Where the Sciatic Nerve Gets Trapped: Piriformis Syndrome and Deep Gluteal Syndrome

Not all sciatica comes from the spine. Once the sciatic nerve leaves the lower back and enters the buttock, it passes through a tight space surrounded by muscles, tendons, and bony structures. If any of these structures compress or irritate the nerve along this path, you can get the same burning, shooting, tingling symptoms down your leg, but the source has nothing to do with a disc or the spine itself.

This is an important distinction, because the treatment for nerve entrapment in the buttock is different from treatment for a lumbar disc problem. Getting the diagnosis right is the first step toward getting better.

The Deep Gluteal Space: A Tight Neighbourhood

After the sciatic nerve exits the pelvis, it passes through what’s called the deep gluteal space. Think of it as a narrow corridor in your buttock, bordered by bone, muscle, and connective tissue. The nerve has to thread through this space without being compressed, and there’s not a lot of room for error.

The structures in and around this space include the piriformis muscle, the gemelli muscles (superior and inferior), the obturator internus, the quadratus femoris, and the hamstring tendons at their attachment point on the ischial tuberosity (your “sit bone”). Any of these structures can potentially compress or irritate the sciatic nerve.

Piriformis Syndrome

The piriformis is the structure most people have heard of when it comes to sciatic nerve entrapment, and it’s the most commonly discussed cause of non-spinal sciatica.

What Is the Piriformis?

The piriformis is a small, flat muscle that sits deep in your buttock, running from the front of the sacrum to the top of the femur (thigh bone). Its main job is to externally rotate and stabilize the hip. The sciatic nerve typically passes directly underneath the piriformis muscle as it exits the pelvis.

In approximately 10 to 20% of people, the sciatic nerve has an anatomical variation where part of the nerve actually passes through the piriformis muscle rather than underneath it. This variation may increase susceptibility to compression.

How It Causes Symptoms

Piriformis syndrome occurs when the piriformis muscle compresses or irritates the sciatic nerve. This can happen because the muscle is tight, inflamed, or in spasm. Common triggers include prolonged sitting (especially on hard surfaces), overuse from activities like running or cycling, direct trauma to the buttock, or hip dysfunction that causes the piriformis to work harder than it should.

The symptoms often include deep buttock pain that worsens with sitting, pain that travels down the back of the leg following the sciatic nerve distribution, and discomfort that gets worse with activities like climbing stairs, squatting, or crossing your legs. Unlike spinal sciatica, piriformis syndrome typically doesn’t cause significant low back pain, and coughing or sneezing usually doesn’t make the leg pain worse.

How Common Is It?

Piriformis syndrome is estimated to account for 5 to 8% of low back and buttock pain cases. It’s more common in women than men, and it’s frequently seen in people who sit for extended periods or participate in activities that heavily load the hip rotators.

Deep Gluteal Syndrome: The Bigger Picture

For years, the term “piriformis syndrome” was used as a catch-all for sciatic nerve entrapment in the buttock. But we now know that several other structures in the deep gluteal space can also compress the nerve. The broader term “deep gluteal syndrome” (DGS) has emerged to describe any non-spinal, non-discogenic cause of sciatic nerve entrapment in the gluteal region.

An estimated 6 to 17% of patients with sciatica in secondary care meet the diagnostic criteria for deep gluteal syndrome.

Other Entrapment Points

Gemelli-obturator internus complex. The sciatic nerve passes close to these small rotator muscles below the piriformis. Inflammation, scarring, or fibrotic bands in this area can tether or compress the nerve.

Hamstring origin. The hamstring tendons attach to the ischial tuberosity (your sit bone), and the sciatic nerve runs very close to this attachment point. Hamstring tendinopathy, scar tissue from a previous tear, or bony irregularities at the sit bone can compress the nerve. This is particularly common in runners and people who do a lot of sprinting or kicking.

Fibrous bands and vascular structures. Fibrous bands of connective tissue can form in the deep gluteal space, especially after trauma or surgery. These bands can tether the sciatic nerve and restrict its normal gliding motion. Blood vessels in the region can also occasionally compress the nerve.

