The Bouncy Gait: Premature heel rise gait. Taking another look.

This is a great video example of a premature heel rise during gait. You should be able to clearly see it on the left foot (and this was toned down after we brought it to his awareness!).  The heel rise occurs early in the stance phase of gait, instead of the late stance phase.

We have talked about this bouncy type vertically oriented gait many times in blog posts and in our podcasts.  This is a pretty prevalent problem in the world, mostly because so many people have impaired ankle rocker/dorsiflexion from weak anterior compartments and short/tight posterior compartments.  None the less, for the majority, this is a pathologic gait pattern and it will impart undue stress into the posterior mechanism (calf-achilles complex). Just think about it, this person is going vertical at or prior to the tibia achieving 90degrees (perpendicular to the ground) instead of continuing to progress the tibia to 110+ degrees to enable normal timely pronation and foot biomechanical events.  This is not a normal gait. Period. This will change the function of the entire posterior chain upward. 

If you want to see another great example  from the frontal plane, check out this cute video representation of a vertial/premature heel rise bouncy gait. 

This gait style is caused by a premature heel rise from joint range limitation and/or from premature engagement of the gastrosoleus (and sometimes even the long toe flexors, you will see them hammering and curled in many folks). It can be a learned habitual pattern and nothing more, we have even seen it even in child-parental gait modeling in our offices. These people will never get to NORMAL full late-midstance of gait (without biomechanical compromise) and thus never achieve full hip extension nor adequate ankle dorsiflexion / ankle rocker. The gait cycle is an orchestrated symphony of timely events and when one or several timely events are omitted or impaired the mechanics are passed into other areas for compensation. This vertical gait style is very inefficient in that the gluteals cannot adequately power into hip extension into a forward progression drive, because the calf is prematurely generating vertical movement through ankle plantarflexion.  This strategy is sometimes deployed because the person actually is significantly ankle dorsiflexion (ankle rocker) deficient.  Meaning, they hit the limitations of dorisflexion and in order to progress forward they first have to go vertical.  This vertical motion, because they are moving into ankle plantarflexion, re-buys more ankle dorsiflexion range which then can be used if they so choose. Obviously, the remedy is to find the functional deficit, remove it and retrain the pattern.  There are a whole host of other problems that go with this compensation pattern but we wanted our mission to stay focused today.  Remember, this is usually a subconscious motor pattern compensation. Is it like the toe walking issue we talked about last week (post link here) ? It is similar in some ways and can have primitive and postural motor pattern implications. We will follow up the “Idiopathy Toe Walking Gait: Part 2” shortly but we wanted to strategically put this blog post ahead of it, because there are similar characteristics and implications. Trust us, there is a method to our madness 🙂

Shawn and Ivo

The Gait Guys

Vertical Oscilations, Danny Abshire and Running & Walking

https://www.facebook.com/photo.php?v=575995729092248&set=vb.111772995514526&type=2&theater

We saw this short 1 minute video by Danny Abshire on vertical movements in running (link is above). Here was the caption placed (by Runner’s Soul) with the video.

  • “Danny Abshire, running guru and CTO of Newton Running, explains how vertical oscillation can impede any runner’s performance – did you know that lifting 6 inches with every foot strike can add almost 2.5 miles onto a marathon?”

We are currently trying to find the reference material he used (anyone please forward it to us at thegaitguys@gmail.com).  In theory it makes sense.  Here is an article that shows something a little different. This research article shows shows that minimizing the center of mass vertical movement increases metabolic cost because of the loss of passive mechanical energy from pendulum mechanics. Now, to be fair, apparently Danny was talking about increased distance and not metabolic cost. But what if distance was trumped by energy and time ?  Now there is a neat thought ! We doubt any marathoner would be upset if they ran further than the actual marathon distance but PR’d in the attempt.  One could easily postulate that the term “increased metabolic cost” would mean a slower run time because of the activity being inefficient.

  • This study’s findings findings clearly demonstrate that human walkers consume substantially more metabolic energy when they minimize vertical motion.

