What is Causing the Pain??
Your spine must be stable to support upright posture, and also
flexible, allowing you to bend and twist. This is mechanically very
challenging and makes your spine vulnerable to injury. The spine is made
up of a chain of bones, called vertebrae, which are connected together
by ligaments and muscles. The vertebrae cover and protect the spinal
cord, which carries sensory messages to and from the brain, controlling
all your body functions.
A disc separates each vertebrae and acts like a cushion, absorbing
shock along the spine. The disc is made up of jelly like substance known
as the nucleus, covered with many strong outer layers called the
annulus. The discs do not have a supply of blood vessels to nourish and
replenish them, rather, they depend on a transfer of fluids, nutrients
and oxygen from the bones (vertebrae) above and below them. This
transfer of fluid depends on the difference in pressure between the
inside of the discs and the surrounding vertebrae and blood vessels.
This is why most disc nutrition and regeneration takes place when we lie
down and the pressure inside the discs is reduced. This process is not
very efficient, and as we age, the disc is exposed to wear and tear
greater than its ability to heal and regenerate.
The discs are prone to injury and degeneration as we use our backs each
day, as they are compressed and torqued through sitting, bending and
lifting. In the two lower levels of the lumbar spine, stress forces can
equal 2,000 to 3,000 pounds of pressure per square inch. Repeated injury
weakens the annulus, while the earliest changes that occur in the discs
are tears in the annulus. With increased pressure inside the disc, the
tears in the annulus may allow the disc to bulge like an old tire with a
broken casing. Any internal damage to the disc may cause severe pain in
the back. If all of the layers of the annulus break, the jelly-like
nucleus will ooze out of the disc, causing a disc herniation. A bulging
or herniated disc may press on spinal nerves, causing sciatica, which
can be felt as weakness in your muscles, loss of sensation in the skin
or a tingling or burning sensation along the nerves in your buttock and
legs. Repeated episodes of injury results in the degeneration of the
disc, which becomes stiff and dry, causing it to lose its shock
absorbing properties. This process may continue until the disc is
collapsed, which increases the mechanical pressure on the bones and
joints lending to arthritis (facet syndrome).
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