The Intelligent Body

The Bones are the Prime Movers

This interview is a summary of conversations held with Dr Stephen Levin, recorded by Elisabeth Davies, immediately following his participation in the "Intelligent Body" conference.

Following your presentation at the Intelligent Body conference, could you say a bit more about linear and non-linear systems?

Linear systems obey the common Newtonian laws of physics. They are usual in non-biological systems. If you introduce a stress into a non-biological system, as you increase the stress, the strain (the deformation, or resistance) will increase in equal measure, giving a straight line on a graph. Hence the term linear. However, if you introduce a stress into a biological system, this line will not be straight, but curved. As you introduce the stress, it is at first absorbed by the "give" in the system, so that initially the line stays almost horizontal, but as the stress increases, the system stiffens in resistance, becoming increasingly strong as the system is loaded. This exponential increase gives a curved line (the stress/strain, S/S curve) instead of a straight one, which becomes steeper until it is almost vertical. You can demonstrate this with stretch or compression. A linear spring springs back with equal force. If we functioned like that, when we run we would bounce up in the air as if we were on a trampoline. A good example of a non-linear spring is the earlobe: pull it down and you can feel the resistance increase to the point of limit (the steep part of the non-linear curve). Release it - it doesn't snap back in the opposite direction, but just goes back into place. If we look at compression, when a weight lifter reaches his limit, he's at his strongest because his system is at its tightest. This makes non-linear systems much stronger than their linear equivalent. It explains why weight lifters don't explode, as Newtonian laws would have them do, long before reaching their biological limit.

And this non-linear stiffening comes from tensegrity.

Yes. On this model here (a "tensegrity truss" with six struts suspended in a network of tension wires), when you shorten (by twisting) any one of these wires, you can see that the whole structure expands. Tighten one element and you tighten the whole network. It becomes stiffer. This is what happens under load. The greater the load, the stiffer or stronger the structure. This is true of any tensegrity structure, and it is true of the body, however light or heavy the load. Pick up that pencil there. What do you feel in your body, your diaphragm, your legs? The whole thing tightens up. The whole organism increases tension throughout the network, though if the load is light we may not notice this. The opposite extreme would be the weight-lifter. Before he lifts a weight, he breathes out and contracts his whole body inwards towards the centre. Then as he lifts the weight he expands.

You said that in truss systems such as the biotensegrity (TM) model there are no bending moments, no shear and no torque.

Right. Within the truss itself, there is no bending moments, torque, nor shear. They only occur at the interface. My interface is with the ground. In the giraffe's neck, when it stretches out horizontally, there is no shear, only increased tone in the balanced tension and compression in the tensegrity of the body as a whole. When you pick up that cup of tea, your wrist doesn't shear. But because your interface is the ground, your muscles will always pull you towards that. They always pull you to the ground. You can't pull yourself up by your own bootlaces. Even when you bend down and lift something up off the floor, you are really pulling down. And your relationship with the ground obeys Newtonian laws.

If non-linear systems don't obey Newtonian forces, why do I feel shear and torsion in my patients?

In treatment, your contact with your patient also has Newtonian laws. It's the meeting of two tensegrities. The interface. You are using your tensegrity to guide theirs. But there would be no shear or torque within their system.

Why then do I sometimes feel force vectors in my patients? If there has been an impact, it can feel like a fulcrum somewhere inside or outside the body which is limiting motion.

There is no fulcrum unless you create one with the structure. You may need to change your terminology and say something like "reference point".

Another question directly relevant to what we teach: Sutherland said that the ligaments guide and limit the motion of a joint and also act as agents of correction. We utilise this potential when we apply Balanced Ligamentous Tension techniques to any joint in the body. Have you observed this and can you offer an explanation for why it takes place? There is very little in the literature about the proprioceptive function of ligaments.

It has to do with energy requirements. The 'play' of a joint is at the lowest (flat) part of the S/S curve and what you have done is to help the body seek that level. The 'balanced ligamentous tension' that you feel is when the joint is at its lowest energy point and you have helped the body make the more perfect, symmetrical tensegrity.

In your presentation, you said that the joint surfaces never come into approximation. How is this possible, especially under extreme circumstances such as weight-lifting?

It is quite possible, as long as there is no loss of structural integrity. In the biotensegrity model, under normal circumstances, the bones are all floating compression structures, and don't come into contact. All the compression elements are held apart, they don't touch. But if you cut the tension elements (the ligaments) the bones come together. The articular surfaces of joints are not under compression unless there is some soft tissue degeneration.

