A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.

Robert A. Heinlein

Introduction

This article is ultimately about feet. In this respect, I continue the focus of my other articles for this journal (Boblett 2014, 2015). However, you will rarely encounter direct references to feet in what follows. In this more general survey, I try to put the three- dimensional foot into the context of a three- dimensional body. The human foot only moves in three dimensions when it expresses a body moving in all three dimensions. The foot expresses – or suppresses – what we express or suppress in the rest of the body.

However, instead of going bone-by-bone and muscle-by-muscle into various possible distortions of the body superior to the malleoli, I will take a phylogenetic approach. For readers accustomed to my usual anatomy-geek writing, what follows may appear diffuse and sometimes simplistic, but the material seems to require it. I propose to go through a brief survey of the development of bipedalism, emphasizing old assumptions that are contradicted by newer research in physical anthropology. Much of this will repeat what you learned in school, but what you learned in school may have been updated – in surprising ways.

How does this help my work – and perhaps yours? Simply put, when a human body loses ranges of motion, I must look for the demands no longer placed on it. To identify these lost movements, I must ask what this human body was originally designed to do. However, that word ‘originally’ is tricky. Like the human brain with its various layers, our body is a collection of ad hoc add-ons, put there somewhat  randomly in response to changing requirements. Nature is parsimonious. If it ain’t broke, nature won’t  fix it. We  know that animals evolve. We pay less attention to the fact that animals don’t change old structures unless they must. They just stick stuff on.

So my focus here is on biomechanics, old and new. My emphasis is on shifting ecological strategies: how a long lineage of ancestral species adapted to new environments and opportunities. My theme is avoidance of overspecialization, since physical generalism continues to be one of the strongest advantages of our present species.

In the case of the human body, we’re looking at a Swiss Army knife. It has multiple applications reflecting multiple demands. We are generalists, not specialists. This is because many of the assumptions made  in physical anthropology a generation ago turn out to be wrong, both with respect to the ecological demands placed on our ancestors and with respect to our changing responses to these demands. This in turn has implications for our present biomechanical options.

I repeat: much of this material will seem old-hat to you. Just be prepared for a few surprises.

The Path to Uprightness – Tiny Quadrupeds

Once upon a time, our path was a branch. Please don’t roll your eyes. Yes, I’m going back to the Mesozoic Era, but I won’t stay there for long, I promise.

As primates and indeed as mammals, we begin with a design that differed little from that of most terrestrial quadrupeds: relatively short limbs supported a horizontal spine, usually. The difference was size. Moving out of horizontality by climbing or leaping could occur  only  if the overall body remained very small. In the three-dimensional world of the jungle canopy, the ancestors of tigers, whales, mammoths, and monkeys all had a rat-like form, severely restricted by the weight- bearing abilities of tree branches. We could scurry along branches on four legs, moving like any other quadruped along our little tree-trails. Like our close cousins, the rodents, we had long tails to supply some extra balance. We also had good jumping abilities; but weighing more than a few ounces was impossible.

Then came the revolution. In his wonderful book The Ancestor’s Tale, Richard Dawkins (2004) points out that the biomechanics of ‘higher’ primates like lemurs and eventually monkeys represent a solution to the problem of size. After the mass extinctions that ushered in the Cenozoic Era, most mammals rushed down into newly vacant ecological niches. Primates stayed behind to maximize their greater monopoly over the tree canopy. They did this with a simple expedient: rotation, rotation, rotation. Forelimbs and hind limbs elongated. Scapulae and ilia differentiated. Heads lifted. Eyes rotated forward. Depth perception improved. Hands and feet could grasp, pull, and manipulate. Limbs and spines could rotate in nearly limitless combinations of ways. The common denominator in all this was independent rotation of cylinders throughout the body. The result: monkeys could be much bigger than tree-shrews, rarely leaving the three- dimensional world of the tree canopy.

Simply put, our ‘higher’ primate ancestors rounded out the shape of what Hubert Godard calls the kinesphere, the area into which we can reach and from which we can pull. Our kinesphere became more . . . spherical.

But wait a minute! What has this to do with bipedalism? We no longer live in the trees, do we? What did we lose when we left the trees? What compromises did we have to make?

Short answer: we are more like monkeys than we may suppose. Most of our monkey- like rotational ability is still available to us. And it is central to our present multiplicity of possible movement.

Long answer: there is the revolution in physical anthropology that is changing what many of us learned in high school. The transition to bipedalism was longer and more complicated than we once thought. Ecologically and biomechanically, we lost less than we once supposed. This includes the articulation – and articulateness – of our feet.

