Gait and Climbing: Part 1

Lucid Dreaming is the name of a rock in the Buttermilks of Bishop, California. This is no ordinary rock. It is a V15. Summiting this rock is basically only 3 moves off of 3 holds, from your fingertips. The remainder of the climb is sliced bread. If you can do the 3, you can get to the top. The problem is, only a handful of people in the world can do it. How hard can this be, after all you start sitting down.

Strength, stability, mobility, endurance, skill, experience, movement patterns … . it is all here, today, on The Gait Guys blog.

Author: Dr. Shawn Allen

There are things that other people can do in life that rattle your brain. These are tasks that these individuals make look fairly simple, but in actuality are nearly impossible to the average person.  The honest fact is that many of us could do many of these things to a degree if we would dedicate a portion of our day to building the engine to perform these tasks, but the truth is that many of us would rather sit down and be entertained than get up and struggle.

Here on The Gait Guys blog, bipedal and quadrupedal gait has been discussed for over 5 years. Discussions have gone deep into the strange quadrupedal gait of Uner Tan Syndrome and have delved into the critical neurology behind CPG’s (Central Pattern Generators) which are neural networks that produce rhythmic patterned outputs. We have gone on and on about arm swing and how they are coordinated with the legs and opposite limb in a strategic fashion during walking running gaits.

Today I will look briefly at the interconnected arm and leg function in a high functioning human arguably one of the best new hot shots in climbing, Alex Megos. This year the German, as seen in this video link today, managed to summit Lucid Dreaming, a V15 in the Buttermilks of Bishop, California. Hell, you can say that this is just a big boulder, but there are not many V15s in the world like this one. Only a few of the very best in the world have even tried this rock, and you can count even fewer who have reached the summit. So, what does V15 mean to you? “virtually impossible” just about sums it up. Watch the video, this V15 starts from a “sit-start”, many folks wouldn’t even get their butts off the ground to complete the first move, that is how hard this is.  Watch the video, if this does not cramp your brain, you perhaps you don’t have one.

Are there possible neurologic differences in climbers such as Megos 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. We know these quadrupedal circuits exist. In 2005 Shapiro and Raichien wrote “the present work showed that human QL(quadrupedal locomotion) may spontaneously occur in humans with an unimpaired brain, probably using the ancestral locomotor networks for the diagonal sequence preserved for about the last 400 million years.”

As we all know, 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 Megos however, we need to keep in 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, in those with Uner Tan Syndrome and during our “bear crawl” challenges in our gyms. This should be obvious to the observer in the difference in quadrupedal “push-pull” that a climber uses and the center-of-mass (COM) differences.  To be more specific, a climber must reduce fall risk by attempting to keep the COM within the 4 limbs while remaining close to the same surface plane as the hands and feet (mountain) while a primate,  human or Uner Tan person will choose  to “tent up” the pelvis and spine from the surface of contact which narrows the spreading of the 4 contact points. Naturally, this “tenting up” can be reduced, but the exercise becomes infinitely more difficult, to the point that most cannot quadrupedally ambulate more than a very short distance. I will discuss this concept in Part 2 of this series on climbing.  If you study childhood development and crawling patterns, you need to be familiar with UTS (search our blog, save yourself the time), the flaws in the neurology behind the "Bird Dog” rehab pattern, and crawling mechanics … and of course, study climbers.

Some 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 progressive 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 I need to do more work on this topic, the research is out there, but correlating the quad and bipedal is limited. I will keep you posted. Be sure to read my 3 part series on Uner Tan Syndrome, here on The Gait Guys blog. Some of today’s blog is rehash of my older writings, naturally I am setting the stage for “Part 2″ of Climbing.

– Dr. Shawn Allen

 References:

Shapiro L. J., Raichien D. A. (2005). Lateral sequence walking in infant papio cynocephalus: implications for the evolution of diagonal sequence walking in primates. Am. J. Phys. Anthropol.126, 205–213 10.1002/ajpa.20049

Scand J Med Sci Sports. 2011 Oct;21(5):688-99. Idiosyncratic control of the center of mass in expert climbers. Zampagni ML , Brigadoi SSchena FTosi PIvanenko 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.

Spinal interneuronal networks linking the forelimbs and hindlimbs

Do the intimate relationships of the upper limbs and lower limbs suggest that quadrupedal skill sets, if not true quadrupedal gait, were a piece of our past locomotion strategies ?  Or is it just representative of the close linkages for gait efficiency? Or maybe both?

In this study below the researchers pondered whether lower limb motor function can be improved after a spinal cord lesion by re-engaging functional activity of the upper limbs. Although this study looked at spinal cord hemisections in adult rats we know there is likely human correlation. This study showed improved hindlimb function when the forelimbs were engaged simultaneously with the hindlimbs during treadmill step-training as opposed to training only the hindlimbs.
As we have proposed here on the gait guys blog many times previously, this study’s results provide strong evidence that actively engaging the forelimbs improves hindlimb function and that one likely mechanism underlying these effects is the reorganization and re-engagement of rostrocaudal spinal interneuronal networks.
“For the first time, we provide evidence that the spinal interneuronal networks linking the forelimbs and hindlimbs are amenable to a rehabilitation training paradigm. Identification of this phenomenon provides a strong rationale for proceeding toward preclinical studies for determining whether training paradigms involving upper arm training in concert with lower extremity training can enhance locomotor recovery after neurological damage.”

