Piriformis syndrome, Clinic
- Aching pain from the sit bone, possibly radiating down the back of the thigh
- Perceived as a condition with neuropathy (that a nerve is being pinched by or in the muscle)
- Approximately 0.6 percent of sciatica symptoms may be due to piriformis
- Common symptoms
- When sitting with legs crossed, one may experience pain radiating to the back of the thigh
- One may experience pain when sitting with a straight back, as during prolonged car driving
- There is tenderness along the course of the sciatic nerve, approximately midway between the ischial tuberosity and the greater trochanter.
Piriformis syndrome
M. piriformis pain provocation test
- Side-lying, hip flexed at 60°, knee flexed. Stabilize the hip with one hand and press the knee down
- Tight M. piriformis
- Pain in the muscle
- M. piriformis compresses the sciatic nerve
- Radiating pain in the leg
- In 15% of the population, the sciatic nerve passes through M. piriformis, and they have a higher chance of a positive test
Bonnet sign
- The patient lies on their back. Hip and knee flexed
- Press the hip and knee into adduction and internal rotation of the hip
- Ask the patient to rotate the hip outward against resistance
- Positive test if radiating pain in the posterolateral thigh and leg
Bonnet sign, anatomy
- Flexed hip
- Internally rotated hip
- Adducted hip
- The patient rotates the hip outward against resistance