Why it Matters: Posture,
Alignment & Tensegrity
This article assumes some knowledge discussed in the article on connective tissue & fascia.
"Sit up Strait" my dad used to bark at me, especially at dinner when I was a teenager. Ten years later as a young software engineer I was suffering from massive amounts of back pain that were beyond belief. On a journey to find a cure and source of my pain, I came to discover that my dad was right. Posture matters. Alignment matters. His insistence on sitting up strait was of tangible importance to my health. As parents often are: he was right... Sort Of.
Simply "sitting up strait" is not quite the complete solution. If it were that simple, there wouldn't be millions of Americans in chronic pain. As a matter of fact, commanding the body to sit up strait can lead to more pain. Trying to drill one's body into physical submission often leads to more stress in the soft tissue (muscles and fascia) and also such a radical adjustment in posture where one thinks about sitting up strait often leads to misalignments and pain in other parts of the body where one is focusing less attention, usually the low back or sacroiliac (sciatic nerve area).
More than the old fashioned, "sit up strait", what is tangibly important is how you sit- and for that matter how you stand, walk, read, live, enjoy nature, or exercise. Activity must be relaxed and free of tension. In other words, "sit up strait" but be relaxed as you sit. Tense "sit up strait" will not work, and for many relaxed "sit up strait" is impossible. Chronic pain is a symptom of imbalance, and imbalance is brought on by accumulated stress or tension: mental tension, emotional tension, and physical tension. We'll start by looking at the physical - gravity.
Check out our friend here,
Mr. Block. His anatomy is pretty simple. He is 2 dimensional, has 2
yellow torso blocks (or bones) and a head, he has 2 muscles b (back) and c
(chest) which give him mobility forward and back in a single plane of motion. Looking
at Mr. Block, he looks pretty balanced, pretty happy, good natured, and
easy going. You can see that "sitting up strait" (or standing, whatever
you want to call what he is doing) comes pretty easy and natural
for him. He is simply being. If he wanted to move himself forward he
could simply flex (shorten) muscle c. If he wanted to move back, he would
simply flex muscle b. This encompasses complete range of motion in his
simple two dimensional world of movement. But right here, in his natural state he
is tall, yet relaxed. His lower yellow block easily supports the upper
block with little or no muscular effort. Life is easy and simply
flows.
Then one winter, Mr. Block was shoveling
the driveway, a lot. There was lots of snow that year and he spent much of
his time vigorously "hunched over" shoveling. He was often in a hurry and
while shoveling, he
overstretched his back, b muscle while
his front c muscle was so tight, it left him a bit forward. It felt
a little 'weird' but didn't really hurt, so he lived on
and didn't think much of it. Pretty soon this alignment feels
normal.
Suddenly, a couple years later, Mr. Block started having serious back pain. It started for no apparent reason. Just started when picking a nail off the floor. It seemed odd that such a small, almost non-movement could cause such pain when he had moved so vigorously in the past without problems. He was told that his back just "went out." That his back could just suddenly "go out" --- that nothing was building to it --- seemed to somewhat defy reason and explanation, but there are many unexamined assumptions in the flatland of block people that simply make up the socially agreed worldview.
What happened to poor Mr. Block? He used to be on top of the world! (at least the flat 2-dimensional one). He overstretched his b muscle. The muscle didn't complain much at the time. After all, muscles have to stretch to allow for motion in the other direction, so the stretching wasn't really the problem. But look at Mr. Block's posture after the shoveling incident. His top block is clearly not stacking over his bottom block. As a matter of fact, without effort from his b muscle, the top block is pretty much going to fall over. This means that his back is engaged all the time just to hold him upright. Over time this makes his b muscle very hard and tough, the fascia around it, starved of nutrients dries out and hardens.
Mr. Block has noticed how tight his back is. He gets it massaged, which gives it temporary relief. But look at him. Scroll Up if you need to. Look at his back. While allowing the b muscle to relax will give it relief, it will still need to be constantly engaged to keep the top block from falling over after his massage is over. Without releasing the front c muscle to its natural length, the back will always be in pain because it is always working. Even if Mr. Block gets his c muscle massaged, simply working the muscle will not fix his problems because the connective tissue (fascia) around the muscle will have also shrunk and also need to be lengthened (see article). He will need to see a bodyworker who knows how to release connective tissue as well as muscle.
This happens for many of us. Maybe not because of shoveling, but because of the thousands of hours we sit in a car or in front of a computer, it may be emotional trauma that causes us to 'hunch' to protect our heart, or constant stress: physical and emotional. Our back may hurt like Mr. Block's or it may be a shoulder, hip, neck, or knee that's giving us fits, but most chronic pain has its roots in this principle. If the body does not align to gravity, as in the first picture of Mr. Block, whether it be by stress or physical habits, gravity will slowly act until your body can no longer compensate for its own misalignment: and the pain begins.
The permanent solution to chronic pain is to
re-align the body. The body has tremendous ability to compensate for
misalignment, but given enough time: chronic pain will persist until the
body is re-aligned. 
