Piriformis syndrome is pain in the buttock and leg caused by the piriformis, a small muscle tucked under the glutes, pressing on or irritating the sciatic nerve. The piriformis runs from the base of the spine to the top of the thigh bone and helps turn the leg outward. The nerve leaves the pelvis right beside the muscle, usually just below it, and in some people passes straight through, so a tight or irritated piriformis is close enough to disturb it. What that tends to produce is a deep ache in one buttock, sometimes with tingling or numbness running down the back of the leg.
A disc and the piriformis can irritate the same nerve, so the pain feels alike
The sciatic nerve begins as several nerve roots leaving the lower spine, which join inside the pelvis before running down the leg. A herniated or bulging disc can press on one of those roots close to the spine. When the piriformis is involved, it presses on the nerve itself, further down. Irritation at either point is felt along the nerve below it, so both can put the same ache in the buttock and the same pins and needles in the calf or foot. A sore spot deep in the buttock feels like a clue, but on its own it settles very little.
Sitting presses on the muscle and nerve, so hours in a seat tend to aggravate it
A long drive or an afternoon at a laptop keeps your weight on the buttock with the hip bent the whole time, and the ache often catches as you finally stand up. A scooter ride adds a firm seat and a position you cannot change until you arrive, with every pothole landing through the same spot. A wallet or phone left in a back pocket puts a hard lump under one side of the pelvis, which makes it the easiest thing here to change. Sitting loads the discs of the lower back as well, though, so a bad day in the chair does not point to the muscle by itself.
No single test confirms it, so a doctor diagnoses it by ruling out the spine
A doctor examines the lower back and hip and tests how the nerves in the leg are working. If the doctor decides imaging is needed, it is used to look for a disc pressing on a nerve root, or for spinal stenosis, a narrowing of the space the nerves travel through. The hip joint and the joint where the spine meets the pelvis can send pain into the buttock as well, so they belong in the same check. When moving or pressing on the piriformis brings on the familiar pain and nothing else accounts for it, the name starts to fit.
Getting that order wrong is an easy mistake. It can mean weeks of attention on a buttock muscle while a disc that needed a doctor goes unexamined.
The Sync measures and supports movement alongside medical care, not in place of it
A visit starts with objective assessment, with the readings shown on screen as they are taken, so you can see how the lower back and hips are moving. Computer-guided spinal mobilisation through SpinalSync and soft tissue work through MyoSync, two of the platforms in The Sync System, then support comfort and movement, and repeat measurement tracks any change between visits. If the assessment turns up something a doctor should see, a Sync specialist says so early. The wider picture of nerve pain down the leg is on our sciatica page, and the other presentations we see sit on our conditions page.
Common questions about piriformis syndrome
Not quite. Sciatica describes pain along the sciatic nerve, whatever is irritating it, and piriformis syndrome is one possible cause. A disc or a narrowing in the lower back can produce the same pattern.
It usually affects one side. Pain, tingling or numbness in both legs at once points toward the spine and needs urgent medical attention.
Have the pain examined first, because a buttock stretch is aimed at the muscle and the source may be higher up. If any stretch sends tingling or numbness further down the leg, stop and get it checked.
No. Naming the cause is a doctor's call, and we do not diagnose, prescribe medication, inject, operate, or provide or read imaging. We assess and measure how the hip and lower back move, monitor change, and support comfort and movement.
Written by the Aphyx Content team, reviewed by the clinical team at The Sync. Published 9 October 2026. Last updated 9 October 2026.