Photo Credit: Tom Rouse

Lower Back Pain (LBP) is becoming more and more prevalent. Most of us at some point in our life have experienced back pain, or at least know someone that has. About 80% of adults experience low back pain at some point in their lifetimes (2). LBP is ranked as the third biggest contributor to health loss in New Zealand (1), and once you have had an episode of back pain you have a 30% chance of having a further episode within a year (3). These figures underline the massive impact that back pain has on the population, and highlights that our current management approach isn’t as effective as it could be.

With figures like these it can sometimes seem like an inevitability that you will get back pain, and that we are all doomed to a lifetime of pain and suffering. At Sports Lab we don’t believe this is the case. Over the coming weeks we are going to be discussing a variety of aspects of LBP, with an emphasis on disc injury.

There will be a recurring theme throughout the coming weeks. This is something we strongly believe in- MOVEMENT IS KEY. Our first piece of advice for anyone who is currently struggling with LBP, or even anyone that isn’t, is to keep moving! Find any movement or activity that you can do without increasing your pain and do it. That might be walking down the length of the driveway, getting on the floor and playing with the kids, or going for a 10-minute swim. The duration or activity itself doesn’t matter, it’s the movement that’s key. If you struggle with this, give us a shout and we can point you in the right direction.

For our first in this series, let’s explore the topic of slipped discs…

Slipped Discs

This is something that we hear a lot about and a topic that receives plenty of attention in the media. At Sports Lab we get numerous patients asking whether they should do an activity because of their slipped disc. We also hear from people who have “slipped a disc 20 years ago” so that is why they can’t play the sport that they love. But maybe this isn’t the right way to be looking at it.

Our discs are strong spacers between the bones (vertebrae) in our back. They are made of strong collagen fibres that attach directly to the vertebral body (via the cartilaginous end plate) and are designed to help with load distribution. These strong attachments to the bone do an excellent job of distributing load. When tested in isolation (removing all the other muscles, ligament and support structures) discs on their own take over 700lbs to compress by less than 1mm. (1) I think we can agree that they are strong!

The collagen fibres that make up the disc can (like any other structure in the body) be injured, but we argue that discs don’t “slip”. Now I know that some of you will be thinking that it is just different wording for the same problem. But terminology is important. If we label something “slipped” it gives the impression of a highly mobile structure gliding about all over the place. It suggests that at any time the disc can slip and that reinjury is almost a given. Luckily, this isn’t the case.

So, if our discs don’t slip what happens to them?

We can have varying degrees of disc injury which relate to the degree of structural dysfunction that occurs to the collagen fibres. The disc is made up of; the annulus fibrous, the thick fibrocartilage outer layers, and the nucleus pulposus the gel like inner collagen matrix. Disc injuries are classified dependent on the degree of damage to the annulus fibrosus and the involvement of the nucleus pulposus. Sequestration, extrusion, protrusion, and bulge are the terms used when discussing the severity of disc injury. Sequestration is the most significant, with bulge the least.

We now know that we don’t “slip” our discs, but that we can injure our discs. The next thing to look at is healing of the injured disc. Keep an eye out for next weeks blog that looks at just that.

References
(1) National Health Committee. 2015. Low Back Pain: A Pathway to Prioritisation. Wellington: National Health Committee.
(2)
https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Low-Back-Pain-Fact-Sheet
(3) Silva, Tatiane & Mills, Kathryn & Brown, Benjamin & D Herbert, Robert & Maher, Chris & Hancock, Mark. (2017). Risk of Recurrence of Low Back Pain: A Systematic Review. The Journal of orthopaedic and sports physical therapy. 47. 1-27. 10.2519/jospt.2017.7415.

Richard Linley is a senior Sports Lab Physiotherapist. He has extensive knowledge in major trauma, and both acute and chronic care. There’s a myth that Rich is also a vegan.