The Cheetah man, PART 2: “Bird Dog”, again.

In last week Wednesday’s blog post (link) we discussed the video of this man running amazingly on all 4 limbs at an incredible speed. He was doing it beautifully, most people would have fallen flat on their face after the first leap forward. 

As we discussed on that day, and these 2 screenshot photos will prove, there is ipsilateral interference between the foot and hand in this quadrupedal gait. This is diagonal quadrupedal locomotion (QL); the forward moving lower limb is impaired from further forward progression by the posting up (contact) hand of the same side.  However, in his case, there is such quick removal of the leading hand/limb that he can advance the ipsilateral foot/leg as far forward as he is able without impediment from the same side hand contact. 

As we mentioned in the Bird Dog post last week, (see photo of lady on yoga mat above) the contralateral upper limb will be in the opposite phase of the contralateral lower limb. ie when the left lower limb is in extension, the right upper limb will be in flexion (this is the classic Bird Dog position).

In last weeks blog post (see photos above), the opposite is clearly happening. One can see in the first photo that bird dog is clearly not helping to train a gait pattern, and that is ok, it has other values at times. Rather, in this first photo we see left hip extension and right shoulder extension, just as we see in the baby photo. This contradicts Bird Dog but this does support bipedal gait patterns.  Think about gait. Your right leg and left arm flex until about midstance, when they start to transition into extension; the left leg and right arm are doing the opposite. At no point are the arm and opposite leg opposing one another as in Bird Dog.

As Ivo would say , “if you look at it neurologically, it is a crossed extensor reflex.  It is very similar to a protective reflex called the “flexor reflex” or “flexor reflex afferent”.

The principles remain intact.

More critical thinking today. Hope you enjoyed.

Shawn and Ivo,

The gait guys

The Cheetah man: A new perspective on Cross Crawl and neurologic patterning.

A few months ago we wrote a piece about Uner Tan Syndrome.  Here was a key point from that blog post (blog post link) and it links beautifully to our most recent controversial blog post on the “Bird Dog” rehab exercise (link here):

[In the video presented in that blog post, and in our “Bird Dog” post photo] there is ipsilateral interference between the foot and hand in this quadrupedal gait. In this diagonal quadrupedal locomotion (QL) the forward moving lower limb is impaired from further forward progression by the posting up (contact) hand of the same side. This would not occur if the QL gait was non-diagonal (ie. unilateral), the forward progression of the lower limb would be met with same time forward progression of the upper limb, allowing a larger striding out of both limbs.  This would enable faster locomotion without increasing cadence (which would be the only way of speeding up in the diagonal QL), at the possible limitation of necessitating greater unilateral truncal postural control (which is a typical problem in some of these Uner Tan Syndrome individuals who typically have profound truncal ataxia).  

So, why are we showing you the video above today ?  If you do not know, go read those 2 blog posts again and look more closely at the video above. At exactly 0:21 seconds into the video, at the slow motion section, you can see what we were talking about in the Bird Dog post last week, that being that the quadrupedal pattern that is neurologically substantiated is that when the right lower limb is in flexion, so is the left upper limb. (we will show these 2 photos in tomorrows post).  Where as, “Bird Dog” shows the opposite, that the contralateral upper limb will be in the opposite phase of the contralateral lower limb.

Who cares right ?  Well, it matters.  In the video above, this could be a problem because if the right leg is in flexion that means that the right arm will be moving into extension. This means that the knee and the hand will be running into each other (look at the baby photo here). As we discussed in the Uner Tan article this will impair faster quadrupedal locomotion. It is also one of the theories as to what may have pushed us to become bipedal and allow faster ambulation (there are many theories of course).  So, how then does this guy in the video move like a cheetah ? How is he going so fast with the quadrupedal pattern we have clearly outlined here ?

