Bipedalism (walking upright on two limbs) in hominids is considered a logical and efficient means of locomotion arrived at via hundreds of millions of years of evolution. At the newly instituted PLOS group of blogs a thorough post appearing on the newly moved blog Neuroanthropology describes Turkish individuals who are quadripedal and exhibit what is called Uner Tan Syndrome (UTS). There is some conjecture on the cause of this condition and on whether or not it is evolutionary atavism.

Human Quadrupeds

This syndrome was first discovered in 2005 by Üner Tan of Cukurova University in Turkey who is also a member of the Turkish Academy of Sciences.

I note that the quadripedal humans seem to be scurrying along at a fair clip. They are not wearing any coverings on their hands. From the photo it is difficult to determine what they wear on their feet. The video below does show some foot gear. At least some of the quadrupedal humans seem to have the forelimb contact on the heel of the hand, but others may contact further foreward.  I’m sure this will be looked at closer. Evolutionary analysis and better coaching may lead to improved 4 limb locomotion for these individuals. So far I have not come across any reports of any quadrupedal long distance endurance events.

This does appear to be a real syndrome however and the blog describes the symptoms and results of MRI and PET scans on subjects. The findings include:

“signs of cerebellar dysfunction including: intention tremor, dysdiadochokinesis (inability to execute rapidly alternating movements particularly of the limbs), dysmetria (lack of coordination of movement typified by under- or over-shooting the intended position), and nystagmus (involuntary rhythmic eye movement, with the eyes moving quickly in one direction, and then slowly in the other). However, the cerebellar signs are relatively mild, and they are no more pronounced in the quadrupeds than in the one affected brother who walks bipedally.”

My take on this is that the syndrome appears to be an inherited motor and sensory issue (HMSN). There are many disorders in this category with a variety of symptoms. Some of the more common ones include Refsum’s syndrome and Charcot-Marie-Tooth disease .

Both a BBC and PBS Nova documentary have been produced on this condition.

Links:

Neuroanthropology Blog Post on “Human Quadrupeds” by Greg Downs – thorough discussion, many reference links

John Hawks Discussion on “Turkish Tetrapods” in 2006

A New Syndrome With Quadripedal Gait Tan, U. Int J Neurosci. 2006 Mar;116(3):361-9.

Family That Walks on all 4s (NOVA show)

The Muppets on Early Gait Development

Ambling Along With 4.5 Million Year Old Flat Feet

A hominid species predating Lucy, (Australopithecus africanus) has been more fully described. Journalists have had first crack at the issue of Science in which the updated description of the species,  Ardipithecus ramidus (from 4.5 million years ago), appears. The rest of us could only see this issue late in the day.  The recently studied Ardipithecus specimens include the feet, which were clearly missing on Lucy (from 3.2 million years ago), but present among a limited set of other Australopithecus specimens. Ardipithecus was originally discovered in 1994 in Ethiopia.

The treasure trove of the day are the eleven fresh papers detailing  Ardipithecus and it’s (with a delay in publication for years) environment including botanical and other specimens found locally, the anatomy, and evolutionary conjectures all published in Science magazine. Details on excavation, locale, personnel, CT scans, three-dimensional reconstruction, dimensions and sizes of the specimens, were included in this comprehensive set of articles.

Ardipithecus was thought to live and spend time in trees, but would carefully climb rather than swing from the branches. Ardipithecus was also believed to spend time foraging for food, primarily plant based, on the ground while moving in a bipedal manner. Australopithecus was not a runner, nor is it likely with feet less well adapted  was Ardipithecus. Among other lower extremity differences between Homo erectus and Ardipithecus were flatter feet and an opposable big toe (metatarsus primus varus – actually  metatarsus primus adductus – a large angle in stance between the first and second metatarsal bones – but I’ll have to check out more photos and study the  articles in detail in Science magazine). If Ardipithecus twiddled her thumbs she could likely also twiddle her opposable big toes. Speaking of toes, one of the changes that is thought to make running possible for the later hominids was a shortening of the length of toes, in addition to an increase in arch height, and a host of other biomechanical changes.

