Execution
- 1Position the patient prone with the hips neutral and the patient relaxed.
- 2Passively flex the patient’s knee as far as possible toward the buttock while preventing hip rotation.
- 3Hold the flexed-knee position for approximately 45 to 60 seconds when needed to reproduce neural symptoms.
- 4Modify the test by passively extending the hip if knee pathology prevents flexion beyond 90°.
- 5Differentiate anterior thigh stretch from lumbar, buttock, posterior thigh, or femoral-nerve symptoms.
Positive outcome
Unilateral neurological pain in the lumbar area, buttock, posterior thigh, or anterior thigh is positive. Anterior thigh pain may indicate femoral nerve mechanosensitivity or quadriceps tightness, so symptom quality and history must be used to differentiate. Magee links the basic prone knee bending position to femoral nerve and L2-L4 nerve-root stress.
Studies
| Study | Reliability | Sn | Sp | LR+ | LR− |
|---|---|---|---|---|---|
| Suri et al. (2011) | NA | 50 | 100 | infinity | 0.50 |
CommentSuri’s femoral stretch data support useful rule-in value for midlumbar nerve-root impingement, but the 100% specificity creates an infinite LR+ from a limited sample and should not be treated as a stable multiplier. Magee cautions that rectus femoris tightness and anterior pelvic torsion can produce anterior thigh or lumbar pain during this test. Use the test primarily when L2-L4 or femoral nerve involvement is clinically plausible.
High Clinical Value