The tent pole and the tensegrity mast
Ida's first analogy for the function of bone was the tent pole. In her public lectures at Topanga and elsewhere through the early 1970s she described the body as a structure held up not by rigid columns but by the balance of soft tissues on either side of those columns, like the canvas of an old camping tent stretched against a central pole. The pole itself was nearly irrelevant to the stability of the whole; it was the tensioning of the canvas — the ropes pulling down on the right balancing the ropes pulling down on the left — that determined whether the tent stood or collapsed when the wind struck. This image gave Ida a way to introduce a counterintuitive idea to a lay audience without yet requiring them to think in the more demanding vocabulary of tensegrity. The bones, she told her listeners, were less like pillars and more like the rigid spacers that kept the soft envelope from collapsing in on itself.
"Now the function of the bones, this is another idea that you have to look at and realize that you are shifting around considerably from what you were taught in high school or in college. In college, were taught or in really more elementary than that. In elementary school, in grade school, and in high school, you were taught that bones held the body up. This is not so except in a very special sense. Bones hold soft tissue apart. Those of you who camped in the days when a tent was instructed that looked like that, remember what it was like to put that tent pole in under the plastic canvas. You had to get your tent pole precisely formed in order that you could take your canvas and you could tie it down with tie ropes so that the left side counterbalanced the right side. And either they balanced and balanced well, or when the when the winds really struck that night, the tent was down on top of you. The right side balanced the left side. The left side pulled down in order to pull the right side up. And the same thing was true of the front and the back. A body is rather like that. There are other things to realize about a body."
Ida at Topanga, walking a lay audience through the inversion that bones hold soft tissue apart, not the body up:
By the mid-1970s the tent-pole image had a more rigorous cousin sitting on the table at the Boulder advanced classes. Buckminster Fuller's tensegrity icosahedra — small wire-and-strut models in which rigid sticks float inside a network of strings without touching each other — had entered the conversation through Peter Melchior, who was working out the implications for human anatomy. In the icosahedron the rigid struts genuinely do not bear weight in the conventional sense; they are held in suspension by the balanced tensioning of the strings around them. Press on the structure and it deforms; let go and it springs back. Peter spent the Boulder sessions trying to translate what he was seeing in these models back into the human skeleton, and what kept emerging was Ida's old claim — that in a living body the bones are not stacked weight-bearing pillars but spacers held in position by the tensional web around them.
"You can put several 100 pounds on it easily and sit it on the That is full of story. Right. And the thing is that you then it's enormously more efficient way of Does that hold so long? Supporting weight. This won't. But a structure made of steel struts and wires will because the limit of the strength of the thing is the limit of the tensile strength of these things and the crush strength or the compressive strength of these members here which you can produce. I mean, if you use titanium wire for example, can make it extremely strong but it doesn't weigh anything. Normally if you wanted to support a couple 100 pounds, you'd have to take something which weighed a substantial quantity of something in order to support but this doesn't and you can still nonetheless support large quantities of weight. Now another consideration for the analogy between these sorts of things in the human body that struck me was that it's a more efficient structure. It's a more efficient way of supporting weight than simply adding one piece on top of the next like this all the way up which is what you expect or what you're led to expect by anatomy books and by looking at skeletons and things of that kind."
Peter Melchior, in the 1975 Boulder advanced class, describing the moment the tensegrity icosahedron rearranged his understanding of the skeleton:
The vertebrae that turn out not to be pillars
Once the tensegrity hypothesis was on the table, the practitioners in Boulder began to test it against the actual anatomy. The vertebral column was the obvious test case. If bones really were spacers rather than weight-bearers, then the vertebrae — which everyone has always treated as stacked compression blocks — should not show the internal architecture of compression-bearing structures. Bob Hines went to the anatomy library and looked, and what he found supported the heresy. The bodies of the vertebrae — the round drum-shaped portions everyone pictures when they imagine spine — have thin cortical bone and no obvious stress lines in the trabecular pattern. The neural arches and spinous processes behind them, which no one had ever called weight-bearing, have thicker cortex and clearer architecture. Whatever the spine is doing in a living body, it is not doing it the way an anatomy textbook says.
