Lower Back Pain: A Clinician's Guide to What's Actually Going On

Back pain is the most common musculoskeletal complaint in Australia, and one of the most common reasons anyone sees any health practitioner. It is also the area where the gap between what patients are told and what the evidence supports is widest.

So let us start with the part that surprises people most.

Most back pain has no identifiable structure to blame

Somewhere around eighty to ninety per cent of low back pain is classified as “non-specific”. That does not mean nobody knows what is wrong. It means the pain cannot be reliably attributed to one specific structure, because the joints, discs, muscles and ligaments of the lower back all refer pain to overlapping areas and no test distinguishes between them cleanly.

This is genuinely good news, and it usually does not land that way. “Non-specific” sounds dismissive. What it actually means is that the serious causes have been ruled out and the problem is mechanical — which is the category that responds best to movement, load management and time.

The remaining ten to twenty per cent divides into identifiable causes: radicular pain from nerve root irritation, spinal stenosis, fractures, and a small number of specific pathologies. Distinguishing these is what an assessment is for.

What actually contributes

Very few back pain episodes have a single cause. Usually several things line up:

A change in load. A house move, a new gym programme, a long drive, a weekend of gardening after months of sitting. The most common story is not too much load in absolute terms but too much change in load too quickly.

Sustained positions. Sitting for hours flattens the lumbar curve and shifts load forward onto the discs. Not harmful briefly. Cumulative over years.

Sleep and stress. Both genuinely affect pain sensitivity, and both are usually worse in the period before a back pain episode. This is a physiological effect, not a suggestion that the pain is imagined.

Deconditioning. Tissue that is loaded regularly tolerates load better. Tissue that is not, does not.

A specific incident. Sometimes there is one. Often the incident is trivial — bending to pick up a sock — which tells you the sock was not the cause. It was the last straw on a back that was already at its limit.

Why scans are usually unhelpful

This is worth spending a moment on, because it changes how people feel about their own backs.

If you scanned a large group of adults with no back pain at all, a substantial proportion would show disc degeneration, disc bulges and other “abnormal” findings — and the proportion rises steadily with age. These findings are, for the most part, normal age-related change. Grey hair for your spine.

The consequence is that a scan of a painful back will usually find something, and there is often no way to know whether that something is causing the pain or was there for a decade beforehand. Being told you have degeneration and a bulging disc, when both may be incidental, reliably makes people more fearful and less active — and both of those make outcomes worse.

Imaging earns its place when there are red flags, significant trauma, or neurological signs, or when surgery is being considered. Otherwise it tends to add anxiety rather than information.

What treatment does

For mechanical low back pain, the components that have support behind them:

Stay active. The strongest recommendation in every modern guideline. Prolonged rest worsens outcomes. Movement within tolerance, continued as far as possible, produces better results than rest.

Manual therapy. Joint mobilisation, adjustment and soft tissue work can reduce pain and improve movement in the short term. That short-term window is genuinely useful — it is what lets someone get back to moving normally, which is the thing that actually drives recovery.

Graded exercise. Progressive loading, built up over weeks. The specific exercise type matters less than doing something progressive and sticking with it.

Education and reassurance. Underrated and effective. Understanding that your back is not damaged, that hurting is not harming, and that the pain will most likely settle changes behaviour, and behaviour changes outcome.

Honest expectations: most acute episodes improve substantially within two to six weeks. Recurrence is common — most people who have one episode will have another — and that is a normal feature of back pain rather than a treatment failure.

What to do about it

If your back pain started recently, is mechanical in character, and has no red flags: keep moving, avoid bed rest, and give it a couple of weeks. A large proportion resolves on its own.

If it has not improved in two to three weeks, keeps recurring, or is limiting what you can do, an assessment is worth having — mostly to establish what is driving it in your case and what loading changes will keep it away.

We treat back pain daily at Marrickville and Wetherill Park, and for the majority of people the plan is a short course of hands-on treatment while we build the exercise and load management that does the durable work.