You know the feeling. The sharp, burning, electric pain that starts somewhere in the lower back or buttock and travels down the leg. Sometimes into the calf. Sometimes all the way to the foot. Sometimes accompanied by numbness or tingling that makes you wonder whether something serious is happening.
You've probably been told it's a disc. Maybe you've had a scan that confirmed some degree of disc bulge or herniation at L4-L5 or L5-S1. You've been given stretches, anti-inflammatories, and a referral to physio. Maybe it settled. Maybe it keeps coming back. Maybe it never fully went away.
Here's what the standard explanation misses — and why so many people with sciatica stay in the cycle longer than they need to.
What sciatica actually is
Sciatica is not a diagnosis. It's a description of a symptom — pain that follows the path of the sciatic nerve down the leg. The nerve itself is being irritated or compressed somewhere along its path, and that irritation is producing the characteristic referred pain.
Where most people get stuck is assuming the compression is always at the disc. A disc bulge pressing on a nerve root is one cause of sciatic pain. It is not the only one, and it is frequently not the primary driver — even when a disc finding shows up on imaging.
The piriformis problem nobody talks about
The sciatic nerve in most people passes directly beneath the piriformis muscle — a deep hip rotator that sits behind the hip joint. In some people it passes through the muscle itself.
When the piriformis is in chronic spasm or becomes hypertonic — which happens as a downstream consequence of dysfunctional movement patterns — it compresses the sciatic nerve and produces symptoms that are clinically indistinguishable from disc-generated sciatica. Same pain distribution. Same referral pattern down the leg. Completely different cause.
This matters enormously because the treatment for piriformis-driven sciatic pain is not spinal. It's hip. And if you've been doing lumbar traction, lumbar stabilisation exercises, and lumbar mobilisation for a problem that's actually originating at the piriformis, you've been working on the wrong part of the system.
Why the disc finding can be misleading
Disc bulges and herniations are genuinely common findings on MRI — and a significant proportion of people who have them experience no symptoms at all. The presence of a disc finding on a scan does not automatically mean the disc is the source of the sciatic pain.
What it means is that the disc has been under load. Discs bulge when they are compressed and loaded in directions they aren't designed to handle — which is exactly what happens when movement patterns are placing chronic load on the lumbar spine. The disc finding is often a downstream consequence of the same movement dysfunction that's driving the piriformis compression and the nerve irritation.
Treating the disc without addressing the movement pattern that loaded it to the point of bulging is, again, treating the output.
What's actually driving both
Whether the compression is at the disc, the piriformis, or both — the upstream cause is almost always a movement pattern problem.
Restricted hip extension in gait
When the hip can't extend properly during walking, the gluteal muscles don't fire effectively through the push-off phase. The piriformis compensates. It takes on load it wasn't designed to carry, goes into chronic tension, and compresses the sciatic nerve. This happens across thousands of steps every day.
Anterior pelvic tilt
A forward-tilted pelvis increases the lumbar curve and changes how the disc is loaded. It also alters the position of the piriformis relative to the sciatic nerve. Both effects increase sciatic nerve irritation risk.
Sitting mechanics
Prolonged sitting in a posteriorly tilted position loads the lumbar discs in exactly the direction most likely to produce posterior bulging. If you sit for hours a day in a slumped position, the disc is being chronically loaded toward the nerve. This is not a disc problem. It's a load management problem.
Old injuries not fully resolved
An ankle sprain, a knee injury, even a shoulder issue can alter gait in ways that change how the hip loads and rotates. The piriformis sits at the end of that chain. Unresolved mechanical issues anywhere below the hip have a direct influence on what happens at the piriformis and the sciatic nerve.
Why sciatica keeps coming back
Sciatica that resolves with rest and returns with activity is almost always a pattern problem. The rest reduces the load on the irritated nerve below the threshold of symptoms. The return to movement reloads the same pattern, compresses the same nerve, and produces the same pain.
The disc didn't re-bulge because you went for a walk. The piriformis returned to its chronic tension state because the movement pattern driving it was never addressed. The cycle continues until the pattern changes.
What surgery does and doesn't fix
Discectomy — surgical removal of the portion of disc pressing on the nerve — can produce genuine relief when the compression is significant and conservative management has failed. But surgery removes the compressed disc material. It does not change the movement pattern that loaded the disc to the point of herniation.
This is why post-surgical sciatica recurrence rates are not negligible. The same pattern, applied to adjacent disc levels or the same level over time, can produce the same problem again. Surgery addresses the acute structural situation. It cannot address what created it.
What actually resolves it
Long-term resolution of sciatica — regardless of whether the source is discal or piriformis — requires identifying and changing the movement pattern that's driving the nerve compression.
That means a full gait assessment to identify where hip extension is breaking down. It means looking at how the pelvis is positioned and moving under load. It means tracing the mechanical chain back to wherever the dysfunction started — which is frequently not in the lower back at all.
From there, the corrective work is progressive and pattern-based. Restoring hip extension in actual movement. Retraining gait mechanics. Removing the load from the structures that have been compensating. Giving the nerve enough mechanical space to stop being irritated.
This takes longer than a cortisone injection. It also addresses what the injection doesn't touch.
What this looks like at Functional Patterns Brisbane
At FP Brisbane, sciatica assessment starts with movement — not the scan. We look at what the hip is doing in gait, where the load is accumulating, and what pattern is driving the nerve compression. From there we build a corrective framework that addresses the source, not just the symptom.
If your sciatica keeps returning, or if you've been told surgery is the next step, it's worth finding out whether the movement pattern has been properly assessed first.