Within days a blog reader (Micheal L, thanks Michael) messaged us and said this:

  • As a person who likes what’s going on at MoveNat, this type of quadrupedal movement is referred to by them as contralateral movement and is how they teach people to crawl at their seminars. In CrossFit workouts, we also do bear crawls as an exercise, and I always try to maintain a contralateral gait. i.e. Right arm moves forward as left foot comes forwards and vice versa. 
    So, in other words, in the Uner Tan Syndrome (UTS) the gait is cumbersome and inefficient. In the video above and at MoveNat seminars, it’s a technique/skill.
    Did you guys intend for this comparison, or am I out in the cornfield on this?
    Here was Dr. Uner Tan  himself chiming in on the dialogue:
  • Üner Tan It is not the same type of locomotion, i.e., not “the diagonal-sequence quadrupedal locomotion”, which is also used by non-human primates.. .
    Michael: The guy runs so fast it’s hard for me to see it well. Okay, so with UTS the lower limb runs into the upper limb. In this video, his upper limb quickly gets out of the way, giving room for the lower limb (to further flex forward increasing swing phase forward step length). It’s just really hard to see it without slow motion. Thank you for clarifying.

As we said in last weeks post on all of this:
“Think about gait. Your right leg and left arm flex until about midstance, when they start to extend; the left leg and right arm are doing the opposite. At no point are the arm and opposite leg opposing one another. 
If you look at it neurologically, it is a crossed extensor reflex.  It is very similar to a protective reflex called the “flexor reflex” or “flexor reflex afferent”. 

In this video case today, it appeared on the surface because of the speed of this fella, that all that we have been talking about had been left in the dust. But, after looking at things closer and more slowly, the principles remain intact.  For now.
Just a little open thinking digging today. Hope you enjoyed.
Shawn and Ivo,
The gait guys

This simple screening test becomes a form of exercise.

Last week we explored the “Lean” test to see how your QL and gluteus medius were paired. Today we look at a simple CNS screen for your “central pattern generators” or “CPG’s”. If you do not pass, then the exercise becomes the rehab exercise. If you (or your client) does not have good coordination between the upper and lower extremity, then they will not be that efficient, physiologically or metabolically.

The “cross crawl” or “step test” looks at upper and lower extremity coordination, rather than muscular strength. If performed for a few minutes, it becomes a test that can look at endurance as well.

It is based on the “crossed extensor” response, we looked at last week. That is, when one lower limb flexes, the other extends; the contralateral upper limb also flexes and the ipsilateral upper limb extends. It mimics the way things should move when walking or running.

  • Stand (or have your client stand) in a place where you will not run into anything.
  • Begin marching in place.
  • Observe for a few seconds. When you (or your client) are flexing the right thigh, the left arm should flex as well; then the left thigh and right arm. Are your (their) arms moving? Are they coordinated with the lower extremity?
  • What happens after a few minutes? Is motion good at 1st and then breaks down?
  • Now speed up. What happens? Is the movement smooth and coordinated? Choppy? Discoordinated?
  • now slow back down and try it with your (their) eyes closed

If  movement is smooth and coordinated, you (they) pass

If movement is choppy or discoordinated, there can be many causes, from simple (muscle not firing, injury) to complex (physical or physiological lesion in the CNS).

  • If movement is not smooth and coordinated, try doing the exercise for a few minutes a day. You can even start sitting down, if you (they) cannot perform it standing. If it improves, great; you were able to help “reprogram” the system. If not, then you (they) should seek out a qualified individual for some assistance and to get to the root of the problem.

The Gait Guys. Giving you information you can use and taking you a little deeper down the rabbit hole with each post.

A new twist on an old exercise

Do you know the the “Bird Dog” exercise? It looks like the picture above. The upper and contralateral lower extremities are extended, the the opposite ones are flexed. Seems to make make sense, unless you think about gait and neurology (yes, as you can see, those things seem to always be intertwined).

Think about gait. Your right leg and left arm flex until about midstance, when they start to extend; the left leg and right arm are doing the opposite. At no point are the arm and opposite leg opposing one another. Hmmm.

If you look at it neurologically, it is a crossed extensor reflex (see above); again, flexion of the lower extremity is paired with flexion of the opposite upper extremity. It is very similar to a protective reflex called the “flexor reflex” or “flexor reflex afferent”.

Wouldn’t it make more sense to do a cross crawl pattern? Or maybe like the babies shown above? Seems like if that’s the way the system was programmed, maybe we should try and emulate that. Don’t we want to send the appropriate messages to our nervous system for neurological re patterning? If you are doing the classic “opposite” pattern, what is your reasoning? Can you provide a sound neurological or physiological reason?

