thus the plantar toe pad begins to deform medially, look closely, you can see that here in the video.

Does this look like your foot ? There are a few subtle issues here. 

In the foot, the toe that delineates abduction and adduction of the toes is the 2nd toe. The 2nd toe is considered the anatomic middle of the digits and forefoot. Any toe or movement that moves away from the 2nd toe is abduction and any movement towards the 2nd toe is adduction. This is obviously different than in the hand where the 3rd digit, the one you use during road rage, is the reference digit. Next time you are questioned, tell them you threw them your reference finger, not “the bird”, it is a more accurate descriptor.

In this foot, note how neatly and tightly packed the cute little toes are, all snuggled up to their brothers and sisters. Remember, form follows function. Obviously function has been low on these fellas, at least in abduction.  This often comes from snug toe box footwear and lack of abduction (toe spread) use.  But make no mistake, this is a weak foot.

Today we wish to really focus your attention to an old topic, just a revisit. We can see the 4th and 5th toes curl under from the probably weak lateral head of the quadratus plantae thus encouraging unopposed oblique pull of the long flexors of the digits (FDL). See this post here for an explanation of this phenomenon.  There is also obvious imbalance between the long and short flexors and extensors in these toes, the long flexors are expressing more tone, and that means the long extensors are deprived. 

Note that form follows function. If you are observant, you will see the deformation of the 5 digit, just like in this case as the quadratus weakens and the long flexors dominate. The toe begins to spin laterally, and thus the plantar toe pad begins to deform medially, look closely, you can see that here in the video. This spin can carry the toe nail so far laterally sometimes that the nail can begin to touch the ground during gait and cause painful nail lifting with even some losing the nail. 

There is plenty of life left in this foot, but you have to get to it quickly and get them in lower heeled shoes if tolerable and ones with a wider toe box.  The client needs to be retaught how to access the toe extensors and abductors. Lumbrical retraining, which is a recurrent topic here on our blog, should also be instituted. 

Shawn Allen, one of the gait guys

Attempting to regain a level playing ground for your foot.

“Remember, we were born with both our rearfoot and forefoot designed to engage on the same plane (the flat ground). We were not born with the heel raised higher than the forefoot. And, the foot’s many anatomically congruent joint surfaces, their associated ligaments, the lines of tendon pull and all the large and small joint movements and orchestrations with each other are all predicated on this principle of a rearfoot and forefoot on the same plane. This is how our feet were designed from the start.  This is why I like shoes closer to zero drop, when possible, because I know that we are getting closer to enabling the anatomy as it was designed. This is not always possible, feasible, logical or reasonable depending on the problematic clinical presentation and there is plenty of research to challenge this thinking, yet plenty to support is as well. The question is, can you get back to this point after years of footwear compensating ? Or have your feet just changed too much, new acquired bony and joint changes that have too many miles on the new changes ? Perhaps you have spent your first 20-50 years in shoes with heeled shoes of varying heel-ball offset. Maybe you can get back to flat ground, maybe you cannot, but if you can, how long will it take? Months ? Years ?  It all makes sense to me, but does it make sense for your feet and your body biomechanics after all these years ? Time will tell.” -Dr. Allen

Fundamental foot skills everyone should have, subconsciously. This video shows a skill you must own for good foot mechanics. It needs to be present in standing, walking, squatting, jumping and the like. It is the normal baseline infrastructure that you must have every step, every moment of every day. 

Is your foot arch weak ? Still stuffing orthotics and stability shoes up under that falling infrastructure ? Try rebuilding a simple skill first, one that uses the intrinsic anatomy to  help pull the arch up.  If your foot is still flexible, you can likely re-earn much of the lost skills, such as this one. This is a fundamental first piece of our foot, lower limb and gait restoration program. We start here to be sure this skill is present, then add endurance work on it and then eventually strength and gait progressions. This is where it starts for us gang. 

Shawn and Ivo, the gait guys

The all to common case of the Wobbling Hexapod (Tripod) : Is Your Foot hexa/Tripod Stable Enough to Walk or Run without Injury or Problem ?

Note the music we have chosen today. We tried to match the rate of the dancing tibialis anterior tendon to the tempo of the song, just for fun of course. Well, actually, for neurological reasons as well, as with a steady tempo or beat, your nervous system can learn better. Why do you think we teach kids songs to learn (or you can’t get the theme from the “Jetsons” out of your head).

This is a great video. This client has an obvious problem stabilizing the foot tripod during single leg stance as seen here.  There is also evidence of long term tripod problems by the degree of redness and size (although difficult to see on this plane of view) of the medial metatarsophalangeal (MTP) joint (the MPJ or big knuckle joint) just proximal to the big toe.  This is the area of the METatarsal head, the medial aspect of the foot tripod.

