Researchers at England’s Northumbria University analyzed the gait and oxygen uptake of 18 recreational and elite runners performing a series running tasks both barefoot and shod.Dr. Michael Wilkinson, lead researcher and avid barefoot runner determined the following in their study:- a significant saving in energy from taking off running shoes- mechanical differences in the foot strike patterns (shod runners did more heel strike, unshod were more midfoot striking)- there were immediate foot strike changes in previously shod  runners who suddenly changed to unshod foot strike- there is less oxygen use during barefoot running compared to running shod at the same speed. Hence improved running economy.Characteristically, skilled unshod runners have a distinctive running gait utilizing:- mid-foot landing- shorter stride lengths- faster stride rates- reduced ground contact time- lower impact force and loading rates which dampens injury inducing forces- reduced oxygen utilization. The 6% improvement in economy was the same as that previously reported after a nine-week training program for shoe-wearing runners, who also enjoyed a 3% improvement in running performance.Click on the link above for the Science article.

Is Barefoot more economical ?

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Forefoot Rocker and Premature Heel Rise:

 

Remember the rockers? We did a series on this a few weeks ago. 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. There are 4 things that SHOULD happen at this point to ensure the heel comes up :

 

1. continued forward momentum  of the body

2. the posterior compartment (primarily the gastroc/soleus group and tibilais posterior) contract to accelerate the rate of forward limb movement.

3. passive tension in the posterior compartment muscles

 the windlass effect of the plantar fascia (see diagram)

Watch this slow motion video and what do you see? You should see some midfoot collapse and premature heel rise, especially on the right foot. Did you notice the little “bounce” in his step? How about the subtle adduction of his heel, L > R?  Watch it again until you see it. (The bounce is generated by the premature heel lift and premature firing of the calf compartment muscles.  Normally the body mass is further forward of the heel rise event, and thus contraction of the calf generates a more forward directed vector, however, when the heel rise is premature the body mass is still somewhat over the foot.  Thus, if the calf were to fire at this moment, it would cause a vertical body mass movement vector.  When this occurs bilaterally these clients will have a very “bouncy” vertically oriented gait strategy.  This is very inefficient gait when it occurs. Plus there is a dramatic reduction in the pronation phase of gait, so shock absorption is severely reduced.)

Does he have forward progression of the body mass? Yes

Do you think the posterior compartment is actively contracting? Probably too much. Remember the medial gastrocnemius adducts the heel at the end of terminal stance to assist in supination.

Does there appear to be increased passive tension in the posterior compartment? Yes, it appears to be the case !

How is his windlass mechanism? Good but not good enough. (see our next blog post regarding the Windlass)

Premature heel rise… Coming to a midfoot overpronator and people with loss of hip extension near you.

Telling it like it is. We are the Gait guys…..

Time for a quick pedograph case:

This person presented with arch pain and occasional forefoot pain.

Note the increased size (length) of the heel print with blunting at the anterior most aspect. The midfoot impression is  increased, revealing collapsing medial longitudinal arches. The forefoot print has increased pressures over the 2nd metatarsal heads bilaterally, and the 1st on the left. She claws with toes 2-4 bilaterally.

This demonstrates poor intrinsic stability of the foot (as evidenced by the increased heel impression and midfoot collapse) and well as decreased ankle rocker (as evidenced by the increased forefoot pressures).

We also see increased ink under the distal second digit (esp on the right). This suggests some possible incompetence of the first ray complex and big toe, which is represented by the medial ink presentation under the great toe (suggesting a pinch callus, which is seen when there is spin of the foot and insufficient great toe anchoring and push off).  When the great toe function is compromised, we tend to see increased activity of the 2nd digit long flexors, represented well here by increased ink under the 2nd toe.

The pedograph truly does provide a window to the gait cycle!

We remain: Gait Geeks

Grab a Beer and Watch this Heel Strike Flick !

Wow, only one mid-forefoot striker in the whole bunch …….everyone else is a heavy heel striker. ……. and so the epidemic continues……… until this plague ends runners will always have injuries and guys like Ivo and myself will never be able to retire ! …….. until then…….. we remain dreamers of Boats, Beaches, Bars and Ballads (a great Jimmy Buffett box set !)

“Fins to the left, fins to the right, ….. We’re the only GAIT in town”

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Gait Cycle Basics: Part 3

As Promised: The Rockers…

According to Perry, progression of gait over the supporting foot depends on 3 functional rockers

heel rocker: the heel is the fulcrum as the foot rolls into plantar flexion. The pretibial muscles eccentrically contract to decelerate the foot drop and pull the tibia forward

 

ankle rocker: the ankle is the fulcrum and the tibia rolls forward due to forward momentum. The soleus eccentrically contracts to decelerate the forward progression of the tibia over the talus. Ankle and forefoot rocker can be compromised by imbalances in strength and length of the gastroc/soleus group and anterior compartment muscles.