Think before you act. Know what you are doing.

The Gait Guys. Bridging the gap between neurology and gait, so you can do a better job.

The Hand Walkers, Part 2. Uner Tan Syndrome, the new research.

A year ago we wrote our first piece on Uner Tan Syndrome. We have always been interested in the neurodevelopmental windows of children and their process of moving through the various movement phases in the hopes of gaining clean upright bipedal gait. In our clinics daily we see many soft signs of sensory-motor pattern aberrancies that result in foot problems such as lack of pronatory control, or torsional long bone abnormalities and failures to protect frontal plane deviations (to name a very small few). In fact, these soft seonsory-motor signs and patterns can be found globally if one knows what to look for.  In our clinics we rarely see the serious neuro-developmental problems but Uner Tan Syndrome (UTS) has always been one of interest to us. We recently received a very kind email from Turkey, from Dr. Uner Tan himself, asking to reference some of our work so this was a serious honor.  The email sparked us to look into his research to look for newer work and we were happy to find it. Before we start into the new research findings, you will want to take a few minutes to read our last blog piece on Uner Tan Syndrome: The Hand Walkers.

This previous blog post discussed much of the research that was current at the time.  The following was from our previous blog post  on UTS  

UTS is a syndrome proposed by the Turkish evolutionary biologist Uner Tan. Persons affected by this syndrome walk with a quadrupedal locomotion and are afflicted with primitive speech, habitual quadrupedalism, impaired intelligence. Tan postulated that this is a plausible example of “backward evolution”. MRI brain scans showed changes in cerebellar development which you should know after a year of our blog reading means that balance and motor programming might be thus impaired.  PET scans showed a decreased glucose metabolic activity in the cerebellum, vermis and, to a lesser extent the cerebral cortex in the majority of the patients. All of the families assessed had consanguineous marriages in their lineage suggesting autosomal recessive transmission. The syndrome was genetically heterogeneous.  

However, some startling new research has recently surfaced and if most are paying attention, they will see the value in our 1000+ blog posts here at The Gait Guys but more so discover Dr. Tan’s most startling conclusion from the Frontiers in Neurology article below. We are currently moving through the most recent research so you will want to check in with us again soon for our follow up blog posts on this topic. 

Here was Dr. Tan’s et al abstract conclusion of his most recent research, and we think it is earth shattering.

Human quadrupedalism is not an epiphenomenon caused by neurodevelopmental malformation and ataxia.  

Two cases with quadrupedal locomotion (QL) were presented. In both cases, cognitive and psychiatric functions were normal and, no neurological deficits were observed, except for a sequel paralysis of left leg in Case 2. It was suggested that human QL (1) should not be considered as an epiphenomenon caused by neurodevelopmental malformation and ataxia, but (2) may be considered as a re-emergence of the ancestral diagonal QL, and (3) it may spontaneously emerge in humans with entirely normal brains, by taking advantage of neural networks such as central pattern generators that have been preserved for about 400 million years.

We will have more to come shortly, but for now, realizing that the human brain, even when normal, can take advantage of neural networks encompassing Central Pattern Generators (CPG’s) that have been suppressed for 400 million years is startling information in our opinion.

Check back in with us soon.

Shawn and Ivo, The gait guys


Front Neurol. 2012 Oct 25;3:154. doi: 10.3389/fneur.2012.00154. eCollection 2012. Karaca S1, Tan MTan U. Human quadrupedalism is not an epiphenomenon caused by neurodevelopmental malformation and ataxia.

Human Gait Changes following mastectomy. Taking Angelina Jolie’s news and putting it into gait context.

The Gait Guys are on the case looking at the effects of gait changes following mastectomy just a day after the news of Angelina Jolie’s double mastectomy.

Research has confirmed that following a mastectomy there are limitations in the efficiency of the upper limb and even changes in the posture of the torso. (1,2,3)

Following mastectomy, whether unilateral or bilateral, restorative measures are necessary. From a biomechanical perspective, obviously depending on breast size, removing a considerable mass of tissue is going to change the symmetry of the torso particularly if we are dealing with a unilateral mastectomy.  Not only is it going to change symmetry from a static postural perspective but it will change dynamic postural control, mobility and stability as well as dynamic spinal kinematics.  The literature has even shown that post-mastectomy clients display changes in spatiotemporal gait parameter such as step length and gait velocity.