An opposable big toe with a non-functional first ray makes for a decidedly different bipedal gait than even Lucy had. The tight grouping of the cuneiforms present in later hominids allowed the first ray to function effectively in weight transfer and propulsion rather than the little it could do as an opposable digit without stability in ground based bipedal gait. Of course a humanoid great toe does not offer much assistance in the trees. An important feature to note is that Ardipithecus did not knuckle walk, as can be determined from the wrist and hand structure, during bipedal gait, although the upper extremities were long. Nor did Ardipithecus appear to brachiate or swing through the tree branches.

Below are images of the upcoming cover of Science magazine with Ardipithecus on the cover and an image of Lucy missing her feet.

Update: Freely available articles at Science

Ardipithecus

Lucy on The Ground with no Toes

Related Articles

Movement and Exercise Spurred Evolutionary Brain Development

In The Beginning: We Were Made To Stand Upright

Walk This Way (Early Foot Prints  of Homo erectus)

Additional References:

Bonus Music: Ventures – “Walk Don’t Run” – Primitive filming (B&W)

Recent Evolution of Walk Don’t Run

Sense and Sensibility

Note: There are several comments, but the interface on word press blogs will only show them if you click on the title and view only this blog entry.

The media seems to have decided that barefoot running is the trend that can’t be stopped, and should perhaps be encouraged. “Throw away your shoes” seems to be the dominant theme, if not the only thing we hear. And no one wants to stand against the tide and seek balance.  I’ve run barefoot on the beach for miles, and enjoyed it. And I’ve done that for years starting in middle school. During high school, I enjoyed barefoot running along the beach during the run up to soccer season. And, even at that time professional football teams were said to do the same. But the current persistent hyping of barefoot is as balanced as are the discussions on health care reform. Some years back, HMOs were touted as the solution to all of our health care needs. But, they aren’t singing that tune any more.

Now we are told that we evolved to run barefoot. Shoes are tiny coffins for feet and have stopped evolution. Tiny coffins that stopped evolution? Really? Evolved to run barefoot? Well, yes we did evolve to run barefoot. But we’ve had 30,000 years to develop body coverings and improved aids to motion, comfort and speed. We’ve made shoes – one shoe fits either foot, domesticated horses (and even tamed elephants) to catch  a ride, added lifts to our sandals to move faster in battle (Caesar), made steam and coal powered engines for trains, boats, sailboats, steam boats, shoes – designed for right or left foot, made cars, bicycles, airplanes and rocket ships that have carried us to the moon.

We’ve gone from eating nuts and greens to meat and back to nuts and greens. We’ve made other aids like glasses, robot flown drones, satellites to explore the rest of the solar system. But wait, did we evolve for this? Or is it wrong? Should we be barefoot and living in trees or in caves? Could we run faster without shoes?

It is said that shoes don’t help prevent injuries. But does running barefoot? Does wearing “unbalanced” shoes help? Do those shoes help you burn more calories? One person’s opinion quoted in the NY Times was that they did, they made her legs sore, so they must burn more calories. To me, that just shows that she overdid it and was a victim of the “terrible too’s” – too far, too fast, too soon, (too often and too little rest).

Could we run faster without shoes? Since 1960, only at the Mexico City Olympics,  has the Olympic marathon been won as slowly as Abebe Bikila ran it while winning in Rome in what was a world record time in 1960 (2:15:16, an impressive time). In 1964, Bikila wore (Puma running) shoes in Tokyo, ran faster, and set another world record. He took 3 minutes off of his previous world record, running 2:12:11. The current world record of 2:03:59 is held by Haile Gebrselassie, who does wear shoes while racing. Of course the shoes the elite runners wear during races are usually racing flats. During training, there will be some variety, and some elite runners incorporate barefoot drills into their regimen.