I understand the principle, but if I take a joint such as the knee, I find it difficult to see how this works in practice.

The mistake is to look at any one joint in isolation. You have to see the whole system as a heirarchical system of icosahedra, small ones inside larger ones. When you look at a knee, it is hard to tell which precise parts of it provide compression and which provide tension. But whether it is under load or not, the synovial fluid is under minimal pressure. This has been measured. The compression on the fluid is nowhere near the amount of pressure needed to keep the two surfaces apart. Something else is holding them apart - the opposing forces of compression and tension in the tensegrity of the whole limb and of the body as a whole. The tensegrity may not be local - it may be in the interactive co-operation of several joints. You can't treat a joint in isolation. Joints are subsystems of a metasystem.

Does this only apply to joints?

No. It applies to the whole system. The kidney, all the organs, work the same way. Look at the sesamoid bones underneath the first metatarsal. They never touch it. They're soft and squishy, and would smash with every step if they were under load. The kneecap works the same way, it never touches the knee.

What is under compression then?

The bones. The bones are the prime movers.

... The bones are the prime movers? Not the muscles?

The muscles may initiate and modify movement, but once movement such as walking, running, cycling, has been initiated, the bones would be the most efficient prime movers. Principally the shafts of the long bones, the compact bone. The collagen is arranged in spirals of stacked icosahedra, and the hydroxyapatite crystals are also icosahedra and they just snap into place making a complex of protein and crystal. This makes the stiffest structure in our bodies. The stiffer the structure, the more energy it can absorb. The spirals in the bone give a soft landing that stiffens quickly. The energy of meeting the ground is stored in the bone. Once the energy has been absorbed it has to be released in rebound or the bone would get hot. As the energy is released, it springs like a non-linear spring, propelling you forward. This is the most efficient way of using energy. By the way, the fibula is exceedingly strong.

I seem to remember you saying that the ligaments provided rebound too.

They are the next stiffest structure, so they also provide rebound, but less. The muscles are the dampeners, more of a control thing. There are more muscles in the body, so they have a kind of bulk action. The greatest compression forces are absorbed by the bones; the greatest tensile forces are borne by the ligaments. The strongest ligaments in the body are the sacro-iliacs. They are strong at birth. So are the cruciates. The stresses in utero create the strength. Likewise the development of bone in utero is the result of the mechanical forces present.

So once the muscles have initiated the movement, are they completely passive?

To be the most efficient, they remain in isotonic, isometric balance. Take the quads and hamstrings for example. As you flex the hip and bend the knee simultaneously, the quads remain the same length. Likewise the hamstrings. Imagine you are preparing a cyclist for the Tour de France. Every last adjustment has been made to his bicycle, for optimum performance. His job is just to increase his overall tone, to just the right level, just like when I twisted the string on the tensegrity model. When you contract a muscle you squeeze the bone, put energy into it, increase its tone. When they train for the Tour de France, they hook up all the muscles to an EMG and set the tone to the perfect level of tuning, then all the cyclist does is let it oscillate. All things under tension vibrate and oscillate. Then he does some small slight thing to initiate action, to initiate the oscillation, and off he goes. After that there's no need for added contraction from the muscles, they just remain at that level of tone, and work like the spokes of a bicycle wheel. And he adjusts the tone and frequency of the oscillation according to the terrain. The goal is minimum effort to sustain isometric and isotonic balance. Energy input comes from various things - gravity, inertia - and it's the bones that provide most of the rebound which propels him forward.

Is this what we mean by being "in the zone"?

Yes. You can apply it to the martial arts, musical performance, and so on. It happens in the flat part of the non-linear curve. You can set the tone to different levels. In peak performance you have raised tone but minimal energy expenditure. The greater the tone, the quicker the response time. This means the non-linear curve rises quicker, but you still have that level part first. When you people talk about still points in treatment, I think you are operating in this same flat part of the curve, but maybe prolonging it. However, it can never get completely still, you never stop oscillating.

When cyclists train, you said that just the right amount of tension was necessary. And earlier you said with a slight amount of tension, the structure expands. But you also described the weight-lifter contracting his body and breathing out before lifting. Is there a switch-over point at which the body goes from expansion to contraction?

Energy transfer, again. Play with a model. There is a resting state of balanced energy, compressing it (energy input) stores energy which is then released as it expands, going past the resting state (which is in energy balance of tension and compression) requires energy etc..

I remember you saying that tensegrities are natural oscillators. Am I right in thinking that an oscillation is a transition from one state to another and back again?

