Piriformis syndrome: when your glute is strangling your sciatic nerve.

You have deep pain in the right buttock. Sometimes it shoots down the back of your thigh. Sitting makes it worse. Getting up from a chair makes it worse. You might even feel a burning ache when you walk for too long. You've been told you have sciatica — and technically, that's not wrong. But if your MRI came back clean and the nerve root blocks haven't done much, there's a good chance the source isn't your disc at all. It's your piriformis.

What the piriformis actually is — and why it matters

The piriformis is a small, deep external rotator muscle buried in the glute. It runs from the sacrum — the triangular bone at the base of your spine — to the top of the femur. Its job is to rotate your hip outward and stabilize the hip joint during weight bearing. Most people have never heard of it until it becomes a problem.

The reason it causes so much trouble is anatomy. The sciatic nerve — the largest nerve in the body, roughly as thick as your thumb — exits the pelvis just below (and in some people, directly through) the piriformis. Research published through NCBI notes that in roughly 17% of the population, the sciatic nerve actually passes through the piriformis muscle belly, making those individuals significantly more vulnerable to compression when the muscle tightens.

When the piriformis spasms, shortens, or develops trigger points, it can squeeze the nerve. The result is pain that runs from the buttock down the back of the leg — pain that feels, to the patient, completely identical to disc-driven sciatica.

Who develops piriformis syndrome

It's not random. Certain movement patterns and lifestyle factors load the piriformis disproportionately:

• Runners and cyclists — repetitive hip flexion without adequate external rotation work shortens the piriformis over time. Add in weak glute medius and you've got a muscle constantly compensating.
• Desk workers who cross their legs — this sustained position loads the piriformis on the crossed side and is one of the most common setups we see.
• Lifters with hip dominance patterns — athletes who squat or deadlift with more hip drive than knee flexion often develop asymmetrical piriformis tension.
• Anyone who had a direct fall onto the glute — trauma can trigger a spasm that never fully resolves.

Why it gets misdiagnosed constantly

Here's the core problem: an MRI of the lumbar spine will often look normal. No disc herniation at L4-L5. No foraminal narrowing. No obvious nerve root compression. So the patient gets handed a diagnosis of "non-specific sciatica" and sent off with anti-inflammatories and a generic referral for physical therapy.

The issue is that standard lumbar imaging doesn't image the piriformis. You'd need a dedicated pelvic MRI or ultrasound with a clinician who's specifically looking for it. And most radiologists aren't hunting for piriformis pathology unless specifically asked.

Piriformis syndrome accounts for roughly 6–8% of all sciatica-like presentations — which sounds small until you consider how many millions of people are walking around with unresolved "sciatica" that hasn't responded to disc-focused treatment.

How we tell the difference in clinic

The clinical exam is where this gets sorted. There are a handful of reliable signs that point toward piriformis rather than disc:

• Positive FAIR test — hip flexion, adduction, and internal rotation reproduces the buttock and leg pain. This puts the piriformis on stretch over the nerve.
• Pain with prolonged sitting — especially on hard surfaces. The piriformis is compressed between the chair and the hip when seated.
• No dermatomal pattern to the numbness — disc-driven sciatica follows predictable nerve root maps (L4 goes here, S1 goes there). Piriformis-driven pain is less predictable.
• Reflexes intact — if your Achilles reflex is normal and your quad reflex is normal, the nerve root itself isn't being damaged. That's a good sign it's compression at the hip, not the spine.
• Point tenderness deep in the glute — pressing directly over the piriformis reproduces the symptoms.

None of these in isolation is definitive, but when several line up, the picture becomes clear.

What treatment looks like at The Spine Studio

Once we've confirmed piriformis as the primary driver, the treatment approach is very different from disc-based sciatica — and that's the point. Treating the wrong source with the wrong tools is why so many patients plateau.

At The Spine Studio, a piriformis syndrome plan typically involves:

• Direct soft-tissue work on the piriformis and deep external rotators — we use manual therapy and instrument-assisted techniques to release the muscle belly and reduce trigger point activity. This is not comfortable the first visit, but most patients feel meaningful relief within two to three sessions.
• Spinal adjustments at L4-S1 — even when the disc isn't the primary cause, the lumbar segments above the piriformis attachment are often restricted. Restoring segmental motion reduces the overall neural load on that region.
• Neural mobilization (nerve flossing) — gentle sciatic nerve gliding through its full excursion reduces sensitivity and improves the nerve's tolerance to compression.
• Hip mobility programming — targeted external rotation stretching, hip 90/90 work, and pigeon variations to create lasting length in the deep rotator group.
• Glute strengthening — a weak glute medius is almost always part of the story. The piriformis overworks because it's picking up the slack. Building the primary movers takes the chronic tension off the piriformis.