Posterior Sag Sign (Godfrey's Test) Special Test
Orthopedic Physical Examination & Clinical Assessment Guide
What is it used for?
- Visual assessment of PCL integrity.
How to Perform
- Position: Patient lies supine with hips flexed 45° and knees flexed 90°.
- Action: Observe the profile of the tibia from the side.
Interpretation of Results
- Positive Test: The tibia “sags” or drops back visibly compared to the femur (loss of the normal tibial step-off).
Diagnostic Accuracy
- Sensitivity: 79%
- Specificity: 100%
Clinical Context & Limitations
The Posterior Sag Sign (Godfrey's Test) should be considered as one component of a comprehensive musculoskeletal assessment. No single special test has perfect diagnostic accuracy; thus, clinical decision-making should integrate test results with patient-reported symptoms, mechanism of injury, functional impairment, and relevant imaging.
Clinicians should be aware of potential false-positive results in patients with pain sensitisation, muscle guarding, or poor relaxation. For the Knee region, combining the Posterior Sag Sign (Godfrey's Test) with complementary examination tests significantly improves overall diagnostic confidence.
References
- Magee, D. J. (2021). Orthopedic Physical Assessment.