Yes, it's a transition from a low energy state to a high energy state and back again, between open and closed structures. Everything in you is oscillating. You can apply it to any alternating states, from the beating of your heart, to respiration, to the gel-sol transition such as in synovial fluid - as I illustrated in my lecture, with shaving cream. In its resting, low-energy state, a gel consists of icosahedra, which are relatively - but not completely - stable. As stable as you can get. Compress it, and the icosahedra move into a transitional state which is cuboidal, less stable - it's a high energy state - it takes more energy to maintain it (triangulating the corners of a cube gives a cuboctahedron, which is closely related to the icosahedron in structure). This less stable cuboidal form collapses like a house of cards, allowing the gel to shear, become sol. Now you can smear it around. Remove your hand, releasing the compression, and it converts back to its low-energy icosahedral form. That's a great model. Whatever the energy input, the icosahedra will seek the least energy (more stable) form for that..

Is the oscillation always between these two forms of icosahedron and cuboctahedron?

The best answer I have is a quote from Buckminster Fuller: "The vector equilibrium is a condition in which nature never allows herself to tarry. The vector equilibrium itself is never found exactly symmetrical in nature's crystallography. Ever pulsive and impulsive, nature never pauses her cycling at equilibrium: she refuses to get caught irrecoverably at the zero phase of energy. She always closes her transformative cycles at the maximum positive or negative asymmetry stages. See the delicate crystal asymmetry in nature. We have vector equilibriums mildly distorted to asymmetry limits as nature pulsates positively and negatively in respect to equilibrium. Everything that we know as reality has to be either a positive or a negative aspect of the omnipulsative physical Universe. Therefore, there will always be positive and negative sets that are ever interchangeably intertransformative with uniquely differentiable characteristics." Synergetics, 440.05. A full discussion of this is in his book that can be found on the web: http://www.rwgrayprojects.com/synergetics/toc/toc.html. The icosahedron is a stucture that is fully triangulated, symmetrical, omnidirectional, closest packable, has the largest volume for surface area. It is not the lowest energy structure, (a tetrahedron is but it lacks some of the other properties such as being omnidirectional). Biologic structures will always vacillate between the vector equilibrium, which doesn't ever really exist but is an energy state, and the icosahedron.

When we work with the involuntary system/primary respiration, we are aware of a change of state, like an inhalation and exhalation, throughout the body, varying from two and a half to ten times a minute. This must be an oscillation. Could we apply this changing state from icosahedron to "vector equilibrium" to this also?

The base string oscillates at a different frequency than the violin string. Each sub system-system-meta system will have its own frequency. The respiratory system is an oscillating system on its own but also part of the whole.

You said that icosahedra are self-generating, that they self-assemble. Could you say a bit more about this? From what do they self-generate, for example in the case of structured water.

The self generation and self assembly is related to closest packing and the laws governing foams. What makes a bubble the shape that it is? Those laws govern the shape of cells and structures.

If I try to assemble icosahedra into a close-packed model, there are still gaps in between. In the body, what would fill these gaps?

Vacuoles, water, fractals. The forces that change the shape become part of the energy input-release and oscillations.

Finally, have I understood you correctly in saying that the laws of physics can answer all conceivable questions and that there is no need for a mystical interpretation. What about quantum physics? Is tensegrity a kind of bridge between the "normal" and quantum worlds?

If you attribute some mystical qualities to an event then you stop seeking what may be a simple physical property. For me, at this point in my life, the laws of physics are mystery enough and that is where my mystery stops. I leave it to the physicists to try and demystify those.

So how would you suggest we interpret some of the more mystical experiences that some of us have from time to time in treatment?

Information and energy transfer is at non-conscious cerebral levels, but this doesn't make it mysterious - it's a physical thing. The shaman gives quinine and does a dance, and we think the dance fixed the malaria. The miracle is the physical laws - why do I need other miracles? If we fully understand these laws we can use them more intelligently. The laws of physics are the laws that shape our world and its behaviour. I recommend an article by Harold Kroto called "Space, Stars, C60 and Soot" (Science, 242, 1139-1145 (1988)). Biologic organisms are not just bags of chemicals and electrical charges, but physical structures that obey physical laws. Organic chemistry, from the benzene ring to the most complex protein and assemblages of protein, is physical chemistry. The assemblage of chemicals that compose a biologic organism is a physical process. D'Arcy Thompson (1860-1948) said in his book "On Growth and Form": "Cell and tissue, shell and bone, leaf and flower, are so many portions of matter, and it is in obedience to the laws of physics that their particles have been moved, moulded and conformed."

Elisabeth Davies, May 25 2005