Prone Knee Bending Test / Reverse Lasègue / Femoral Nerve Test | Radicular Pain

Execution:

1. Patient is in prone lying position
2. The examiner passively maximally flexes the knee (some authors recommend to hold this position 45-60s)
3. If unable to flex the knee past 90° or to add further stretch on the femoral nerve, the examiner can extend the hip

 

Positive Outcome: Patient reports shooting pain down the leg upon maximal knee (or added hip) flexion, which is indicative for nerve root compression at L2-L4

Study	Reliability	Sn	Sp	LR+	LR-
Suri et al. (2011) for L2-L4	NA	50	100	∞	0.5
Suri et al. (2011) for L3 only	NA	70	88	5.7	0.34
Comment: This test can be used to make the diagnosis of a higher disc herniation with nerve root compression more likely