Up to 90% of patients will recover from acute low back pain within 6 weeks, so this begs the question: do you need a scan before seeing your physio?
Scans such as x-rays, ultrasounds and MRIs have become commonplace in acute musculoskeletal healthcare. If you have a sore knee, often the first thing you’ll be referred for is an x-ray; a sore back, perhaps an MRI. In some cases, this is absolutely best practice, and as physios, our job is to understand where this is most appropriate, because there are some huge considerations when referring for imaging, which I’ll explain shortly.
Specifically, when talking about low back pain, we can categorise it as follows: specific or non-specific. (That’s a lot of specificity…)
When we refer to back pain as specific, we are referring to a small collection of conditions that can attribute a certain structure to be causing your pain. These are conditions such as modic changes (vertebral bone marrow degeneration), radiculopathy (nerve root compression), disc herniation and canal stenosis. These conditions make up approximately 8-9% of low back pain cases we will see in clinic.
The non-specific causes make up around 90% of low back pain cases, and when we say non-specific, it means no single identifiable structure in your back can be reliably pinpointed as the root cause.
So why is this important?
This is important because it directly relates to why we refer for imaging.
As a physio, when I’m considering imaging, the first question I ask myself is: “will this image potentially change the course of treatment?” If the answer is yes, it could, then I will refer for a scan. If the answer is no, then I won’t push for an image. However, if you really want to get one, then I don’t have an issue with that. It is important, though, that any imaging you get is talked through with your physio first, because this leads me to the next issue: red herrings.
Our imaging technology is fantastic, but sometimes it’s a little too sensitive. When we take an image of a part of your body, it’s a photo of a point in time, but it doesn’t tell the whole story. A fascinating example of this comes from some large studies looking into the prevalence of disc bulges on MRI compared to the prevalence of back pain in the same population. 30% of completely pain-free 20-year-olds already have a disc bulge, and by age 80, that number climbs to 84%.
So what that tells us is that just because something shows up on a scan doesn’t mean it’s the direct cause of your pain. This is why a clinical assessment is the gold standard in these cases, as 90% of the time, the pain will be non-specific in nature.
There are a few caveats though, and those are red-flag conditions that must be referred for emergency intervention immediately. These are the following symptoms and make up around 1-2% of cases:
- History of cancer – new or worsening back pain in someone with a cancer history
- Unexplained weight loss – alongside back pain, without another clear cause
- Fever or signs of infection – particularly combined with severe or worsening pain
- Significant trauma – a fall, accident, or injury that preceded the pain
- Progressive neurological symptoms – worsening numbness, tingling, or weakness in the legs
- Suspected cauda equina syndrome – loss of bladder or bowel control, numbness in the saddle area (inner thighs, groin, buttocks), or significant leg weakness on both sides. This one is a genuine medical emergency and needs immediate attention, not a wait-and-see approach.
If none of these apply to you, then there’s no genuine rush to get a scan or seek medical attention prior to seeing a physio.
Low back pain is complicated; it’s no wonder we spend so much time studying and learning about it. I would implore everyone with back pain to seek out a relevant healthcare professional to help you navigate the injury, to ensure you’re set on the right path from the start!
And as always, if you need some help, reach out – we’d love to assist you. You can read more about back pain physiotherapy here: Back Pain Physiotherapy
Michael Scardamaglia
Owner, Director & Senior Physiotherapist