This likely has huge implications in rehab measures and gait retraining for those who are not spinal cord impaired as well.  We have discussed many times that making a single limb change merely because the observer/clinician does not like the functional appearance of a limb is a  mistake most of the time. That what we see is a compensation, not the problem.  Go back and review our many “arm swing” blog posts, you should recall that the arms can have a huge impact on the leg function and that many times the arms take their cues from the lower limbs during gait.  This is a topic we have hammered many times in many blog posts and in many courses we have taught.  It is nice to see the literature continue to support the close relationships of the 4 limbs on a neurologic level.

Brain. 2013 Nov;136(Pt 11):3362-77. doi: 10.1093/brain/awt265. Epub 2013 Oct 7.

Use of quadrupedal step training to re-engage spinal interneuronal networks and improve locomotor function after spinal cord injury.

Shah PK1, Garcia-Alias G, Choe J, Gad P, Gerasimenko Y, Tillakaratne N, Zhong H, Roy RR, Edgerton VR.

A theory for bipedal gait ? Ipsilateral interference between the foot and hand in quadrupedal gait.

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Human quadrupedalism is not an epiphenomenon caused by neurodevelopmental malformation and ataxia: Uner Tan Syndrome, Part 3

* Alert: Before you read this blog post you will do yourself a great degree of mental service by reading our 2 prior blog posts on this video.  There is an important learning progression here. Here are the links:

http://thegaitguys.tumblr.com/post/28332726553/the-hand-walkers-the-family-that-walks-on-all

http://thegaitguys.tumblr.com/post/78470419988/the-hand-walkers-part-2-uner-tan-syndrome-the

Note that in this video 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).  

As the video progresses one can see that bipedal locomotion IS IN FACT POSSIBLE in Uner Tan syndrome individuals. 

This is the excerpt from the embedded video:

“Two adult siblings from a consanguineous famiy in Kars, Turkey, exhibited Uner Tan syndrome with severe mental retardation, and no speech, but with some developmental differences.. 
There was no homozygocity in the genetic analysis, but the extremely low socio-economic status suggested epigenetic changes occurred during pre- and post-natal
development. 
Quadrupedal locomotion in cases with Uner Tan syndrome exhibit interference between the ipsilateral extremities, and this also occurred in all tetrapods with diagonal sequence QL since this form of locomotion appeared around 400 MYA. 
The ipsilateral limb interference might have been the triggering factor for bipedal locomotion in our ancestors, and walking upright would enhance their chances of survival, because of the benefits in the visual and manual domains. The ipsilateral interference theory is a novel theory for the evolution of bipedalism in human beings, and was first proposed by Uner Tan in 2014.”

As Karaca, Tan & Tan (1) discussed in their article:

“In discussions of the origins of the habitual QL observed in Uner Tan syndrome, it was argued that this quadrupedalism might be an epiphenomenon caused by neurodevelopmental malformation and severe truncal ataxia (Herz et al., 2008). The present work will show that this argument may be untenable, presenting two individuals with QL who do not exhibit ataxia, and who have entirely normal brain images and cognitive functions.”

As we mentioned in our last blog post,

“Tan and Ozcelik mentioned in their recent research, in UTS the obligate diagonal QL was associated with some genetic mutations and cerebellovermial hypoplasia, and was seen as an adaptive self-organizing response to limited balance. On the other  hand, the present work showed that human QL may spontaneously occur in humans with an unimpaired brain, probably using the ancestral locomotor networks for the diagonal sequence preserved for about the last 400 million years. (Shapiro and Raichien, 2005; Reilly et al., 2006).” (1)

Kind of brings some new “slap in the face” thoughts to the rehab “bird dog” exercise doesn’t it !  Driving a 400 million year old quadruped motor pattern (ya, ya, we know it is a early-window primitive cross crawl infant neurodevelopmental pattern, we have been to Pavel Kolar seminars. Don’t try to argue, just think past all this. Go get a beer or walk in the park and cogitate on this a bit, it is important.)

If you want to dive deeper into this kind of work,  you may want to go and look at some of our recent work on Arm Swing here. But don’t forget to watch this video above again and pay close attention to what we mentioned here.

We received this video on Monday (March 3, 2014) directly from Dr. Uner Tan himself in Turkey. We are very grateful for all that he has been sharing with us behind the scenes and we are grateful for his research and for this budding relationship.  Thank you Dr. Tan !  

Shawn and Ivo, The Gait Guys

Reference: 

1. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3480821/

Bipedal vs. Quadrupedal. A Navy Seal vs. Chimp

Next week we have a short series on quadrupedal gait. You won’t want to miss this one. We are gonna show you something that will freak you out ! But as always, we have lessons and teachings with it, important ones.  

Here is a primer.  Enjoy