"I was doing some thinking about it and looking at anatomy books the other day. And it seemed to me that when you talked about the spine as a mass and that the vertebral bodies are not actually weight carrying blocks, it seemed to me that if that was true, you could could look at a vertebra and see whether or it had, you know, stress lines in the trabeculae just like the head of the femur does and all the bones of the leg do for that matter. So I looked in the anatomy books and it turns out that not only does the vertebral bodies not have stress lines in them, but the compact bone layer, the cortical bone layer on the vertical body is very thin compared to in the spinous process, the transverse process, the whole neural arch So it would seem just from looking at it that the bodies are not weight bearing structures that the main compression structures there are actually the neural arch. And the compressions are gonna be in different. They're not gonna be in horizontal lines."
Bob Hines, having gone to the anatomy books to check the tensegrity claim against actual vertebral architecture:
Peter Melchior took the inquiry further by looking at the geometry of the individual vertebra. What he noticed was that each vertebra has, behind its drum-shaped body, a triangular configuration of processes — and triangles are the one geometrical figure that cannot be deformed without breaking. The dome and the geodesic sphere are built from triangles for exactly this reason. If the spine is constructed of triangular non-deformable elements held in suspension by the tensional structures around them, then the apparent weight-bearing role of the vertebral body becomes much less essential to the whole. The structural job is being done somewhere else.
"There's another triangle, another process coming out in this direction. And also Practically what you've got to hang on there. Oh, here we go. Yeah. See, there is that triangular shape to it. Now that triangle one of the characteristics of triangles as a as a body, if you make it in the world, is it is non deformable. If you take if you take four pieces of you make a square out of by another piece like this, one across the bottom. Then if you just push it, the thing will all collapse in this direction or will collapse in this direction. But if you make a triangle like this, there's no way of deforming that without breaking it. That's true. It's true only of this geometrical figure of a triangle that is non deformable. Every other structure is deformable unless you make it out of triangles and that's the principle, one of the basic principles the dome because it is constructed out of triangle. So is this thing constructed out of triangles? So anyway, that's one clue and that's one of directions in which I've been trying to take this whole investigation, namely can I construct out of these triangular shaped vertebra something which will resemble a tensegrity mass, something which will stand up by itself? So the question then is what is the function of these is the body of the vertebra?"
Peter, having moved from the icosahedron model to the geometry of the individual vertebra:
There was still a problem to be honest about. The vertebral bodies do get compressed in pathological aging — that is what wedging and disc collapse are. The lumbar vertebrae are obviously larger than the cervical, in what looks like a load-bearing gradient. Ida and her circle did not pretend these observations away. What they said instead was that the compression problems of the human spine are not the spine working correctly; they are the spine failing to do what it could do if the tensional web around it were doing its job. The bone, when called upon to bear vertical load alone, eventually loses.
"You see all one of the misleading things about those sections of femur and so on is that they are all average bodies. Right. And using their bones, they carry the weight around. But so are so are these vertebrae. Yeah. And even in even in average bodies, the vertebrae don't look like compression structures at all. Inadequate compression structure. When they do get when they do start to get compressed, they start to get wedged."
The class wrestling with the honest complication — that average bodies, with their failed tensional structures, do force the vertebrae to act as compression units:
The day life dawned: spacers as passive members
The most important moment in the practitioner conversation about bones comes in a 1975 Boulder session in which Peter Melchior describes the day he understood how Fuller's models actually work. He had been sitting with the icosahedron in front of him, listening to Ida's lectures on tape, replaying her sentences until they cohered. One of her sentences was: the bones act as spacers. He turned that phrase over in his hands, applied it to the model, and watched the model rearrange his understanding of the body. What he saw was that when he pulled on a string anywhere on the tensegrity structure, the rigid struts moved — but the struts were not the active members. They were following the tensional changes around them. The bones, in a living body, were doing the same thing.
"One of the things that she stated was that the bones act as spacers. Well now, see here's a thing that has spacers in it. I mean, don't want to call them bones necessarily. That's what the function of these struts are, is spacers. They hold now if you want to call this an analogy to soft tissue, they hold these parts of the thing apart and give it its characteristic shape and structure."