Running barefoot should strengthen the intrinsic muscles of the foot. Those are the muscles that start in the foot and end in the foot. It could also have a strengthening effect on muscles in the leg. And for those who do need more support, it could have these muscles working harder than they should and not feel very good. Running barefoot or with minimalist shoes helps balance and joint position sense. Over cushioned shoes are distinctly bad for joint position sense (proprioception).  So yes, running shoes can cause many problems through bad fit, bad design, mismatch of foot to shoe, and in many other ways. That has been the subject of many lectures and articles. Unfortunately, there no longer seems to be a balance in approach to shoes versus barefoot, when it should be shoes and barefoot.

Looking at 30,000 (ya) year old to 2 (mya) million year old bones will tell you where we’ve been, but won’t tell you where we are as a species now. Wired magazine had a recent article quoting a renowned anthropologist who felt that running barefoot was the way to go, and that evolution would have taken care of plantar fasciitis and runner’s knee. Unfortunately, that may be a nice hypothesis, but we are all built differently and have different needs. Some are knock kneed, some are bow legged, some legs are just right. Some people have high arches, some have low, and some are just right. Some of us have 20/15 vision and can fly jets, others could run barefoot and naked in the sun without sunscreen and never get a melanoma, but that is not wise for most of us. Some can run a marathon in 2:05, others in 3:05 or 5:05, but there are vast differences between them.

In evolution there are many expressions of genes called “phenotypes”. There is no one size fits all. Regarding melanoma, skin color and vitamin D, an excellent example of evolution is apparent. With Africa the presumed origin of the genus homo, migration from Africa led to genetic (genotype) changes in the genes that affected melanin. Putting it simply, the northerners had a mutation that led to less melanin in the skin and a lighter mutation. This allowed for better absorption of UV and production of Vitamin D in the northern climes (less light, less intense solar impact). It is another example of differences through evolution and adaptation to the environment with survival of those best suited to the environment.

While some wonder if human evolution has stopped, many believe it continues in many ways. Social relations, altruism, tribalism, and many things have deep roots, but also morph and change. There are differences between us and among us. We all aren’t prepared to comfortably run barefoot. But some of us are. Those who are and those who want to should start slowly with a few minutes and gradually build on that. Don’t look at it as necessarily a cure all for everything. It will feel great for some, and not so great for others. It may solve some problems in some, it may create problems or not solve problems in others. So, no, I am not claiming that barefoot is all good, all the time, for everyone. And I’m not claiming that barefoot is awful,  bad for everyone, something for everyone to avoid, always. (There is no simple answer, there are few informative studies. But, to quote Leigh Peele with her classic and often used statement “it depends“).

On the subject of barefoot running, my views have evolved. My first interview on this topic was with a journalist who wanted everything black and white and refused to accept the possibility that in my opinion some may have a foot better designed for barefoot running than others. There was a refusal to accept that while I didn’t think barefoot was all good, I didn’t think it was all bad. The quotes used in that article didn’t reflect a nuanced approach but were couched as a warning not to run barefoot. This was not what I felt was correct for all. Not long after that another journalist got it right. I pointed the second journalist to the same barefoot subject pictured in the first article. The runner was shown with beautiful “C” shaped, mud covered feet after completing his first marathon barefoot. She wrote about it in the Orlando Sentinel, along with suggestions on how to start barefoot running. (The Philadelphia Inquirer and Washington Post within the past few months had recent quotes on starting barefoot running slow and easy and a little at a time in the context of a review of “Born To Run”.)

But, as we look at the one size fits all solution, we see a trend in approaches to a variety of injuries. While many years ago, people were told to stop running, they then were told that almost all injuries came from foot problems. Now it is core weakness. No one solution fits all problems. Each problem is really solved only by a “total approach” that looks at the injury in a multi-faceted way, and looks for what changes can be made in training, equipment, muscle imbalances, stretching and strengthening. One “fix” is not enough to get it right.

Insulin is a nice medicine. We don’t all need to inject it though. L-Dopa is good for Parkinsons, but we all don’t need to take it as a supplement.  Prozac is helpful for many, running does it for others. One size doesn’t fit all, nor does one solution.

