If your lower back pain keeps flaring up and nobody has been able to explain why, this post is for you.
At The MSK Studio in Adelaide, one of the most common things we hear from new patients is: “It just keeps coming back. I don’t even know what I did.“
The good news is that recurring lower back pain is rarely random. There’s almost always a pattern underneath it. And once that pattern is understood, the path forward becomes a lot clearer.
Below is the framework we use in clinic every time someone comes in with recurring low back pain. It’s called ‘load and capacity‘, and it changes the way most people think about their back.
Dealing with recurring low back pain in Adelaide? Our spinal physiotherapy service is built around exactly this kind of assessment. Book an initial session.
For a full sequence of gentle exercises to work through during a flare-up, see this post.
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What Is Load and Capacity?
The spine has a capacity. Think of it like a bucket.
That bucket represents how much load the spine can comfortably handle at any given point in time. Load is everything the spine is asked to do – lifting, sitting, walking, bending. Even stress and poor sleep contribute to the overall load on the spine.
This is one of the core principles behind how we approach spinal physiotherapy at The MSK Studio – understanding what’s driving the load, not just treating the symptom. It’s also why a thorough initial physiotherapy assessment looks well beyond the moment of injury.
As long as the load stays within the bucket, things feel fine. But the moment load tips over the edge of that bucket, that’s when a flare-up occurs.
Here’s the part most people miss: that bucket isn’t a fixed size. It changes.
After a poor night’s sleep, a stressful week, or a period of reduced movement, the bucket’s capacity can shrink. So the load doesn’t have to increase for a flare-up to happen. Capacity can simply decrease until the gap closes.
That’s why flare-ups often happen during ordinary movements – bending over to put on your shoes, getting out of a chair, reaching for something on a shelf. It’s not that the movement is dangerous. It’s that the capacity was already reduced, and that small movement was enough to tip the bucket over.
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Why This Changes the Right Question to Ask
Think about the last time your lower back flared up. Was there an unusual movement or did it just happen?
Most people say it just happened.
And then they spend days or weeks trying to figure out what they did wrong in that moment. But when load and capacity is understood, the question shifts entirely.
Instead of asking ‘what happened in that moment‘, the more useful question becomes: ‘what was already going on in the days before?‘
- Was sleep worse than usual?
- Had you been on your feet more than normal?
- Was it a particularly stressful period at work?
- Had your movement dropped off – less walking, fewer sessions at the gym
- Did you spike your activity suddenly after a quieter stretch?
Because something shifted. And that something is what reduced capacity until the gap closed. Finding the pattern is the starting point for addressing it.
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What Reduces Spinal Capacity?
Capacity changes. But what actually drives it down? There are a few key factors worth understanding.
1. Sleep
This is the one most people underestimate. Poor sleep can influence how the nervous system responds to load. A run of bad nights can affect what the spine is able to handle in the days that follow — even if nothing else changes.
2. Prolonged Static Positions
Sitting for hours on end fatigues the muscles that support the spine. Think about holding your arm straight out in front of you — after a few minutes the shoulder fatigues. Not because something is wrong, just because it’s been holding one position for too long.
Spinal muscles work in a similar way. After a full day at a desk, they’ve been working for hours with minimal relief. That accumulated fatigue reduces capacity.
3. Stress
This one tends to surprise people. Psychological stress can play a meaningful role in how the body responds to load. A high-stress period may reduce capacity just as significantly as a physical factor – through the nervous system’s effect on pain sensitivity and tissue tolerance.
4. Reduced Movement
When movement decreases, the spine gets less of the nutrient exchange it relies on to stay healthy. The discs in the spine don’t have their own blood supply – they rely on movement to draw in nutrients from surrounding structures. Less movement means reduced nutrient exchange, and over time, reduced capacity. This is a key reason why conditions like sciatica and disc injuries tend to worsen with prolonged inactivity.
All of these factors together – sleep, static load, stress, reduced movement, can quietly shrink the bucket without any obvious warning, until something small tips it over.
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What Builds Spinal Capacity?
Here’s the part that often doesn’t get communicated clearly: capacity isn’t fixed. It can be built over time.
The goal isn’t just to reduce load on the spine. It’s to increase the size of the bucket so the gap between load and capacity stays wide enough that everyday life doesn’t keep closing it.
Two things build capacity most effectively.
1. Spinal Mobility
Most people who exercise regularly are training *around* the spine, not training it directly. Sessions and stretches tend to focus on the arms and legs. But a spine that isn’t moving well is a spine with reduced capacity.
Stiff segments don’t just sit there, they force other parts of the spine to compensate. And that’s where load tends to accumulate.
Incorporating dedicated spinal mobility work, daily, targeted movement specifically through the spine, is one of the more effective ways to start building capacity. Not a general yoga class or a full-body stretch. Deliberate, consistent movement through the spinal segments themselves. This is a core component of clinical pilates for spinal rehabilitation at The MSK Studio.
2. Progressive Strengthening
Once mobility is established, strength is built on top of it. Not isolated exercises in a single plane – full body, functional movement that progressively loads the spine in a controlled and graduated way.
At The MSK Studio, this is where clinical exercise and rehabilitation comes in – progressive, supervised loading that builds the kind of capacity that means a long drive, a stressful week, or a heavy session at the gym is less likely to tip the bucket.
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A Real Example From the Clinic
A client came in recently, mid 50s, going to the gym five days a week, daily walks, stretching every single day. By every measure, they were doing everything right. So why did the lower back keep flaring up every year for the past five years?
A long drive. Bending over to put on shoes. Getting out of a chair.
On assessment, the spine was stiff – not from lack of effort, but because every session and every stretch had been focused on the arms and legs. The spine itself wasn’t getting the attention it needed. This is exactly the kind of presentation our physiotherapist Fardis focusses on identifying.
Despite all the activity, their capacity had a ceiling. And anything that pushed past it, even something small, resulted in a flare-up.
The starting point was daily spinal mobility work. Targeted movement specifically through the spine. Once mobility improved, progressive strength-based rehabilitation was layered in on top of it.
Mobility first. Strength on top of it. That’s the sequence that tends to support capacity building over time.
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What to Do During a Flare-Up
Not sure what’s driving your flare-ups? A spinal physiotherapy assessment at The MSK Studio identifies the pattern and maps out a clear plan. Available in Clovelly Park and Prospect.
When a flare-up actually happens, a few things tend to help.
First – a flare-up is a signal, not a setback. It’s the spine indicating the gap closed. That’s useful information, not a reason to panic.
Second – look at what changed in the days before. Sleep, stress, movement, time on your feet. Finding the pattern tends to reveal the starting point.
Third – keep moving. Reducing load temporarily makes sense, taking a few days away from heavy training gives things a chance to settle. But stopping movement altogether tends to slow recovery rather than help it. Some gentle spinal mobility work, a short walk, low-load movement that keeps things ticking over, that’s generally how capacity comes out the other side of a flare-up. If your flare-up is related to a workplace injury or WorkCover claim, our general physiotherapy service can help navigate that process too.
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To Bring It All Together
Back pain flare-ups aren’t random. There’s usually a pattern underneath.
Load exceeded capacity. And the approach that tends to help long term isn’t avoiding load forever – it’s building a spine whose capacity is wide enough that everyday life doesn’t keep closing the gap.
If you found this helpful and you’re based in Adelaide, you can book an initial spinal physiotherapy session at The MSK Studio. The session covers a full history, an assessment of what’s actually driving your low back pain, and a clear plan for what to do about it.