Peter Melchior, recounting the moment Ida's phrase 'the bones act as spacers' became visible to him in Fuller's model:
What followed in Peter's account was the actual mechanism of how a tensegrity body moves. He started pulling on individual strings on the model and watching what happened. From a narrow viewpoint he was moving one strut. But step back, he realized, and what he was actually doing was changing the entire tensional balance of the structure — and the rigid pieces were following those changes, not driving them. This is the conceptual core of what the article is about. Movement in a tensegrity body is not bones moved by muscles attaching to bones; it is the whole tensional web reorganizing itself, with the bones traveling along passively as spacers maintaining the structure's characteristic shape.
"But now as I was mumbling to myself about this, how these things work, it struck me that as I mess with these tensional lines here trying to get things balanced, what I'm doing is I see, if I just look at the thing from a narrow point of view and I start pulling on this particular string here, what I can say to myself is, well, what I'm doing is I'm moving this strut. But if I take a little slightly, if I take a step back from it and look at it and say, you know, what I'm really doing is I'm changing the tensional structure all around the outside of the thing and these creatures, these spacers, these hard pieces are following those changes in the tension."
Peter, continuing — the day the life dawned, when he saw that pulling a tensional line moves the strut, but the strut is following, not leading:
The conclusion Peter drew was as direct as it could be made. The bones, in his account, are passive. They are spacers maintaining the form of the tensional structure. They are not the active agents of movement. What moves a body is the reorganization of tension across the fascial web, and the bones come along for the ride.
"These things are, as it were, passive. They are not the active members."
The summary line — short, direct, and unmistakable:
Compression and tension distributed through the whole
The discussion did not stay at the level of Peter's icosahedron. As the senior practitioners worked the model through their fingers and minds, they began to ask what happens to bone itself when the surrounding tensional structure improves. The classical model assigns bone the role of carrying compression and muscle the role of producing motion. The tensegrity model dissolves that division of labor. In a body whose web is properly tensioned, bones may carry some tension; in a body whose web is collapsing, bones may carry far more compression than is good for them. Joe, one of the practitioners in Boulder in 1975, articulates the dynamic version of this.
"But suppose this one came out of the back door, this one came out of the front door, and where they intersected here, they did different things. Well, then you wouldn't find one of them because it wouldn't agree down here. So that's Chuck is very anxious to say something. So it's Joe. One thing on the compression and tension, like, in the static model, when people have come in looking like granite standing there rigid hard, I imagine their bones are acting in compression, where in the moving body, bones start taking on tension. In other words, when Norm's knee was spanning or his fibula was spanning, I'll bet you that bone was either nothing in it, no tension, no stresses in it, everything was balanced from top to bottom, or there may have been some tension in it. And I suspect the more you're floating, the more tension goes into the bones and the less compression. Although, I meant it's also an ossulary thing where the bones take on tension and compression. But it's not like the the bone is a space that takes compression. But bone about that bone, though, is, like, when Norm's bone here. What that does is put us looking from here to here."
Joe in the 1975 Boulder class, describing how the same bone can act in compression in a static, rigid body and in tension in a fluid, floating one:
There is one important caveat in the practitioner conversation, which the group does not paper over. Living bone is not a steel strut. It responds to load by remodeling. Jan Sultan, in the same Boulder discussion, points out that the bones of the lower leg are apparently vertical and straight, which seems to argue for at least some genuine compression-bearing function in human bodies that spend most of their lives upright. Peter acknowledges the difficulty. The hypothesis that any given bone in the body represents lines of compression is, he admits, hard to work with — what about a curving rib, what about the lumbar in a leaping animal? The model is not closed.
"See, now again, my hypothesis and it's strictly a working hypothesis has been that any given bone in the body represents compression lines. Now that's a wild hypothesis, mean it's a difficult hypothesis really to work with because then you think well a rib, curve that's coming around, well how can that represent the compression part exactly? That's a toughie. There's also the problem of the limbs and of the leg. Now, see one argument which I've had to try to deal with is that see, in the bones of the lower leg, they are apparently vertical, straight up and down. So therefore, they're not a tensegrity structure because if you put this thing straight up and down and put weight on top of it here, So the rest of it is in a way is rendered superfluous. Now I don't I don't know exactly what to say about that yet. Although, of course, in a moving human being, they are vertical only a very small part of the time."