NY Times Article

Best quote:

“In 95 percent of the population or higher, running barefoot will land you in my office,” said Dr. Lewis G. Maharam, medical director for the New York Road Runners, the group that organizes the New York City Marathon. “A very small number of people are biomechanically perfect,” he said, so most need some sort of supportive or corrective footwear.”

Pithy quote:

“The shoe arguably got in the way of evolution,” said Galahad Clark, a seventh-generation shoemaker and chief executive of the shoemaker Terra Plana, based in London. “They’re like little foot coffins that stopped the foot from working the way it’s supposed to work.”

Related Posts:

Comments on Chris McDougall’s fine book at http://www.drpribut.com/blog/?p=325

Bipedal Beginnings: http://www.drpribut.com/blog/?p=331

Evolution and Exercise: What Made the Brain Get Bigger: http://www.drpribut.com/blog/?p=368

Walk This Way: Oldest Bare Footprints – 1.5+ Million Years Old: http://www.drpribut.com/blog/?p=215

For more information and to visit a community forum I recommend the Runner’s World Barefoot Runners Forum with links and discussions on all things barefoot.

Music: Barefoot by Ray Collins Hot Club

To view comments please click on the title of this entry. There are several comments, but we are currently having some interface issues. For more discussion visit the active Runner’s World Forum linked to above.

Stimulating Brain Development: Evolution Of The Brain Spurred By Movement (a speculative hypothesis)

We previously mentioned the early hominid development of upright, obligatory, habitual bipedal posture mentioning the richer protein and calorie dense food which may have enabled better brain development. We’ll expand on that a bit with a “big think” and take it down a slightly different road. And we can have a bit of fun with a speculative hypothesis.

My thought (and hypothesis) is that exercise, viewed as aerobic movement, was the spur to development of a larger brain as is found in later hominids and modern humans. Tool making, enhanced socialization, all other more modern features and the larger cortex itself derive from motion, movement, and the positive effect that “exercise” has on the chemistry of the brain.

As we stop and think about what made the brain enlarge we hear those who say that bipedal movement freed up our hands. Now you can walk and juggle or do other tricks.  Another theory posits that early hominids could now carry food back to their tribe, make tools, ultimately jewelry and developed other useful talents. Whatever occurred likely was multi-factorial and not a simple single means event.

In keeping with Darwinian principles, it is incorrect to say that the environment created changes. We need to look to see what environmental features were taken advantage of by those best prepared to do so. Mutations are random, selection is purposeful, and geared towards the survival of those most fit for the environment. There are a variety of phenotypes present at any time, and those exhibiting desirable and helpful characteristics do survive and pass on those useful genes.

Mammalian brains produce BDNF (brain derived neurotrophic factor) which assists in neural plasticity and in the creation of new neural cross links. Humans today moving at high rates of oxygen uptake show that at up to 60% of maximum VO2, several things come into play. The first is an increase in Cerebral Blood Flow (CBF). The CBF increases as does the production of  BDNF and other compounds that among other effects stimulate brain growth and development. These other compounds include IGF-1 (insulin growth factor 1), VEGF (vascular endothelial growth factor), and FGF (fibroblast growth factor).

Bathing the brain in this enhanced biochemical “miracle grow” mix, likely would have resulted in superior neural growth and response for those who were best able to respond to this physical and neurological environment.  This seems to have been a contributing factor in the maximal development of the early hominid brain, and continued down through the hominid line.

Those most able to respond to the biochemical results of their activity of  motion, movement, and gathering would have become the smartest of the lot and been most likely to survive . They would be better suited for survival and more able to pass on their genes.  Bipedal movement in hominids was first to be short in duration. Lasting for only a limited distance and allowed for limited scavenging.  Ultimately it resulted in habitual and obligate bipedalism of longer duration, and finally in walking and then, later, running.

