The flip test, also known as the Braggard test or sciatic stretch test, is a physical examination maneuver used to assess for sciatic nerve irritation or compression, often associated with sciatica.
How the Flip Test (Braggard Test) is Performed:
The flip test is a variation of the straight leg raise test, designed to more specifically target the sciatic nerve. Here's how it's typically conducted:
- Patient Positioning: The patient lies supine (on their back) with legs extended.
- Straight Leg Raise: The examiner slowly raises the patient's affected leg, keeping the knee straight. The test is positive if the patient experiences pain radiating down the leg in the distribution of the sciatic nerve.
- Dorsiflexion Enhancement (Braggard's Maneuver): At the point where pain is elicited (or before, if the examiner anticipates a positive test), the examiner lowers the leg slightly (typically a few degrees) to reduce the pain. The examiner then dorsiflexes the patient's foot (bends the foot upwards at the ankle).
- Positive Result: An increase in pain with dorsiflexion of the foot is considered a positive Braggard's test, suggesting sciatic nerve irritation. This is because dorsiflexion further stretches the sciatic nerve.
Interpretation of Results:
- Positive Test: A positive flip test indicates potential sciatic nerve involvement. The pain usually follows the path of the sciatic nerve, which runs from the lower back down the back of the leg.
- Negative Test: A negative test doesn't entirely rule out sciatica, as the test may not always be sensitive enough to detect subtle nerve compressions.
Important Considerations:
- Pain Location: It's important to distinguish between hamstring tightness (which causes pain in the back of the thigh) and true sciatic nerve pain (which radiates down the leg).
- Reproducibility: A reliable test should produce consistent results when repeated.
- Clinical Correlation: The flip test should be interpreted in conjunction with the patient's history, other physical examination findings, and imaging studies (like MRI) if needed.
- Differentiation: This test helps differentiate between nerve root irritation and muscular tightness or pain.
In summary, the flip test helps clinicians evaluate sciatic nerve involvement by assessing pain response to sciatic nerve stretching induced by straight leg raising and enhanced with foot dorsiflexion.