The Path to Uprightness – Climbing and Shuffling

The old story is pretty straightforward. Until about seven million years ago, we lived in trees. Eastern and southern Africa were covered with thick forest. Then things

dried up. Things cooled down. Trees died. Grasslands spread. Our ancestors came down from the trees and never looked back. We became bipeds. Arms shortened. Legs lengthened. Flexible arches became rigid. Opposable big toes became merely abducted, then lined up with the other toes. Calcanei no longer supported extreme dorsiflexion of the ankle. Hands and feet specialized for very different tasks.

New version: the old jungle canopy fragmented. A mosaic of little ecosystemsmr gd . M o v ig bt wen t hsecosystems, our ancestors  specialized in not specializing. They applied their arboreal three-dimensionality to the new opportunities of their world. We became the ‘obstacle-course animal’, designed to run, jump, swim, climb, crawl, throw things, dodge things, and otherwise do whatever it took to survive in many adjacent little ecological niches.

The result is an animal more like a jackal than a lion. Physically, we are opportunistic omnivores, not top predators (and top predators are particularly prone to extinction). We are designed to be agile, flexible, adaptable, multitalented, and multidirectional, what Homer calls polytropos or ‘many-turning’. We do many things very well rather than one thing exceedingly well. Dolphins can’t climb trees. Lions don’t have thumbs.

Okay, but how did this happen? I begin with the fact that bipedalism evolved in at least two stages, the first of which I address in this section.

First-stage bipedalism seemed designed to justify the worst fears of those who wonder what we lost when we left the trees. Whether the early biped Ardipithecus ramidus some seven million years ago or the entire genus Australopithecus up to the emergence  of the genus Homo roughly 2.5 million years ago, we see an ape-like shortening of legs, necks, and torsos relative to monkeys and the ‘lower’ apes like gibbons. It’s not just that the legs were short and stumpy; the whole body was short and stumpy. The face was round, dominated by strong jaws and thick neck muscles. Shoulders rose till they approached ears. The torso was long in relation to the legs, but it was round and relatively immobile. Waistlines expanded, with conical ribcages and pelvises joining their wide ends to enclose massive guts. On two legs, these animals probably did not so much run as shuffle, with a minimum of contralateral movement.

There’s no point saying that these animals were ‘transitional species’. In nature, nobody turns to a predator and says, “Slow down, man! I’m  a  transitional  species!” In fact, these various creatures were still tree-climbers, improving their ability to avoid capture. The explanation is partly ecological. Ardipithecus still lived in a forested environment. The best explanation for its occasional bipedalism is an improved ability to carry foodstuffs. In other words, the new adaptation probably had more to do with sexual favors than locomotion. Hence, the smaller canine teeth found  in Ardipithecus males, who apparently preferred bribery to battle. In addition, Ardipithecus had a fully opposable big toe, indicating great comfort in the trees.

In contrast, the different species of the genus Australopithecus more strongly suggest adaptations to fragmentation of the tree canopy. However, they were still not entirely the savannah chimps of popular science. Starting some 3.75 million years ago, their diet certainly expanded to include grassland nutrition, but  they  continued to draw on woodlands for some of their diet. This mixture shows clearly in fossil bones in the mixture of carbon isotope data reflecting consumption of plants following C3 and C4 photosynthetic pathways. C3 plants include trees, shrubs, and cool season grasses, while C4 plants include warm season grasses and succulents. It would  be interesting to study different ratios in different australopithicene species, but I have not found this data.

More tellingly, there has been a paradigm shift regarding the biomechanics of Australopithecus. Anthropologists compared australopithicene calcanei to that of apes and humans respectively. Since the Australopithecus calcanei more closely resembled those of Homo, they reasoned, they could not allow enough dorsiflexion for good climbing. Then videos of African and Indonesian tree-climbers demonstrated that the modern human Achilles tendon is capable of far greater lengthening than most anatomists previously thought possible. In Africa, Indonesia, and other parts of the world, humans climb trees by embracing the trunk and using strong toes and flexible Achilles tendons to literally walk up a tree.

Still, the limitations of australopithicene design are obvious. I go back to my description of both Ardipithecus and Australopithecus: short, stubby, high- shouldered,  big-bellied  creatures who probably shuffled when they walked upright. Compared to monkeys or gibbons, even the most gracile Australopithecus does not look very agile. Bipedalism doesn’t look like a good bet. Then something new shows up.

The Path to Uprightness –

Homo

With the genus Homo, it’s as if the skeleton of Australopithecus was grabbed at both ends and pulled like taffy. Everything elongates. The cranium has a higher dome. Jaws are narrower. The neck elongates. Down below, legs begin to lengthen relative to arms, but the real shift is in the middle – a waist develops! The rib cage is narrower, as is the pelvis, but they also separate. A longer space develops between the bottom of the rib cage and the top of the pelvis. More important, this space moves: it rotates, it sidebends, it bends forward and backward. This leads to a dramatic increase in the dynamism of the overall pattern. All without a single extra vertebra.