Peter, naming the working hypothesis and the difficulty with it:
The honest unresolved residue of the discussion was that bones in living human beings probably do both jobs depending on circumstance. They act as compression-bearing columns when the tensional structure has collapsed; they act as floating spacers when the tensional structure is in good order. The work of Structural Integration moves a body from the first state toward the second.
What this means for the practitioner: do not push the bone
The tensegrity model is not merely a theoretical preference. It dictates how the practitioner works. If bones are spacers following the tensional web, then any attempt to address a misaligned bone by pushing on the bone itself is methodologically wrong. You change the tension and the bone moves. You push on the bone and the tension reasserts itself the moment your hand leaves. This is the technical difference Ida insisted on between her work and chiropractic, and the difference she went over repeatedly when students asked about working a displaced coccyx or a rotated vertebra.
"You stretch fashion planes, fashion materials that determine the position of that coccyx. It's the same old story. You do not get ahold of a bone and by force do something with it. I have a question at this point. Do you ever work around the coccyx before you work on the rotators? Yesterday, Don's coccyx got much worse as we worked on the rotators because I think the sacrum came back and the cocci dove more. Oh, ever is a long time. And I realized that when I pontificate about you always do so and so, at the half an hour after, I'm looking at myself and saying, I thought I heard you say you're gonna do this."
Ida, dismissing the idea that the practitioner addresses a bone by getting hold of the bone:
Ida's reasoning here is consistent with everything else in her teaching about fascia. Fascial tissue orients itself along the lines of stress it receives. Pull on a bone and you do not move it through space; you signal the fascia to thicken and tighten along the line of your pull, which deepens rather than corrects the problem. The practitioner's job is to change the stress patterns in the soft tissue so that the fascia reorganizes along new lines, and the bony spacer settles into the new position the new tension prescribes.
"You know, with fascia, and you said by stretching a bone or stretching a coccyx, it does not increase the length. And this is by fascial tissue is very definite. It is that it will grow in the lines of stress and become stronger in the lines of stress. If you pull on the bone, it will orient itself towards the lines of stress and become tighter and stronger in that direction. But I don't know."
A practitioner in the class, articulating the fascial-stress argument for why pushing bones produces the opposite of the intended result:
The bone in the man's collar
Ida had a teaching image she returned to when she wanted students to feel rather than think the spacer doctrine. The image was the bone in the man's collar — the stiffener inside a starched shirt collar that gives the collar its shape. The bone in the collar is genuinely necessary to the form. Take it out and the collar collapses. But it is not the active member of anything. It does not move; it does not pull; it does no work. It is a spacer. And anyone who has worn such a shirt understands intuitively that the collar's shape is given by the cloth as much as by the stiffener. The image lets a student feel what a spacer is before they have to argue about whether vertebrae do or do not bear compression.
"And then I begin to get the sense, well, what I want to when I'm working on someone, what I want to create is like working on a leg, is the the continuity that goes all through the leg will be a function of soft tissue continuity and not a function of the hard tissue continuity, Have which is the way you ever me talk about to very elementary audiences, talk about the bone being like the bone in the man's color? There are still bones around in the man's color. When you've got a model there, you take the bone out of the man's color, and it has a form of its own, which is not given by that bone, but when you get the bone in there, the bone preserves it."
Ida, using the bone-in-the-collar image to make the spacer doctrine tangible:
What the bone-in-the-collar image teaches the practitioner is to stop thinking about bones at all during much of the work. Ida said this explicitly in the same Boulder session: the most useful mental discipline for a Structural Integration practitioner is to imagine, while working, that the bones are not there. The continuity through a leg is given by soft-tissue continuity. The way one part of the body connects to another part is given by the fascial planes that span between them. Once a practitioner stops trying to track bones and starts tracking the tensional web, the work becomes possible in a way it cannot be when the practitioner is still mentally palpating a skeleton.
"That's I find that a really helpful way of thinking about body is I don't think about the bones, but Is there a way to and imagine that the bones weren't there at all. And then I begin to get the sense, well, what I want to when I'm working on someone, what I want to create is like working on a leg, is the the continuity that goes all through the leg will be a function of soft tissue continuity and not a function of the hard tissue continuity, Have which is the way you ever me talk about to very elementary audiences, talk about the bone being like the bone in the man's color? There are still bones around in the man's color."