Chemicals
will not fix the problem. Surgery may complicate it. If Mr. Block
realizes this, he might choose to see a chiropractor to realign his
blocks. This might work very well. If so, good for Mr. Block - his
back pain will go away. Chiropractic is wonderful, it seeks to re-align
the body, which is vital, but for some it may not work. Others may dislike
needing constant and persistent re-adjustments. Note that if Mr. Block's
c muscle and surrounding fascia continues to be tight, it will pull his top
block back over after each time it is realigned. To remain permanently
realigned, the muscles and fascia must be taken into account.
If only we were as simple as Mr. Block. With two bones, a head, two muscles, and one dimension of movement, diagnosis is easy. Our bodies are much more wondrous and intricate. With over 200 bones, over 500 muscles, and nearly infinite planes of movement; we are billions of times more anatomically complicated than Mr. Block. While our spinal column plays an important role of support that is effected by gravity, alignment, and balance. It is not (at least when healthy) functioning purely as a "stack of blocks" compression structure. It functions as a tensegrity (tension + integrity) structure. This makes our bodies more resilient, more flexible, more adaptable, stronger, and more powerful, than anything built from the ground up. It also makes us very vulnerable to the maladies of misalignment.
Compression (stacking) is the way humans engineer buildings. It is not how nature grows its organisms.
Compression is a stack: One
on top of another. The higher blocks 'stack' on top of
the lower ones, squeezing or compressing them. The lower blocks have much more
pressure on them than the higher blocks. One would think, if our bodies were built
this way, one could hardly walk. Indeed if mother nature made humans on compression
models, this would true. A body built by only stacking parts on top
of parts would quickly fall apart and give out to the forces of gravity.
In reality, the body is built more like a domed tent where the bottom of the
tent is supported by the top (via hooking to the poles at the top of the dome),
and the top is supported by the bottom (via poles and stakes into the ground
).
There is lots of exciting, cutting edge work in biology on dicovering more and
more ways the body is put together as a tensegrity structure. This
wonderful model we've discovered from mother nature has even found its way into
our architecture. Many earthquake proof sky scrapers are built using a
spring-like load that gives the building resilience. This is tensegrity at
work. An ideal structure for the physical world.
For those curious, I keep a tensegrity model in
my office to show the resilience of this form. You can crush it, stretch
it, pull it, and it will always regain shape because the load is evenly
distributed throughout the entire structure, whereas the load in a compression
structure (a brick wall) is distributed mostly to the
lower bricks. Similarly, the load of our body is distributed up and down
the whole person. This is why a pull in the neck can effect your knee, and
a bad foot might cause back problems. 
Through the weave of pulleys,
levers, and stakes in the body's organic make up, the impact of trauma is stored
throughout the body, albeit in lesser concentration away from the problem
site. This makes us resilient to the blows life gives us
through the years, as a tree sways in the wind, but it also means that any chronically
painful or malfunctioning point also has its roots of dysfunction stored in
other places all over the body. A bad knee
may not be fixable without re-aligning the neck, upper back, and feet.
Tensegrity is such an effective structure that it
gives us a bit of a feeling of invulnerability. Our body has done such a
good job
of "evening" out the impact, that we don't realize that many
old impacts and injuries still live with us. We lose the understanding
that whether it is the pounding of strenuous sports or the pounding of sitting
still for hours on end, for days on end (which our body was not designed to do),
all of that impact adds up. We only notice it the day that 'our back goes
out' or our neck or hip start hurting. We only notice when the structure compromises.
Note that the Mr. Block example above is still quite accurate in terms of body structure interactions, movement, balance, and gravity. Tensegrity adds to the reality, that while Mr. Block's muscles and fascia are healthy, his lower block is not being totally compressed by the upper block. In fact the two are supporting each other (as the dome tent), but as his body loses elasticity, it will start to behave more like the brick wall and discs between his blocks will compress.
The tensegrity structure
pictured here would not keep it's resilience if one of the yellow sticks (bones)
broke or was misshapen. It would also be very vulnerable if any of the
elastic red bands (muscles, fascia) suddenly became too tight (hypertonic) or too
slack (hypotonic). Balance and proper structure is vital to the survival of this
model. It is also vital to the well functioning human
being. Mother nature knows her physics and uses the best support
structure for the physical world. Biology designs via tensegrity.
Any rebalancing effort must take this into account.
In all this is quite a lot of information to absorb and understand when you are new to it. It may make sense, but you may still be unsure of what it means to your body in particular. The basic concepts in the first three articles will be plenty sufficient in providing the foundations for the client and practitioner to communicate and get the client's body back closer to its natural, balanced, youthful, working order. Like any complex understanding, the education will accumulate over time and particularly experience. Starting with postural analysis and moving through bodywork and arranged yoga postures, the picture will become more and more clear to you, and you will contain the self tools needed to keep your body more in balance over the long haul.