Your body is a miracle of engineering, physics, chemistry, and electronics. These
combine to form what humankind has not been able to duplicate, and probably never will.
Understanding spinal biomechanics requires understanding how the spine is constructed. The
spinal cord is an extension of the brain and together these tissues are encased in protective
calcium and phosphorous laden bones that we refer to as our skull and spinal vertebrae. These
vertebrae stack on top of one another, separated by donut-shaped cushion called “discs”.
These bones and discs must be anchored in place, yet still allowing motion. So, the body utilizes
strong, elastic ligaments to maintain the form of the spine. This structure provides an ideal
anchoring site for all of the powerful postural muscles that allow us to effectively move against
gravity and perform our everyday tasks. Your spine is designed to work for at least 120 years
when properly utilized!
I can hear you asking “Dr. Brack, that’s very informative, now what does this have to do
with our everyday posture?” The answer is summed up in one word: Plasticity. “Plasticity” is
the body’s ability to adapt and conform to the tasks and functions most often performed on a
daily basis. Over time weight lifters develop stronger muscles and bones, gymnasts develop
increased elasticity of muscles and ligaments, and individuals who earn a living while seated
find it harder to keep moving throughout the day.
When you look at a spine from the front, it should be straight; from the side, it should
have three important curves that form an “S” shape that help stabilize the spine and dissipate
the forces of gravity. There should be an elliptical curve in the neck and low back, and an oval
curve in the mid-back. Re-imagine yourself as an infant crawling around and holding that head
to examine the world around you. That is the natural position for developing these curves; in
this crawling position you can visualize the elliptical curves in the neck and low back drooping
down towards the floor and the oval curve in the mid-back facing upwards where the arms
support the trunk. The plasticity of our tissues allow our bodies to develop these curves over
time. When we finally start walking on two legs, the elasticity of these tissues helps maintain
the spine in this ideal form. Problems arise when we chronically and repetitively perform tasks
and assume body positions that antagonize this normal structure, forcing our bodies to adapt,
with our spine and nervous system suffering the consequence of spinal degeneration, bone
spurs, disc and nerve complications, and loss of function.
There is no particular chair or workstation that is ideal for everybody, however,
understanding and visualizing your normal curves will help you tailor individual solutions. . The
ideal sitting posture mirrors this crawling posture but in an upright orientation. While working
from this position, it is vital that we take measures to promote and utilize these beneficial
curves. GENTLEMEN: STOP SITTING ON YOUR WALLET. Sitting with objects in your back
pockets creates improper curves in the spine and leads to spinal degeneration with resulting
low back and hip pain. To support the curve of the lower spine you should try adding a
comfortable, elliptical-shaped pillow or support that fits into your natural spinal curve. Bigger is
not better, it is important to find a support the fits within your natural curve without distorting
it.
A way to have the correct head and neck posture is to make sure your keyboard and
display are centered, allowing you to access resources without turning or rotating. The screen
should be placed at eye level while your chin remains parallel to the floor with the ears in a
straight line over the shoulders. Placing books under the monitor is a quick solution. As the
chin drops towards the chest or begins to jut forward the natural curve in the neck is reduced
from a highly supportive spring design to a straightened “ramrod” configuration. This increases
pressure on the discs and spinal nerves leading to spinal degeneration along with symptoms
such as headaches, head/neck tension, numbness/tingling in arms/hands, vision changes, etc.
The “S” shaped curve of the spine is designed to effectively bear the weight of the body
while the muscles are designed to hold and maintain the spine in this position. Our bodies are
designed for movement which is the only way our spines and discs exchange nutrients for
functioning and repair. Sitting for more than an hour suffocates this nutrient supply to your
supporting structures and would be like running a marathon without breathing! A simple 5minute walking break every 45 min will make a huge difference!
Exercising prevention is paramount to the health and longevity of your spine and central
nervous system!
-Brack Burris, D.C.