Explainer: What is the ‘Slipped’ Disc Myth?
A study published in the Medical Journal of Australia in 2015 confirmed that Australia’s workplace productivity is crippled by back pain; back pain impacts up to 70% of Australians annually, costing over $14 billion a year in lost productivity.
Many of us have heard our colleagues and close friends complain about back pain, and the term ‘slipped’ disc is a regular feature in our vernacular. And yet the label of a ‘slipped disc’ is a misnomer- back pain can be severe and debilitating, but the discs in our spine cannot actually ‘slip’.
Understanding your Spinal Column
Despite the prevalence of low-back pain in Australia, the causes, symptoms and treatments of it are widely misunderstood – which means that many patients don’t know much about what is causing their pain.
Your vertebral column (or spinal column) is made up of 24 movable vertebrae, and between them, 23 intervertebral discs- usually just referred to as ‘discs’. These discs are made up of metabolically active tissue, and they act as a ligament to hold the vertebrae together. The structure of a disc consists of an outer fibrous ring, which surrounds an inner gel-like center. A healthy disc can do many things: it provides some structural integrity to your back, while also allowing some movement of the spine. Our discs serve as shock absorbers, while also helping to exchange fluids and nutrients between the vertebrae and the disc.
So if Discs don’t ‘Slip’, what happens to them?
As we age, the gel-like centre of our discs start to change from a consistency similar to toothpaste into a more hardened substance like window putty. Disc ageing can often lead to degeneration; as discs lose their water content and become more fibrous, they become more stiff and brittle. Disc degeneration can alter the disc height and the mechanics of the rest of the spinal column, often adversely affecting the behaviour of other spinal structures such as muscles and ligaments. Discs often fail when people repeatedly move them incorrectly with poor sitting, moving and lifting postures.
The most common disc disorder is herniated or prolapsed (bulging) intervertebral disc. Injury or weakness can cause the inner portion of the disc to protrude through the outer ring; imagine holding either a jam doughnut or monte carlo biscuit and squeezing down on it between your thumb and forefinger.
‘Bulging discs’ are often associated with ageing, and can vary in severity. A severe disc bulge can be extremely painful, and is associated with muscle spasms and referred pain down the leg. Rare cases can cause ‘foot drop’ (paralysis) and loss of bowel and bladder control- this is a surgical emergency. ‘Herniated discs’ are slightly more serious, and can cause significant low-back and referred leg pain which is often sharp and shooting. This occurs when the disc compresses one of your spinal nerves; the initial severe pain is partly due to the body’s immune response from bleeding tissues where the disc material has bled into an area that is not used to having that type of protein fluid in the area. During these first days of the injury it is very hard for patients to get into a clinic, so 48 hours of rest at home is recommended. After that, clinic based treatment should begin.
Fig 1: Disc Degeneration
Want to know more about discs? Ask your chiropractor at your next appointment!
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