Why Is The Spine So Prone To Injury?
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.
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.

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).