There have been debates over the energetics of bipedal motion versus brachiation and advantages over older forms of quadripedal locomotion. But with the thought that nothing gets wasted, if the energetics don’t balance perfectly it is probable that the energy itself that may not have been optimally efficient for walking, certainly was put to excellent use in the development, enhancement, and gradual evolution of the hominid and ultimately modern human brain.

Bipedal walking allowed the former tree apes a  better and more easily sustained motion. This  over the course of time, possibly led to persistence hunting, or at the least an expanded range for gathering, foraging, and then much later hunting. And the migration out of Africa was another sustained effort and may have stimulated brain development.

Sensory stimuli, socialization, diet, and many factors went into brain evolution and development. Then, as now, it is likely that the sustained efforts of moving increased focus, attention, and concentration. Creating mental maps of where they had been, and how to return home gave their small brains a work out. And speculating a bit, ultimately mental maps led to many other things and perhaps even primitive games of hide and seek.  Later came blind folded chess and google maps.

Many facets of evolutionary thought are interesting and valuable. Socialization and network theory, the role of sensory stimulation all are explorable, viable theories and played a major role in evolution. Here we’ve brought into play another facet of hominid evolution not previously described. The energetics and resultant neurochemical (and other changes) as a result of  motion, movement and exercise is a contributing and driving force for brain development and evolution. Put this in the context of the fact that everything moves and there is nothing entirely still in the universe, we have another small factor to consider about our world and how we and it have evolved.

So it seems we weren’t just born to walk or run. We were born to think, develop and evolve. In fact, we’ve evolved to evolve. And evolution continues today. If your thoughts stop with barefoot running, and you think our evolution stopped then, you’ve got a lot more thinking and catching up to do. Exercise and movement are good for what ails you, and assisted in the development of today’s modern human brain.

(Outline presented at American Podiatric Medical Association Annual Scientific Seminar. August 1, 2009. Toronto, Canada)

I had the opportunity to speak at the American Podiatric Medical Association’s Annual Scientific Seminar this weekend. The American College of Podiatric Sports Medicine also held it’s annual meeting here in Toronto. The meetings were excellent. And, as always, it gave me the opportunity to see many people who I cannot often visit with. Old friends, new friends, very old friends, and students from many years ago were all a pleasure to see. There were several people who because of time constraints all we could manage was a hello. The lecturers were excellent. And the ones I enjoyed the most were given by friends I’ve heard lecture many times. But, of course, I did enjoy some other lecturers who I had not heard speak before. Unfortunately, there is never enough time to really visit the city in which the conference takes place. But the people I met in Toronto were all great and friendly.

My lecture was titled “Exercise: Good For What Ails You”, but that was the take off point. I promised there would be resources online that I’d link to and the start of that is available. I plan to place large parts of the lecture including the text (minus some images) of the slides, along with a recording of it (minus some of the humor) online. Hopefully in an expanded version.

In the meantime, I’ve placed selected references and links to articles that cover some portions of the lecture. Many of those articles were here on the blog. More are in the making.

Supplemental materials for “Exercise: Good For What Ails You”

The Bare Outline of Bipedal Beginnings

Humans are the only primate habitual, obligate, bipedal on the planet. And not only can we walk, but we can launch ourselves completely off the ground and run. It is important to note that running is a one legged exercise. Only one limb is in contact with the ground at any time. This has implications for both energetics, efficiency, and the type of injuries that we end up with in the present.

How did we get here? The middle part of the story is that there seems to be a relationship between tree apes and those of us who ended up on the ground. Our structure is homologous, yet different in many respects. In becoming the first runners the fossil and bone evidence seems to be that we first stood upright before our skull and brain enlarged. Australopithecus has a small skull, yet seems built for bipedal movement.  Some feel that Australopithecus could not run, and that it’s bipedal locomotion was a shuffling gait. Remnants of the apes remained, particularly the long upper limbs and curved fingers. Changes occurred in the feet. The great (first) toe and first metatarsal moved closer to the rest of the toes and was no longer opposable like the thumb. The limbs functioned better nearly straight. The pelvis changed and the spine changed to allow for limb connections. The knees could extend fully and lock.  The spine changed both with curves to better position the center of gravity and to allow for the new way in which the skull was oriented to allow for an upright head with eyes looking forward.