 

forefoot rocker: tibial progression continues and the gastroc/soleus groups contract to decelerate the rate of forward limb movement. This, along with forward momentum, passive tension in the posterior compartment muscles, active contraction of the posterior compartment and windlass effect of the plantar fascia results in heel lift.

Now see if you can pick out the rockers in today’s video.

The Gait Guys… We are everywhere!!

There are 2 photos here (move your cursor over to the little triangle on the right to highlight the bar to toggle between photos)

Can you believe that an experienced runner would let a pair of shoes get this far on both sides.  This person does a few marathons a year and has been a patient of our for years…..he tends to milk out every last step in a pair of shoes but we had to hog-tie him and flog him repeatedly for going overboard this time. I bet there had to be 2000 miles on these puppies !  And get this…..he had no foot or knee pain ! (his response was, i saw the wear but i was not having any issues).

Can you imagine how far out side the contact line the knees had to be ? This has the old Nike Cesium beat by a long shot (they were rear foot posted varus by about 3degrees). Heck, this could be 20-25degrees varus !  There is no question that he is avoiding and rear or mid foot pronation……the dude is fixed in supination. 

OF clinical note, he has a fixed right hallux limtus (turf toe) so this likely helps him to avoid medial toe off and forcing dorsiflexion through the big toe joint……however, there are better strategies than this to avoid a hearty toe off !

It is amazing what the body can endure !  Take this as a lesson of what NOT TO DO !  keep the miles between 400-500 miles gang……there are only so many compression cycles in EVA foam before deformation occurs.  In this case there was both deformation and just pure and simple friction wear !

PS: this was an easy pick up clinically……he sat in the waiting room with the 55 gallon barrel set beside him ….the one that he had been carrying around between his knees to force this much rear foot varus !

Clinical Video Case Study: Tibial Varum with added Post-op ACL complications.

This is a case of ours. This young man had a left total knee reconstruction (Left ACL and posterolateral compartment reconstruction; allograft ligaments for both areas). This video is roughly 3 months post surgery.

Q: What anatomical variants are seen in this individual?

A: Note the genu and tibial varum present. This results in an increased amount of pronation necessary (right greater than left, because of an apparent Left sided short leg length;

* NOTE: post-operatively at this point the client had still some loss of terminal left knee extension. thus the knee was in relative flexion and we know that a slightly flexed knee appears to be a shorter leg. Go ahead, stand and bend your left knee a few degrees, the body will present itself as a shorter leg on that left side with all the body compensations to follow such as right lateral hip shift and left upper torso shift to compensate to that pelvic compensation.)

Normally, in this type of scenario (although we have corrected much of it at this point by giving him more anterior compartment strength and strategy as evidenced by his accentuated toe extension and ankle dorsiflexion strategies, these are conscious strategies at this point for the patient), the functionally shorter left leg has a body mass acceleration down onto it off of the longer right leg stance phase of gait. This sagittal (forward) acceleration is met by a longer stride on the right with an abrupt heel strike (in other words, the client is moving faster than normal across the left stance phase so there is abrupt and delayed heel strike on the right because of a step length increase. (again, this is just commentary, had we videoed this client weeks before this, you would have seen these gait pathologies. This video shows him ~70% through a gait corrective phase with us.)

Again, this client has bilateral tibial varum. You can see this as evidence due to the increased calcaneal valgus (ie. rearfoot pronation; look at the achilles valgus presentation).
He increases his arm swing on the Left to help bring the longer Right lower extremity (relative) through.
if you look closely you can also see early right heel departure which is driven by the increased forward momentum of the body off of the short left limb. In other words, the body mass is moving forward faster than normal onto the right limb (because of the abbreviated time spend on the left “short” leg) and thus the forward propulsed body is pulling the right heel up early and the heel is spinning inwards creating a net external rotation on the right limb (look for the right foot to spin outwards/externally ever so slightly in the second half of the video).

Early heel departure means early mid and forefoot weight bearing challenges and thus reduced time to cope well with pronation challenges. As we see in this case where the right foot is pronating more heavily than the left. You can think of it this way as well, the brain will try to make a shorter leg longer by supinating the foot to raise the arch, and the longer leg will try to shorten by creating more arch collapse/pronation.