Piriformis test
- Fysiobasen
- Oct 2
- 2 min read
The Piriformis Test is used to evaluate the involvement of the piriformis muscle on the sciatic nerve and to identify piriformis tightness or Piriformis Syndrome.
A positive test may indicate:
Tightness of the piriformis muscle.
Compression of the sciatic nerve → potential cause of Piriformis Syndrome.
Differential diagnosis from lumbar nerve root compression (e.g., disc herniation) [1].
Clinically Relevant Anatomy
Piriformis muscle:
A flat muscle responsible for external rotation, abduction, and extension of the hip.
Origin: Anterior sacrum.
Insertion: Superior aspect of the greater trochanter.
Sciatic nerve (n. ischiadicus):
Most commonly runs under the piriformis.
Can also run through or above the piriformis (less common anatomical variants).
If the piriformis is tight or hypertrophic, it may compress the sciatic nerve, resulting in Piriformis Syndrome.
Test Execution
1. Piriformis Test in Side-Lying (FAIR Test – Flexion, Adduction, Internal Rotation)
Patient position:
Patient lies on the non-affected side.
Test leg flexed to 60–90° at the hip and 90° at the knee.
Patient faces the examiner.
Examiner position:
One hand stabilizes the pelvis.
The other hand pushes the knee down toward the table, inducing horizontal adduction and internal rotation.
Positive test:
Pain in the gluteal region or posterior thigh → suggests piriformis syndrome.
Radiating pain down the leg/foot → suggests sciatic nerve irritation.
2. Seated Piriformis Test
Patient position:
Patient sits upright on a chair with feet flat on the floor.
The affected leg is crossed over the opposite knee (figure-4 position).
Examiner position:
One hand stabilizes the ankle.
The other hand applies lateral pressure to the knee while the patient leans forward.
Positive test:
Pain in the gluteal region → piriformis tightness.
Radiating pain along the sciatic nerve → piriformis compression of the sciatic nerve.
Interpretation
Piriformis Syndrome:
Positive FAIR and seated piriformis tests.
Negative Straight Leg Raise (SLR), distinguishing it from lumbar radiculopathy.
Disc herniation (nerve root compression):
Positive SLR test.
Pain may follow the entire sciatic nerve distribution [3].
Diagnostic Value
High specificity, low sensitivity – may miss some cases of Piriformis Syndrome.
Best used in combination with:
Straight Leg Raise (SLR)
Freiberg’s sign
Palpation of the piriformis muscle [3]
Clinical Relevance
The Piriformis Test is a quick screening tool for piriformis tightness and sciatic nerve irritation. It helps differentiate between piriformis-related pain and lumbar radiculopathy.
Treatment strategies for a positive test include:
Piriformis stretching.
Myofascial release.
Sciatic nerve mobilization techniques.
Conclusion
The Piriformis Test is a simple and practical clinical tool to identify Piriformis Syndrome and differentiate it from lumbar root compression. It should always be interpreted in combination with other clinical tests and findings.
Sources:
Jschuber. Piriformis Test. Available from:https://www.youtube.com/watch?v=PWAKDUPgo_0 [last accessed 7/2/2021]
ATFOCUSPT. Piriformis Stretch. Available from:https://www.youtube.com/watch?v=DE-GGsRtb6k
David J. Magee. Orthopedic Physical Assessment. 6th edition. Missouri: Elsevier Inc., 2014.
Martin HD, Kivlan BR, Palmer IJ, Martin RL. Diagnostic accuracy of clinical tests for sciatic nerve entrapment in the gluteal region. Knee Surgery, Sports Traumatology, Arthroscopy. 2014 Apr;22(4):882-8.