Ida, naming the practitioner's mental discipline that the spacer doctrine requires:
Muscles tension the web; the web moves the spacers
Once bones are reconceived as spacers, muscle has to be reconceived too. The classical model has muscle as the active mover, pulling on bones across joints to produce motion. The tensegrity model puts muscle in a different role: muscle tensions the fascial web, and the change in the web's tension is what produces both shape and motion. The bone follows. This was a hard reformulation to articulate, and it took the Boulder group several passes to get the words right. Jan Sultan offered one version in 1975 — the muscles are there to move planes of fascia — and Ida pushed back on the word 'only,' but accepted the substance. The cleanest version came when the group landed on the formula: the muscles are for tensioning the web.
"The muscles are for tensioning the web. Right. That's what I wanted to see. And in the course of that, sometimes they may shorten the course of that may work or they may provide support along with their longitudinal access. That's a lot. I wish that someone of you was right up there at the six hundredth time right now. And to find out how to express what you saw going on yesterday."
Jan Sultan and Ida converging on the cleanest statement of what muscles do in a tensegrity body:
There is a striking observation that the senior practitioners made during the same sessions about what happens to a joint when it is properly worked. The classical model predicts that releasing a joint should make it feel looser — and it does. But the practitioners noticed something else. The joint also acquired a new strength. As the long segments of the body broke into smaller, more differentiated movements, each smaller segment showed both more freedom and more integrity. This is what one would predict from a tensegrity structure: as the tensional balance improves, each part is held more precisely in position by the web, and the apparent paradox of looseness and strength resolves.
"As that happens, you get kind of a new strength, well it's what we call integrity but it's kind of a descriptive word for it. It's like even though you are getting looseness, all of a sudden you are getting a togetherness, a strength, a continuity to that joint that gives it a new strength while it has to straighten. It seems to me that the random body holds on to security or strength by keeping long segments because it doesn't have probably that intrinsic motion that we were talking about before. It can't deal with fine movements or discrete movements. But what we see when we see a balanced joint now is that not only does it come loose, we all work and work and work to to the loose. Then as you get to smaller segments and you get balance of the flexors and the extensors, then all of a sudden you start seeing this new strength, this new balance, this new need, brings that lift, I think, that you're talking about, the weight going out. That does."
A senior practitioner at Big Sur 1973, describing the paradoxical strength that emerges when joints are released into smaller-segment movement:
The same passage names something the classical model has no language for: the way a properly worked joint shows a kind of liquidity in its intrinsic motion. This is not muscles pulling on bones. It is the whole tensional structure of the joint reorganizing, with the bones as spacers floating in the new arrangement. The Boulder group spent some effort trying to find a name for this — 'intrinsic motion' felt inadequate because it evoked the very model they were trying to leave behind.
"When I was watching and seeing when Ada was working on Takashi and when Tim was working on Carol, it's that intrinsic movement of the elbow joint, that there's a very special quality to it of liquidity, of liquidness, of soft tissue character. Now, that seems to me inadequately described as intrinsically, but not only because it doesn't really tell us very much, but because it evokes that old model of muscles pull on bones. What we're seeing precisely is not that. That's right. It's as if everything has let go. Everything has let go and so that's exactly the state where the muscles are not pulling on the bones and therefore to call it intrinsic movement is a way highly misleading because you've got contradictory pictures or at least if you're trying to convey to someone a new picture, that won't do it. That's right. On the four colors. What should we call it? Let's find a Well, let's leave it where it is right now And everybody just kind of let that roll around in your head and see if there's any anything else emerging. On a different subject, I was on the tensegrity model. I was doing some thinking about it and looking at anatomy books the other day."
