Tensegrity is a term coined by Buckminster Fuller and is a contraction of the two terms tension and integrity.
In the body, tension is controlled by muscle activation. Tension, when appropriately applied:
In other words:
In a structure that is held together (and integrated) by tension, the tension elements are all connected, as in a network, so that they can share and distribute tension instantaneously (or as much as possible given the constraints of the material that holds the tension).
So that tension is distributed freely and adjusted freely within a tensegrity, the space creating elements (also called "compression" elements) can move relative to each other.
The amount of movement isn't necessarily a lot, but it is enough that solid "spacers" have enough room to move relative to each other so that tension can be efficiently redistributed.
There are two main types of elements in a tensegrity model:
In a tensegrity model of the body bones don't directly contact or press against each other.
They are held together by the joint capsule, which in turn is an extension or modification of the connective tissue network.
The fluid within the joint pushes outwards on the connective tissue envelope and the ends of the bones it connects, and helps the ends of these bones to move or adjust relative to each other.
This allows the joint to "self-adjust" or "self-tune".
The joint capsule keeps the bones in the needed relationship, but within the confines of that relationship the joint capsule allows the bones room-to-adjust, to get comfortable.
In the ideal, the joint always adjusts so that all the various tension components share stress so that no component is over stressed.
Tensegrity models often look like cubes (or tetrahedrons) made up of rods held together by string or wire (or occasionally elastic.)
These models can be dropped or bounced and remain intact while still retaining the relationship between the rods.
The relationship between the rods remains intact, i.e. parallel rods will remain parallel to each other. However they do not come in direct contact.
Occasionally the abilities of a tensegrity to withstand stress are exceeded and a tension (or spacer) element will break.
And so while acting as a tensegrity can make our body resilient, it still can be damaged.
How then is the injury compensated or covered for to allow for recovery?
Our body may be modelled as a series of overlapping Potential Tensegrity Structures.
If a tensioning element (muscle, ligament or tendon) is damaged or injured, other tension elements tighten up to protect the injured part where possible.
Pain may result from exceeding the limits of these muscles to protect the injured area. It can also result from these "protective" elements being overworked.
Sometimes, or perhaps, oftentimes, even after an injured tension element has healed, the body still acts as if the healed part is still injured.
Pain may result not from the injury but from muscles that are forced to work unnaturally because they are still compensating for the muscle that was injured.
At least that is my understanding.
I bring up the idea of tension and tensegrity here because not only is it important in maintain integrity throughout the body, it also provides one of the means by which we can feel our body and control it.
In the case of old injuries and old no-longer-needed compensation patterns tension or its lack can allow us to feel where muscles and connective tissue have tension or don't. It gives us a method for fault finding our own body.
We may not even have suffered an injury for our body to operate less than ideally. It may be the result of habits learned from the work we do or the people we spend our time with.
By learning to feel tension and adjust we can learn to take control of our own body.
The tension that creates tensegrity is present in muscle fibers when those muscle fibers are active and in the connective tissue within a muscle when the muscle is relaxed.
And it is present in tendons and ligaments.
This tension is something that we can learn to sense and with the right amount of tension it is also something that we can use to better control our body.
With the right amount of tension, not too much and not too little, i.e. with the slack removed, we can make changes instantaneously.
There is a balance between too much tension and not enough of it.
Too much tension, particularly when it is the result of excessive muscle tension can deaden sensitivity unless that sensitivity is well developed in the first place.
Another reason for not using excess tension is that it is in-elegant and wasteful.
If you have ever seen kung fu movies where some kung fu master dispatches foes with ease, it is because he or she is using minimum effort, minimum tension to do the dispatching. And he or she is also sensitive, aware of both themselves and their opponents(s) and because they have enough training that they can respond automatically to most sorts of attacks without having to think.
My own kung fu teacher demonstrates this regularly.
So when doing any exercise or pose with tensegrity as the goal, focus on relaxing as much as possible, on doing movements or poses with minimum effort.
At the same time focus on creating maximum space.
And balance these two ideas with the idea of being able to feel your body and respond instantaneously. This means having not too much tension, but also not too little.
To get to this stage it helps to move between the extremes of complete relaxation and maximum tension.
By moving between these extremes (within a safe range of maximum tension) we can learn to recognize when we've achieved optimum tension.
This is very much like the process of tuning a stringed instrument, moving either side of the desired note and gradually zeroing in on it.
My first exposure to the above principles (feel and control, balance between space and tension), was when first learning partner dancing.
The lead had to be stable and firm enough that their intentions could be easily transmitted to their partner.
The partner also had to be firm enough so that they could receive inputs from their lead.
In order to dance well both partners had to "listen" and both had to be able to respond.
The main difference is that the lead chooses what to do, then he transmits the choice to the partner so that the partner can follow.
The choice could be limited by the position they are currently in and by the amount of space they have around them. And so the lead also has to be attentive and responsive. And so in a way he isn't necessarily choosing, he's seeing what options are the best given the present circumstances. And so they respond.
And that's the way we can do yoga, whether stretching or strengthening. We can tune into our body, via tension (and it's lack) and respond.
One way to build "tension" awareness is to practice moving. In the context of stretching postures and yoga poses, that can mean moving into and out of a pose or position.
The key to building awareness, while repeating an action, is to move slowly and smoothly with focused awareness.
To get a feel for this try reaching an arm up over your head as quickly as possibly. It could feel like you are snapping your joints into alignment making your elbow straight and suddenly pushing your shoulder blade upwards.
Next do the same action but moving slowly and smoothly. Which feels better?
If you aren't sure repeat the quick movement a few times and then repeat the movement slowly and smoothly while focusing in turn on feeling your shoulder (lifting), your elbow (straightening) your fingers (palms spreading open, fingers lengthening and spreading apart.) Then slowly relax and repeat.
Which feels better? Which leads to a more meditative comfortable state of body and mind?
In general I tend to find the slow and smooth movements feel nicer, nice enough to the point that moving slowly and smoothly is its own reward because it feels good.
That being said, when first learning a movement, it may be rough and/or quick and probably not very smooth.
That's okay. Once you have an idea of the basic movement then work towards gradually activating and gradually releasing.
And repeat the movement so that you get used to the feel of it as well as controlling it.
While we may not always want to move slowly, I'd suggest that the smoothness is something we can carry into fast movements.
After practicing moving slowly and smoothly, we can maintain the tension, and the feel and control of our bodies while moving faster.
Movements may start of rough and not very controlled, but after a few repeated movements in and out of the pose, you not only get familiar with the pose but also your body.
And so that you can learn to feel changes in tension, focus on the part that is moving. Or focus on the part of your body where there is a change in sensation.
You can then calibrate that change in sensation to what is actually happening.
If you've ever tried to stretch an elastic you know that you can't pull on one end to stretch it unless the other end is fixed. The same applies when applying tension to the body. It helps to have one end, or some part of the body fixed or stable.
How do you make a part of the body stable? By making it bigger or heavier or by adding tension (by creating space.)
How do we "lock" two parts together so that their shared mass acts as a foundation? By adding tension on two sides. This tension can be created by working against opposing muscles or by one set of muscles working against gravity.
For most actions of the shoulders, the ribcage, neck and skull form the foundation.