Breast tissue moves. It oscillates a various cycles depending on speed of walking or running.  There is a rhythmic cycle that eventually sets up during walking and running and the cycle is intimately and ultimately tied to arm swing.  Thus, it would make sense that removing a sizable mass of tissue, particularly when done unilaterally, will change the tissue and joint rhythmicity. And if you have been here with The Gait Guys for more than a year you will know that impairing an arm swing will show altered biomechanics in the opposite lower limb (and furthermore, if you alter one lower limb, you begin a process of altering the biomechanical function and rhythmicity of the opposite leg as well.)  Here are 2 links for more on these topics, Arm Swing: Part 1 and Arm Swing: Part 2, When Phase is Lost. Plus here from our blog search archives, everything we have talked about on Arm Swing.

Arm swing impairment is a real issue and it is one that is typically far overlooked and misrepresented. We are currently working on several other blog posts for near future release including walking with a handbag/briefcase, walking with a shoulder bag, walking and running with an ipod or water bottle in one hand and even spinal symmetry changes from scoliosis that can either consciously or unconsciously alter arm swing and thus global body kinematics.  (We have also noted changes in opposite leg function secondary to a frozen shoulder (adhesive capsulitis) and we have that blog article in the works as well.)  The bottom line is that because of the neurologically embedded crossed extensor reflex and cross crawl response that permeates all human locomotion, anything that changes one of the limbs, whether it be a direct limb issue or something to do with the stabilization of the limb (as in this case the breast/chest wall), can and very likely will impair and change locomotion and motor pattern choices and programming.

Obviously the degree to which intervention is taken depends on the amount and location of breast tissue removed and intervention will be determined by physical placement of the prosthesis (whether it be external or internal) as well as the prosthesis weight, shape and possibly several other independent factors such as comparative support to the chest wall in comparison to the opposite breast. (In another future blog post we will address other methods of intervention such as latissimus dorsi relocation to reform the breast mass. This deserves a blog article all on its own because taking away a major shoulder, scapular and spinal stabilizer and prime mover has never made sense to us clinically or biomechanically.)

In Hojan’s study (below) they found significant differences in the gait parameters in the younger age groups with and without breast prosthesis however there appeared to be no significant differences in the women of the older study group.  However, it appeared that their study did not take into account all of the intimate issues we talk about in gait here on The Gait Guys blog. None the less, in the younger and likely more active study group, the use of a breast prosthesis brought the gait parameters closer to the healthy control group, as we suspected. 

Bottom line, every external and internal parameter that changes affects the human organism and thus affects their gait.

Again, here are those links to our other blog writings on arm swing that are paramount to understanding what we are discussing here today.

Arm Swing Part 1: The Basics

Arm Swing Part 2: When Phase is Lost

From our blog search

Shawn and Ivo, The Gait Guys

1.Blomqvist L, Stark B, Engler N, et al. Evaluation of arm and shoulder mobility and strength after modified radical mastectomy and radiother- apy. Acta Oncol. 2004;43(3):280Y283.

2. Rostkowska E, Bak M, Samborski W. Body posture in women after mastectomy and its changes as a result of rehabilitation. Adv Med Sci. 2006;51:287Y297.

3. Crosbie J, Kilbreath SL, Dylke E, et al. Effects of mastectomy on shoulder and spinal kinematics during bilateral upper-limb movement. Phys Ther. 2010;90(5):679Y692.

4. Hojan K, Manikowska F, Molinska-Glura M, Chen PJ, Jozwiak M. Cancer Nurs. 2013 Apr 29. [Epub ahead of print] The Impact of an External Breast Prosthesis on the Gait Parameters of Women After Mastectomy.

An Alternate View of Crawling and Quadrupedal Motor Patterns: A Correlation to Free Solo Mountain Climbers ?