The Boulder class trying to name what the released joint actually shows, and why 'muscles pulling on bones' fails to describe it:
The intrinsics that mediate between extrinsics and bone
In a 1973 Big Sur session, the senior practitioners worked through a related anatomical question: if bones are spacers and muscles tension the web, what is the role of the deep muscles — the intrinsics — that sit closest to the bone? The answer they converged on was that the intrinsics are the mediating layer. The extrinsic muscles, the long surface movers, act on the structural framework by way of the intrinsics; the intrinsics establish the proper relationship of the bony spacers to each other; and only then do the extrinsics produce coordinated motion across joints. A random body, by contrast, recruits the extrinsics directly to bracing tasks because the intrinsics are not doing their job. The result is gross humped movement rather than fine differentiation.
"You see what Robert was implying, and that is that when someone goes to move, and this shows up in Valerie Hunt's data, when someone goes to move, they literally have to get a hold of the whole of a man is in his bones. In other words, there's an immovable fluidity to these bones and on these bones act these long motor but that's not really true. The structure of a man really is the relationship of these various parts of So soft that what you have, really, is that you have you have three systems here. You have the bone, and then you have the intrinsics, and then you have the extrinsics. And it's the intrinsics that mediate between your extrinsics and the bones themselves. They provide the structure to the body by providing the proper relationship."
A senior practitioner at Big Sur 1973, naming the three layers — bone, intrinsics, extrinsics — and the mediating function of the intrinsic muscles:
The zero point: bony surfaces as reference, not as engine
Even in the fully developed tensegrity reading, the bones do not disappear from the practitioner's attention. They serve a different function: they are the reference points, the zero points, from which the practitioner works. Bob Hines articulated this in a 1975 Boulder discussion about how to teach the tensegrity model to new practitioners. The bones, he said, are where the function starts when you are establishing what a piece of tissue is doing. They are the fixed points that allow the tensional structure to be read. They are not what produces the function, but they are how the practitioner locates it.
"And the the main thrust of of the consecrated model is to consider the whole and not the part. Right. Bob Hines, you got some thoughts that apply to this? I've had a lot of them. One of the things that along the lines of Jack's thinking that occurs to me is that the zero points in establishing the function are the bony surfaces. When you come down to it you want to actually start the program"
Bob Hines, naming the residual role of bone in a tensegrity practice — as zero point, not as engine of movement:
The spine as a unit, not a stack
Ida's mature teaching on the spine carries the spacer doctrine to its full conclusion. The chiropractic and osteopathic traditions had each, in their own way, treated the spine as a series of bony segments that could be adjusted one by one. Ida rejected this as a misunderstanding of what a spine is. The spine, in her teaching, is not a series of bones; it is a unified mechanism running from sacrum to occiput, held together by ligaments and fascia and acting as a single structural unit. The individual vertebrae are spacers within that unit. They do not stack and they cannot meaningfully be adjusted one at a time.
"Well one of the things that impresses me experientially as well as as I try to invest that skeleton with some flesh Is the essential nature of the spinal, not the spine as such, but the spinal structure? It is again as though a body was something built around a spine. Now a lot of people have had this idea, the osteopaths have had it and the chiropractic have had it. But none of them have ever gotten out of their spine a unified something going along there. They always manage to have a series of bony segments and that's what they figure a spine is. Now this is not my concept and this is not the concept around which structural integration works. You have to get that picture of the whole spine, the whole spinal mechanism as a unit, as a unit of united areas. It is a much more sturdy sort of a concept than, for example, the chiropractic concept, where you simply have bones that you push around. And I'd like you to take this idea home with you and try to get more reality on it. As you yourself get more processing, you will understand this. It is quite impossible, I think, to understand this before you have had the kind of processing that puts these things together."
Ida in her August 1974 IPR lecture, distinguishing her concept of the spine from chiropractic and osteopathic concepts:
The unification of the spine is not metaphysical. It rests on the same anatomy that the chiropractors and osteopaths know: the long ligaments running along the spinous processes from sacrum to cervical region, the dorsal fascia, the deep paraspinal structures. What changes in Ida's reading is the relative weight given to these tensional structures versus the bony segments they connect. The bones are the spacers. The ligaments and fascia are the unity. The spine acts as a unit because its tensional structure spans the whole length, holding the spacers in functional relation to each other.
"There are long ligaments that are running down along these spinous ous processes that are continuous then all the way from sacrum up to cervical region. That was the one anatomical connection I could come up with in terms of a specific connection which I thought was sort of an interesting point. Well one of the things that impresses me experientially as well as as I try to invest that skeleton with some flesh Is the essential nature of the spinal, not the spine as such, but the spinal structure? It is again as though a body was something built around a spine."