Following the development of upright posture, we had two free hands that could be used to carry tools, hunting implements, or food. We could move about fairly efficiently on the ground. We could range far in order to find food. Chimps and apes do not have a wide hunting range to gather food. As we ranged about, we found non-plant sources of protein. This enhanced the development of those built to use the protein, and allowed for eventually the development of a larger brain. This in turn led to the development of the genus homo, including Homo Erectus and later Homo Habilis.

The control of fire, and the use of fire for cooking made for easy to digest protein sources and richer, more calorie dense food. Some feel that the socialization that may have arisen around the ritual of cooking and meals helped enriched humans both culturally and socially. No food fights or no food!

As we developed more and more complex, those with larger brains, and skulls to hold them needed to be born through a larger pelvis. Eventually the pelvis enlarged in two different ways, Neandertal in width and our branch of hominids in an anterior – posterior direction.

Shortly we’ll take a look at the first runners. These first runners had larger gluteal muscles, a longer Achilles tendon, and even developed a bit of an arch along with toes that were all in line. Our knees could lock out. We already could look straight ahead and move on two limbs. As we became obligate bipeds we could no longer climb trees as well as those that came earlier.  I expect to have more details with recommended readings and references on my main web site. And of course, follow up here. To quote Charles Darwin in The Origin of Species: “To treat this subject at all properly, a long catalogue of dry facts should be given; but these I shall reserve for my future work.”

Science Magazine 323 Feb 27, 2009

Science magazine has just published an article on the oldest footprints found which correspond to modern day human biomechanical function. These footprints are about 1.5 Million years old and appear to belong to homo erectus, a species which predated homo sapiens.

The great toe was in similar alignment to modern day humans. An arch was present. Heel strike occurred at initial contact, weight transfer progressed forward with apparent foot function in the midfoot (midtarsal joint) proceeding in a modern manner. Weight bearing then went to the central metatarsals, (seemingly bearing more than the first metatarsal) followed by push off at the big toe.

The foot prints appear to show someone slowed to a near stop (or starting from a stop) and then picking up speed. To my eye, with an initial angle of gait being first high on the left, than on the right (about 24-26 degrees), followed by a narrow angle of gait (about 1 degree) as speed picked up, it looked as though the pre-human hominid was looking to the left, and then to the right. He likely would have been able to cross some of our streets, at least those with traffic bearing to the right side of the road. And in fact he may have avoided getting run over by a bovine, which blotted out part of one of his foot prints.

Bipedalism, walking on two limbs, was an important evolutionary step. Bipedalism is thought to have been present for about 6 million years.  It is energy efficient. It allows free hands to carry things, make tools, build things that are more complex than bird’s nests and beaver’s dams. It frees the hands  for hunting and fishing. Ultimately, it led to holding hands while walking. It led to artistic undertaking such as cave paintings, fashioning musical instruments, fingering the holes of a flute or playing chords and notes on strings. But, it also led some to throw stones at others. But that is another story.

The energy saved may have led to enhanced brain function. The energetics of bipedal walking, determined on an individual basis (some calculations have been done on chimpanzees) show a significant reduction in energy cost for walking in a bipedal manner. Some theorists believe that upright walking, and even running came before the larger skull and brain size.  That may very well have been true, based on these and other findings. There are many interesting adaptations and changes that occurred over the years. Some of the differences that occurred evolutionarily that are important to human bipedalism and are of significant, walking and running energetics include altered f0rm and function of the calf muscle, Achilles tendon, and the gluteal muscles. But, we can’t judge all of that from the footprints alone.

Science 323, 1197 (2009);  Early Hominin Foot Morphology Based on 1.5-Million-Year-Old Footprints from Ileret, Kenya. Matthew R. Bennett, et. al.

Science Now “Early Humans Toed The Line”

Music + Video: “Walk This Way”

Music + Video: “Walk The Line”