In other words, much of the rotational ability of monkeys and gibbons came back. Contralateral movement is more efficient. Bipedalism changes radically. This animal is a runner! Notice that I use the present tense now. I am describing . . . you.

Even more striking, this change happens very quickly. With the exception of the skull, the skeleton of the genus Homo has changed very little through various species over roughly 2.5 million years. In Africa, bone-hunters who find anything Homo pray fiercely for a skull, since otherwise the species could be anything. It’s as if Mother Nature said, “Don’t change the body. Just unscrew the head and put a new one on. Repeat the process after a few thousand generations.” The brain of a Homo habilis ranges from 500 to 700 cc, compared to 1,200 to 1,500 cc for Homo sapiens. Otherwise, apart from a smallish size and arm-to-leg ratios well within the range of Homo sapiens variation (I’m close on both counts), this creature is . . . you.

The result is a super-generalist, a jack-of- all-trades. This is an animal who can invade and thrive in different ecosystems. From this you get the animal that leaves Africa altogether, infiltrating widely different ecosystems across the planet, hot and cold, wet and dry. As Ian Tattersall (1993) points out in his book The Human Odyssey, our success is not a product of superior intelligence alone. The human body had this ability long before anything like the Homo sapiens brain evolved.

So, until recently, the emergence of Homo seemed sudden and seamless. But with the discovery of a possible new species in Homo naledi, we may be seeing the change in the midst of happening. Of course, I am aware that these south African fossils and their interpretations are new and controversial. Is Homo naledi really a separate species from, say, Homo habilis? Is it an ancestor to Homo sapiens? Or is it a dead end, a kind of spinster great-aunt? When did it live? Before H. habilis? Or was naledi, like Homo floriensis, a survival into recent times of a radically different lineage within Homo, our eccentric great-aunt or uncle rather than our ancestor?

Whatever H. naledi was, even if we reject the name naledi itself as denoting a separate species within Homo, the consensus seems to be that here is an example of intense experimentation with physical form and movement. Again, the surviving result of this experimentation is . . . you. This is enough for me. After all, we are experiments as well, are we not?

Homo naledi is of particular interest to me because it involves a surprisingly modern foot attached to archaic features. Specifically, the H.  naledi skeletons  show a modern hand with a robust thumb and power grip, but long, ape-like fingers still curved to enable tree-climbing. The foot, as far as I have read, shows no variations whatever from the modern foot. The surprise comes between these modern hands and feet: the closer we get to the pelvis, the more archaic the body becomes.

So our feet have changed less than the rest of our bodies, even our hands? William Harcourt-Smith of the American Museum of Natural History’s Paleontology Department puts it this way: “Quite obviously, having a very human-like foot was very advantageous to this creature because it was the foot that lost its primitive, or ape-like, features first” (American Museum of Natural History 2015). The idea intrigues me. I take this as further proof that the modern foot can support and express many different kinds of movement, not just what we are accustomed to doing in the modern world.

How Do We Apply All This?

Did you enjoy this little journey? Maybe yes, maybe no. So what has this to do with bunions, migraines, tight hips, sore backs, or constricted lungs? More profoundly, what has this to do with the emotional, cognitive, and spiritual disconnects of a wild animal trying to be a domesticated one? How do we open this cage? How do we rehabilitate this animal and release it?

Anybody who knows me will say,  “OK,    I get it. Homo sapiens never entirely came down from the trees.” And I grant you, that’s a large part of my agenda. Children, acrobats, hunter-gatherers, and many yogis understand implicitly that gravity can pull us from above as well as from below. Sailors who work with rigging understand this as well. So we can mediate gravity through our shoulder girdles as well as through our hips . . . and we sometimes must. For both girdles to work freely, scapulae must sometimes mediate weight, allowing ilia and core muscles to help in other ways.  In turn, this will expand and enrich our lower-girdle movements in bipedalism. Try swinging from monkey bars and then walking. Different gait, yes? This is what I mean by three-dimensionally.

Adding this movement option back into the lives of ‘ordinary’ people can produce profound changes. So yes, I like parkour, hanging yoga, monkey bars, jungle gyms, climbing ropes, Swedish ladders – and actual trees. I’m a bit less fond of wall- climbing because it resembles tree-climbing rather less than the things I just listed.

But there’s a bit more specificity to this. As I always do, I will avoid attempting a comprehensive list in favor of dropping a few hints. Here they are.

If Homo sapiens is still partly arboreal, how might that apply to freeing the shoulder girdle, the elbows, the wrists, the spine, or the hips? The trick is getting the client to the point of being able to hang in the first place without irritating the subacromial bursa or the bicipital groove, if either of these is the problem area.