A practitioner, naming the long ligaments that hold the spinous processes in functional unity from sacrum to cervical:
Why the spacer doctrine matters to the rest of the work
The spacer doctrine is not an isolated piece of theory. It supports the rest of Ida's teaching about how the body comes into balance. Because bones are spacers held by tension, every structural change in a body is achieved by reorganizing the tensional web. The work of the ten-session series is, from this angle, a sequence of progressive tensional reorganizations, each of which leaves the bony spacers in different positions because the fascial planes around them have settled into different lines of stress. Ida's whole concept of stacking blocks — of getting the centers of gravity of the major body segments aligned over each other — depends on this view. You do not stack the blocks by pushing the blocks. You retension the web that holds the blocks and let them settle.
"The left side pulled down in order to pull the right side up. And the same thing was true of the front and the back. A body is rather like that. There are other things to realize about a body. It's not a squat single thing like a tent pole, like a tent plus tent pole. It's more like a series of blocks and those blocks need to be stacked. And you people all realize that you were all of two years old when Uncle Joe gave you some blocks And it didn't take you very long to know that if you were going to get a stable stacking of blocks, you could only stack it in one fashion. And we'll see a little bit more of that in the pictures that I'm going to show presently. The centers of gravity of each block had to be in a vertical line with the center of gravity of the block above and the block below before it was possible for those blocks to form a stable form. And this is part of the story of bodies. All bodies can be looked at as being aggregates of blocks, big blocks I mean, blocks like the head, the thorax, the pelvis, the legs."
Ida at Topanga, extending the spacer image into the stacking-blocks image and naming the relationship between them:
There is one further consequence, more far-reaching than the immediate practical implications. If bones are spacers and the tensional web is what carries and moves a body, then the practitioner working on a body is working on the structure that holds the body in space. Ida insisted on this throughout her career: structure means relationship in space, and the fascial system is the organ of that relationship. The body, in this reading, is a tensional unity of which the skeleton is the spacing apparatus. To change a body is to change its tensional structure. Everything else follows.
See also: See also: Big Sur Advanced Class 1973 (SUR7309) on the embryological development of connective tissue from the least-differentiated mesodermal cells, and on fascia as the matrix in which the cells live — a deeper biology behind the doctrine that the tensional web, not the bones, is the body's organ of structure. See also: Big Sur 1973 Tape 15 (SUR7329) on how the joints stabilize through deeper layers as the recipe progresses, with the bones acting as spaced units within a tensional core. See also: Open Universe 1974 (UNI_043) on the fascial web as the receptive interface between the body's energy fields and the practitioner's hands, and (UNI_044) on the experiential phenomenology — warming, melting, movement between layers — by which practitioners feel the tensional web reorganize during a session. SUR7309 ▸SUR7329 ▸UNI_043 ▸UNI_044 ▸
Coda: the bones get the credit they do not earn
There is a final observation worth making. The grade-school picture of the skeleton standing on a pedestal in the biology classroom is responsible for an extraordinary amount of bad anatomical reasoning. It looks like a building. It seems to imply that bones do the structural work. Generations of students have grown up assuming, as Peter Melchior assumed for years before he questioned it, that vertebrae are stacks and femurs are pillars. The Boulder transcripts of 1975 record the moment when a small group of practitioners worked out, in conversation with Ida and with each other, that this picture is wrong — that bones in a living body are passive spacers, that the tensional web is what carries and moves the structure, and that the practitioner's hands work the web, not the bones.
What remains striking about this conversation, almost fifty years later, is how unfinished it is. The senior practitioners did not pretend they had a closed theory. They had a working hypothesis, a set of beautiful models on the table, a body of practice that worked better when they thought this way than when they thought the other way, and a long list of unsolved problems — the lumbar gradient, the vertical lower leg, the curved rib. They held the doctrine honestly. They taught it as a reorientation rather than a creed. The page you have just read is an attempt to preserve that honesty: the spacer doctrine is the position Ida and her circle worked from, the practice consequences are real, and the anatomical questions remain open.