In this study’s case, it refers to walking, however could it postulate to running as well?  Just something to think about.  As our reading on this topic continues, and as we find supportive and conflicting journal information we will post attachments here amongst our other articles to make sure our readership can see both sides of the peer reviewed research. In Danny’s, and everyone defense, we often find conflicting research in peer reviewed articles, it almost seems at though one can take a stance on any side of a medical topic and find an article to prove the theory, sadly often leaving us nowhere but spinning in place.

Anyhow, the summary of this peer reviewed article by Ortega concluded that :

“in flat-trajectory walking, subjects reduced center of mass vertical displacement by an average of 69% but consumed approximately twice as much metabolic energy over a range of speeds . In flat-trajectory walking, passive pendulum-like mechanical energy exchange provided only a small portion of the energy required to accelerate the center of mass because gravitational potential energy fluctuated minimally. Thus, despite the smaller vertical movements in flat-trajectory walking, the net external mechanical work needed to move the center of mass was similar in both types of walking. Subjects walked with more flexed stance limbs in flat-trajectory walking, and the resultant increase in stance limb force generation likely helped cause the doubling in metabolic cost compared with normal walking. Regardless of the cause, these findings clearly demonstrate that human walkers consume substantially more metabolic energy when they minimize vertical motion.”

In our summarizing of the article it indicated that more vertical motion seems to engage some of the energy conserving pendulum effects of the limbs. We know this happens in the spine. Serge Gracovetsky (“the Spinal Engine”) and many other researchers have discussed this energy conservation by the repetitive coiling and uncoiling of the spinal curves and loading/unloading of the spinal discs.   Here is the journal and abstract below.

Shawn and Ivo, The Gait Guys

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J Appl Physiol. 2005 Dec;99(6):2099-107. Epub 2005 Jul 28. Minimizing center of mass vertical movement increases metabolic cost in walking. Ortega JD, Farley CT. Source

Locomotion Laboratory, Dept. of Integrative Physiology, University of Colorado, Boulder, CO 80309-0354, USA. ortegajd@colorado.edu

Abstract

A human walker vaults up and over each stance limb like an inverted pendulum. This similarity suggests that the vertical motion of a walker’s center of mass reduces metabolic cost by providing a mechanism for pendulum-like mechanical energy exchange. Alternatively, some researchers have hypothesized that minimizing vertical movements of the center of mass during walking minimizes the metabolic cost, and this view remains prevalent in clinical gait analysis. We examined the relationship between vertical movement and metabolic cost by having human subjects walk normally and with minimal center of mass vertical movement (“flat-trajectory walking”). In flat-trajectory walking, subjects reduced center of mass vertical displacement by an average of 69% (P = 0.0001) but consumed approximately twice as much metabolic energy over a range of speeds (0.7-1.8 m/s) (P = 0.0001). In flat-trajectory walking, passive pendulum-like mechanical energy exchange provided only a small portion of the energy required to accelerate the center of mass because gravitational potential energy fluctuated minimally. Thus, despite the smaller vertical movements in flat-trajectory walking, the net external mechanical work needed to move the center of mass was similar in both types of walking (P = 0.73). Subjects walked with more flexed stance limbs in flat-trajectory walking (P < 0.001), and the resultant increase in stance limb force generation likely helped cause the doubling in metabolic cost compared with normal walking. Regardless of the cause, these findings clearly demonstrate that human walkers consume substantially more metabolic energy when they minimize vertical motion.

Gait: Does Minimizing center of mass vertical movement change your metabolic cost ?

Research article: Minimizing center of mass vertical movement increases metabolic cost in walking.

Ortega JD, Farley CT. Locomotion Laboratory, Dept. of Integrative Physiology, University of Colorado, Boulder, CO 80309-0354, USA. ortegajd@colorado.edu

J Appl Physiol. 2005 Dec;99(6):2099-107. Epub 2005 Jul 28.

So what is this article’s bottom line ? The premise of the research article was to look at the relationship between vertical movement in gait and its metabolic cost by having human subjects walk normally and with minimal center of mass vertical movement (“flat-trajectory walking”). What the article found was that it costs more to move with a flat trajectory. In other words, dampening the normal vertical oscillations is not a good thing.  But we have some concerns.

Not that we have a major problem with this study, but we do have two concerns we think should have been brought up problem.