Ischiofemoral impingement. This occurs when the space between the ischium (part of the pelvis) and the femur narrows, compressing the structures that pass through it, including the sciatic nerve. It’s associated with hip dysfunction and altered gait patterns.

How to Tell the Difference: Spinal vs. Non-Spinal Sciatica

This is one of the most important parts of your assessment, because the treatment approach depends on where the nerve is being irritated.

Clues That Suggest a Spinal Cause

  • Low back pain accompanies the leg symptoms
  • Coughing, sneezing, or bearing down increases leg pain
  • Bending forward or sitting increases symptoms
  • Specific dermatomal patterns (symptoms follow a predictable nerve root distribution)
  • Changes in reflexes at the knee or ankle

Clues That Suggest an Entrapment in the Buttock

  • Deep buttock pain is the primary complaint
  • Prolonged sitting on hard surfaces is a major aggravator
  • Pain with hip rotation, especially internal rotation
  • No significant low back pain
  • Tenderness when pressing over the deep gluteal area
  • Symptoms are provoked by hip-specific tests rather than spinal movements

A combination of clinical tests helps distinguish between these causes. Tests like the seated piriformis test, the active piriformis test, and the FAIR test (Flexion, Adduction, Internal Rotation) are used to assess for sciatic nerve compression in the deep gluteal space. A 2024 cross-sectional study found that the combination of the seated and active piriformis tests had a sensitivity of 91% and specificity of 80% for detecting deep gluteal syndrome.

How We Treat Sciatic Nerve Entrapment

At Fredericton Family Chiropractic, treatment for non-spinal sciatic nerve entrapment focuses on reducing compression, restoring normal nerve mobility, and addressing the underlying cause.

Chiropractic Care

Joint dysfunction in the hip, sacroiliac joint, and lumbar spine can all contribute to altered muscle activation patterns that increase compression on the sciatic nerve. Restoring normal joint mechanics through mobilization and adjustments helps reduce the load on the deep gluteal structures.

Soft Tissue Therapy

Targeted soft tissue work on the piriformis, glutes, and hip rotators helps reduce muscle tension and spasm that may be compressing the nerve. This is often one of the most immediately helpful interventions for patients with piriformis syndrome.

Functional Rehabilitation

Rehabilitation exercises address the underlying dysfunction that led to the entrapment in the first place. This may include hip strengthening (particularly the gluteus medius and external rotators), hip mobility work, neural mobilization techniques to restore normal sciatic nerve gliding, and core stabilization to reduce compensatory patterns. Stretching of the piriformis and hip rotators is often part of the program, but it’s not the whole picture. If the entrapment is being driven by hip weakness or movement dysfunction, stretching alone won’t resolve it.

A systematic review of conservative treatments for deep gluteal syndrome found that manual therapy combined with targeted exercise produces favorable outcomes for the majority of patients.

Evidence and Sources

  1. Martin HD et al. Deep gluteal syndrome: an overlooked cause of sciatica. Arthroplasty Today. 2019.
  2. Hopayian K, Danielyan A. Piriformis syndrome: a systematic review of case reports. BMC Surgery. 2025.
  3. Martin HD et al. Deep gluteal space problems: piriformis syndrome, ischiofemoral impingement and sciatic nerve release. Muscles, Ligaments and Tendons Journal. 2016.
  4. Carro LP et al. Deep gluteal space problems: piriformis syndrome, ischiofemoral impingement, and sciatic nerve release. EFORT Open Reviews. 2021.
  5. Siddiq MAB. Piriformis syndrome and wallet neuritis: are they the same? Cureus. 2018.
  6. Vassalou EE et al. A systematic review of conservative and surgical treatments for deep gluteal syndrome. Musculoskeletal Science and Practice. 2022.
  7. Defined cross-sectional study. Exploring non-invasive diagnostic tools for deep gluteal syndrome: a multimodal approach integrating clinical and imaging techniques. PMC. 2024.