Quadruped Patterns: Part 1

In the last 3 years, if you have been with us here at The Gait Guys that long, you will have read some articles where we discuss quadrupedal gait (link: Uner Tan Syndrome) and also heard us talk about CPG’s (Central Pattern Generators) which are neural networks that produce rhythmic patterned outputs without sensory feedback. You will have also read many of our articles on arm swing and how they are coordinated with the legs and opposite limb in a strategic fashion during gait and running gaits. Through these articles, we have also eluded to some of the fruitless aspects of focusing solely on retraining arm swing in runners because of the deep neurologic interconnectedness to the lower limbs and to the CPG’s. 
IF you are interested in any of these articles we have written please feel free to visit our blog and type in the appropriate words (Uner Tan Syndrome, arm swing, cerebellum, cross over gait) into the Search box on the blog.

Here we briefly look at interconnected arm and leg function in crawling mechanics in a high functioning human (as compared to the Uner Tan Syndrome) in arguably the best solo free climber in the world, Alex Honnold. Here we will talk about the possible neurologic differences in climbers such as Alex as compared to other quadruped species. Primarily, there is suspect of an existing shift in the central pattern generators because of the extraordinary demand on pseudo-quadrupedal gait of climbing because of the demand on the upper limbs and their motorneuron pools to mobilize the organism up the mountain. The interlimb coordination in climbing and crawling biomechanics shares similar features to other quadrupeds, both primate and non-primate, because of similarities in our central pattern generators (CPG’s). New research has however determined that the spaciotemportal patterns of spinal cord activity that  helps to mediate and coordinate arm and leg function both centrally, and on a cord mediated level, significantly differ between the quadruped and bipedal gaits. In correlation to climbers such as Alex however, we need to keep it mind that the quadrupedal demands of a climber (vertical) vastly differ in some respects to those of a non-vertical quadrupedal gait such as in primates and those with Uner Tan Syndrome. This is obvious to the observer not only in the difference in quadrupedal “push-pull” that a climber uses and the center-of-mass (COM) differences.  To be more specific, a climber keeps the COM within the 4 limbs and close to the same surface plane as the hands and feet (mountain) while a primate,  human or Uner Tan person will “tent up” the pelvis and spine from the surface of contact.

What some of the research has determined is that in quadrupeds the lower limbs displayed reduced orientation yet increased ranges of kinematic coordination in alternative patterns such as diagonal and lateral coordination.  This was clearly different to the typical kinematics that are employed in upright bipedal locomotion. Furthermore, in skilled mountain climbers, these lateral and diagonal patterns are clearly more developed than in study controls largely due to repeated challenges and subsequent adaptive changes to these lateral and diagonal patterns.  What this seems to suggest is that there is a different demand and tax on the CPG’s and cord mediated neuromechanics moving from bipedal to quadrupedal locomotion. There seemed to be both advantages and disadvantages to both locomotion styles. Moving towards a more upright bipedal style of locomotion shows an increase in the lower spine (sacral motor pool) activity because of the increased and different demands on the musculature however at the potential cost to losing some of the skills and advantages of the lateral and diagonal quadrupedal skills.  Naturally, different CPG reorganization is necessary moving towards bipedalism because of these different weight bearing demands on the lower limbs but also due to the change from weight bearing upper limbs to more mobile upper limbs free to not only optimize the speed of bipedalism but also to enable the function of carrying objects during locomotion.

The take home seems to suggest that gait retraining is necessary as is the development of proper early crawling and quadruped locomotor patterns. Both will tax different motor pools within the spine and thus different central pattern generators (CPG). A orchestration of both seems to possibly offer the highest rewards and thus not only should crawling be a part of rehab and training but so should forward, lateral and diagonal pattern quadrupedal movements, on varying inclines for optimal benefits.  Certainly we need to do more work on this topic, the research is out there, but correlating the quad and bipedal is limited. We will keep you posted. Next week we will follow up on this quadrupedal topic with a video that will blow your mind ! So stay tuned !

Shawn and Ivo
The Gait Guys

Scand J Med Sci Sports. 2011 Oct;21(5):688-99. Idiosyncratic control of the center of mass in expert climbers. Zampagni ML, Brigadoi S, Schena F, Tosi P, Ivanenko YP.

J Neurophysiol. 2012 Jan;107(1):114-25. Features of hand-foot crawling behavior in human adults. Maclellan MJ, Ivanenko YP, Cappellini G, Sylos Labini F, Lacquaniti F.