1- Were these folks in the study assessed for biomechanical compensations ? You have read our discussions on impaired ankle rocker. And one of the major flaws of impaired ankle rocker is the premature heel rise gait, where the person can adopt a rather boucey vertical gait, almost appearing to walk on the ball of their foot. These folks have a very vertical gait.

2- Since the study concluded that the less vertical trajectory gait was seen to be far less metabolically efficient it is a well founded question to ask more about the strategy they employed. In the study they merely added more joint flexion to dampen the vertical trajectory.  But, had they been coached to use the core to minimize vertical trajectory and utilize the energy moving forward while still obtaining some of the normal biomechanical components, some of which take advantage of limb extension, would the study have found the same thing ?  Once again we find a good study but one that bodes more questions than it answers, such as, did the researchers really know enough about gait biomechanics to give good cues?  Furthermore, how much vertical is too much ? How much dampening is too much ?

  We still appreciate the study and its findings, but you cannot trust everything you read, at least not without reading the fine print.  Here is the full abstract below. Read it yourself and if you are curious enough, get the full study for yourself.

Shawn and Ivo…….keeping you on the edge of the research.

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Journal Abstract

A human walker vaults up and over each stance limb like an inverted pendulum. This similarity suggests that the vertical motion of a walker’s center of mass reduces metabolic cost by providing a mechanism for pendulum-like mechanical energy exchange. Alternatively, some researchers have hypothesized that minimizing vertical movements of the center of mass during walking minimizes the metabolic cost, and this view remains prevalent in clinical gait analysis. We examined the relationship between vertical movement and metabolic cost by having human subjects walk normally and with minimal center of mass vertical movement (“flat-trajectory walking”). In flat-trajectory walking, subjects reduced center of mass vertical displacement by an average of 69% (P = 0.0001) but consumed approximately twice as much metabolic energy over a range of speeds (0.7-1.8 m/s) (P = 0.0001). In flat-trajectory walking, passive pendulum-like mechanical energy exchange provided only a small portion of the energy required to accelerate the center of mass because gravitational potential energy fluctuated minimally. Thus, despite the smaller vertical movements in flat-trajectory walking, the net external mechanical work needed to move the center of mass was similar in both types of walking (P = 0.73). Subjects walked with more flexed stance limbs in flat-trajectory walking (P < 0.001), and the resultant increase in stance limb force generation likely helped cause the doubling in metabolic cost compared with normal walking. Regardless of the cause, these findings clearly demonstrate that human walkers consume substantially more metabolic energy when they minimize vertical motion.

Gait: Does Minimizing center of mass vertical movement change your metabolic cost ?

The Gait Guys at the Movies: Terminator 2.  Here is a spot we did for Natural Running Centers………fun stuff, good data. We hope to offer a more technical version soon, with more details but for now……..Enjoy

The Gait Guys at the Movies: Terminator 2

The Dumpling Walk !

Its time for Gait Guys Gait Gaffs again ! 

This is one of our all time favorite gait styles. Aside from the atonic arm swing, what we love about this one is the vertical nature of this gait style.  If you look around you will see this one often. These are the bouncy folks.  There is a bucket load of vertical body movement when in fact the head should stay static in gait and in running.

This gait style is caused by a premature heel rise from premature engagement of the gastrosoleus (and sometimes even the long toe flexors, you will see them hammering and curled). The person will never get to full late-midstance of gait and thus never achieve full hip extension nor adequate ankle dorsiflexion / ankle rocker. These are timely events and specific things are supposed to happen during these phases of gait that are omitted and thus passed into other areas for compensation. This gait style is very inefficient in that the gluteals cannot power into hip extension into a forward progression drive, because the calf is prematurely generating vertical movement through ankle plantarflexion.  This strategy is sometimes deployed because the person actually is significantly ankle dorsiflexion (ankle rocker) deficient.  Meaning, they hit the limitations of dorisflexion and in order to progress forward they first have to go vertical. Obviously, the remedy is to find the functional deficit, remove it and retrain the pattern.  We will be going over this pattern quite a bit in our new DVD line when we can get to it, because there are other deficits that could drive this one such as short hip flexors and quads to name one. 

See you again on Gait Guys Gait Gaffs !…….Shawn and Ivo, we are…….The Gait Guys