As this client moves slowly from stance into a mild single leg squat knee bend the challenges to the foot’s stability, the tripod, become obvious.  Stability is under duress. There is much frontal plane “Checking” or shifting and the tibial and body mass is rocking back and forth on a microscopic level as evidenced by the dancing tibialis tendon at the ankle level.  The medial foot tripod is loading and unloading multiple times a second. 

Is it any shock to you that this person has chronic foot problems which are exacerbated by running ?  Every time this foot hits the ground the foot is trying to find stability. The medial tripod fails and the big knuckle joint (the 1st MPJ or big toe joint) is enlarging from inflammation, uncontrolled loading through the joint, and early cartilage wear and decay, not to mention the knee falling medially to the foot line as well.  Hallux limitus (turf toe) is subclinical at this time, but it is on the menu for a later date. A dorsal crown of osteophytes (the turf toe ridge on the top of the foot) is developing steadily, soon to block out the range necessary for adequate toe off in this client.  And that means a limitation in  hip extension sometime down the road (and premature heel rise……. did you read Wednesday’s blog post on that topic ?).

*addendum:

Take the time to develop the skill. We ask our clients to work on standing with the toes up to find a clean tripod and do some shallow squats working on holding the tripod quietly. Be sure your glutes are in charge, spin of the limb is in part controlled at the core-hip level so that can a primary location to hunt as well. Eventually work into toes pressed flat but be sure the tripod is still valid, esp the medial tripod. Don’t be what Dr. Allen refers to as a “knuckle popper”. No toe curling/hammering either. Keep that glute on. Move the swing leg forward during a lunge, and then behind you during a squat (mimicking early and late midstance phases of gait/running). This will help your brain realize when it needs this stability and it will also act to press you off balance and will make the foot check and challenge. Do this until you feel the foot fatigue on the bottom. Then Stop. Repeat later. If the medial tripod collapses, the knee will drop inwards and excess pronation is inevitable. We modified this with our prescription of the “100 ups”…..combine the two !

Shawn and Ivo … .  comfortably numb.

Once you have been to the Dark Side of the Moon  (and hopefully you didn’t have any Brain Damage) you will know it well and know what to expect when you return again.  Meaning, when you have seen these issues over and over again, hopefully in your daily work if not regularly here at The Gait Guys, you will quickly know what things to assess and look for in your athletes.  And you might just turn into a Pink Floyd fan at the same time, or at least crave some Figgy Pudding (but you have to eat yer’ meat! How can you have any pudding if you don’t eat  yer’ meat?).

The partial truth about the Foot Tripod. The HEXApod.

The gait guys have talked about the foot tripod for a very long time. But the truth of the matter is that it is really a HEXApod. HEXA means 6. And when the foot is properly orientated and engaged on the ground, the 5 metatarsal heads and the heel should all be engaged with the ground, truly making it an asymmetrical hexapod. In an ideal scenario, the foot would be most stable if it looked like the strange symmetrical hexapod above with the contact points equally distributed around a center point. But that is not the human foot and this version of a hexapod is far simpler and likely inferior to the foot hexapod when human locomotion is to be attempted. The human foot is engineering marvel when it works properly.  

Perhaps the best example of what I mean by the foot being a HEXApod is in the pressure diagram above. In that first picture, on the right of that picture, we see multiple pressure points under the metatarsal heads of the right foot.  Minus the missing 1st metatarsal head pressure point (taken over by increased flexor hallucis longus activity represented by increased pressure at the big toe),  this pretty much confirms that the foot is not a tripod, rather a hexapod. The theory of the tripod, the 1st and 5th metatarsal heads and the heel, is only crudely accurate and honest. In this picture case, this person has increased lateral foot weight bearing (possibly why the 1st MET head pressure is absent) and possibly represented by pressure under the base of the 5 metatarsal. This is not normal for most people and if this person could get the 1st MET head down, they might even have a HEPTApod foot structure because of the 5th metatarsal base presentation (which sometimes represents peroneal muscle weakness). 