To most of my clients I recommend a pull- up bar hung in a doorframe. Instead of chin-ups, I simply suggest strengthening the hand muscles by pulling up the knees and hanging with arms at full length. A clock or stopwatch within easy view can help the client time the period of hanging. Gradually, it may be possible to lengthen the hanging time to several minutes. Based on this, the client may then be able to do some amazing stretches with arms and shoulders directed upward. Even  the momentary experience of taking the spine out of gravity can work wonders.

A pull-up bar has several advantages over an inversion table (though I use one of   the latter periodically): the bar is cheaper, it takes up less space, it can be installed  or removed quickly, you can get into or out of position quickly – and nobody’s hands get stuck on a pull-up bar. By the way, Rolfers and other bodyworkers can increase hand-strength by hanging, a lesson I learned from Victor Geberin years ago. I have narrow little thumbs, but they are far from wearing out.

I have suggested that hanging can help free not only a messed-up shoulder, but also other joints. What about swinging? While humans do not precisely brachiate, I notice that work on monkey bars followed by gait work can open up amazing dimensions  in the latter. Scapulae send interesting messages to ilia once the scapulae experience the sensation of mediating gravity from above.

More general questions involve the movement strategies of ‘Internals’ versus ‘Externals’ (from Jan Sultan’s Internal- External typology). Sultan has pointed out that neither type has priority in our evolution, physical or cultural. Hunter- gatherers, for example, do not tend to cluster in one group or the other. Photos of Native American gatherings clearly show both types within the same tribe (I sometimes wonder about the extremely lordotic !Kung of the Kalahari Desert, but that’s another story entirely).

For convenience, I think of the Internal type as more monkey-like and the External type as more ape-like. I like to think that these movement strategies reflect a deep ambiguity in our evolution between the flexibility of a monkey and the stability required in the larger body of an ape, since we apparently never walked on our knuckles. Certainly the acrobatic potential of the Internal body can be great, and Internals are somewhat more likely to have a high arm-to-leg ratio, though exceptions exist. What innate gifts do Externals bring to the three-dimensional world? I sense that just flexibility versus stability is not the full story here.

For either type, the prehensile foot is a useful tool; but toe function is not confined to picking things up or grasping things between the big toe and its neighbors. What role does the arch play when the Achilles lengthens enough for a human being to ‘walk’ up a tree or its equivalent? How might reclaiming that ability, if only in part, change horizontal gait?

These are a few hints. I’m sure you have more. This brings me to my conclusion.

The Ball’s in Your Court

Many of you have studied anthropology. Some of you have studied primatology. A few of you have peered even further back into our ancient phylogeny. I do not pretend to have mastered the previous work of writers like Sultan, whose work I mention here, or Kevin Frank, whose work I do not. (I owe much to Frank’s movement work for making me conscious of very primal movement patterns.)

So once again my partial view is an invitation to conversation. What have I written that’s already a cliché? What am I missing? Where am I flat-out wrong? Where am I just one-sided? Are there alternative explanations for what I describe? Are there additional strategies that could come from these explanations? In sum, can our views reflect even more of the multiplicity of our biomechanics? Clearly, one paradigm is not enough.

Bibliography

American Museum of Natural History 2015. “Foot fossils of human relative illustrate evolutionary ‘messiness’ of bipedal walking: Study of Homo naledi suggests that new species walked upright and also climbed trees.” ScienceDaily. 10 / 6 / 2015 . www. sciencedaily. com/ releases/ 2015 / 10 / 151006131938 . htm (retrieved 10/22/2015).

Boblett, M. 2015 Nov. “ The Three- Dimensional Foot Part 2: Evoking Pattern- Consistent Competency.” Structural Integration: The Journal of the Rolf Institute® 43(3):55-57.

Boblett, M. 2014 Dec. “ The Three- Dimensional Foot: The Role of the Toes and Metatarsals in a Typology of Transverse- Arch Rotations.” Structural Integration: The Journal of the Rolf Institute® 42(2):33-38.

Dawkins, R. 2004. The Ancestor’s Tale: A Pilgrimage to the Dawn of Evolution. New York: Houghton Mifflin.

Tattersall, I. 1993. The Human Odyssey: Four Million Years of Human Evolution. New York: Prentice Hall.

Michael Boblett works in San Diego, California. He has been a Certified Rolfer since 2003 and a Certified Advanced Rolfer since 2008. Michael is a retired Unitarian minister. His advanced degrees (MA, MDiv, and  DMin) are from Pacific School of Religion in Berkeley,

California. At seminary, he focused on the anthropology of religion, with experiential training under Michael Harner, author of The Way of the Shaman. Michael runs marathons and hikes up mountains wearing Vibram Five Fingers. His website is www.rolfer.biz.