Where did we lead you astray after all these years of “tripod” talk ? We have always discussed the foot tripod. We have always discussed the imperative need to keep the limb’s plumb line forces within the area represented by the tripod.  If your forces fall more laterally within the tripod, as in this first discussed picture, one is at increased risk of inversion events and the myriad of compensations within the entire body that will occur to prevent that inversion. So again, why the tripod?  Well, it is easier to understand and it serves our clients well when it comes to finding active foot arch restoration as seen in this video of ours here.  But, the truth of the matter is that all of the metatarsal heads should be on the ground. The 2nd METatarsal is longer, the 3rd a little shorter, and the 4th and 5th even a little short than those. With the 1st MET shorter, these 5 form a kind of parabolic arc if you will. Each metatarsal head still should contact the ground and then each of those metatarsals should be further supported/anchored by their digits (toes) distally.  So the foot is actually more truly a HEXAPOD. Take the old TRIPOD theory we have always spoken about and extend a curved line beyond the forefoot bipod points (1st and 5th metatarsals) to incorporate contact points on the 2, 3 and 4th metatarsal heads. These metatarsals help to form the TRANSVERSE arch of the foot. It is this transverse arch that has given us the easily explainable foot TRIPOD because if a line is drawn between just the shorter 1st and 5th metatarsals, we do not see contact of the 2-4 metatarsal heads when we only look for pressure between these two bipod landmarks, but the obvious truth is that the 2-4 metatarsals are just longer and extend to the ground further out beyond this theoretical line drawn between the 1st and 5th MET heads.   

So, the foot is a HEXAPOD. Make no mistake about it. It is more stable than a tripod because there are more contact points inside the traditionally discussed foot tripod model. And frankly, the tripod theory is just a lie and just too fundamentally simple, unless you are an American 3 toed woodpecker.

Dr. Shawn Allen,     www.doctorallen.co

one of the gait guys

The Abductor Heel Twist: Look carefully, it is here in this video.

This should be a simple “piece it together” video case study for you all by this point. This young lad came into our office with left insertional achilles pain of two weeks duration after starting some middle distance running.

What do you see here ? It is evident on both the right and the left, but it is a little more obvious on the left and can be seen on the left when he is walking back toward the camera as well.  You should see rearfoot eversion, it is excessive, and a small rearfoot adductor twist. Meaning, the heel pivots medially towards the midline of his body.  Some sources (Michaud) call this an Abductory Twist, but the reference there is typically the forefoot.  Regardless, to help our patients, we sometimes refer to this is “cigarette butt” foot. It is like stepping on a lit cigarette to put it out via twisting/grinding it into the ground. 

So, now that you can see this, what causes it? 

The answer is broad but in this case he had a loss of ankle dorsiflexion range.  The ankle mortise clearly did not have enough of ankle rocker range during midstance so as that limitation was met, the heel raised up prematurely during the moments when the opposite leg is in full swing imparting an external rotation on the stance limb (hence the external foot spin (adducting heel/abducting foot……depending on your visual reference)). There is a bit more to it than that, but that will suffice for now because it is not the central focus of our lesson today.

What can cause this ? As we said, a broad range of things:

  • hallux limitus
  • flexion contracture of the knee (swelling, pain, joint replacement etc)
  • short calf-achilles complex
  • weak tib anterior and extensor toe muscles
  • Foot Baller’s ankle
  • limited/impaired hip extension
  • weak glute (minimizing hip extension range)
  • sway back (lower crossed syndrome-type biomechanics)
  • short quadriceps (similarly impairing hip extension)
  • flip flop excessive use (or any other motor strategy that imparts more flexor compartment dominance (read: calf-achilles, FDL)
  • excessive pronation
  • impaired foot tripod mechanics
  • etc

The point is that anything impairing TIMELY (the key word is timely) forward sagittal gait mechanics can, and very likely will, impair ankle rocker.  Even the wrong shoe choice can do this (ie. someone who suddenly drops from a 12 mm heel ramped shoe into a 0-4mm ramped heel shoe and who thus may not have earned the length of the calf-achilles complex as of yet).

The abductor-adductor twist phenomenon is not a normal visual gait observation. It is a softly seen, but screaming loud, pathologic gait motor pattern that must be recognized.  But, more importantly, the source of the problem must be found, confirmed and resolved.  In this fella’s case, he has some weakness of the tib anterior and extensor toe muscles that has lead to compensatory tightness of the calf complex. There was no impairment of the glutes or hip extension, as this was just 2 weeks old or so, but if left unaddressed much longer the CNS would have likely begun to dump out of hip extension and gluteal function to protect……another compensation pattern. Remember, ankle rocker and hip extension have a close eye on each other during gait.

Clinical pearl for the true gait geeks…… if you see someone with a vertically bouncy forefoot-type gait (you know, those people that bounce up and down the hallway at work or school) you can usually suspect impaired ankle rocker and if you look closely, you will usually see a quick abductor-adductor twist.

Shawn and Ivo

the gait guys