Diagnostic Accuracy of the Passive Straight Leg Raise Test in Detecting Compression of the Lower Lumbar Nerve Roots

• Published in: The Internet journal of allied health sciences and practice
• Main Authors: Hussein, Hisham M., Kamel, Ehab M., Ragab, Mohamed M., Elerian, Ahmed I.
• Format: Journal Article
• Language: English
• Published: 22-03-2024
• ISSN: 1540-580X; 1540-580X
• DOI: 10.46743/1540-580X/2024.2425

Background: Lumbar nerve root compression is a pathological condition that occurs commonly in the low back pain population. Passive straight leg raise (SLR) is a clinical test widely used to confirm this pathological condition. Yet, its diagnostic accuracy needs further investigation. Objective: To assess the sensitivity and specificity of the passive SLR test in detecting compression of the lower lumbar nerve roots using magnetic resonance imaging as a reference standard. Design: This study is a prospective diagnostic-accuracy study. Methods: One hundred-and-twelve participants (82 males and 30 females) met the inclusion criteria and joined the study. Participants were recruited through direct communication and poster announcement and allocated into positive and negative MRI groups. A standardized passive SLR test was applied to all participants; then 2 X 2 cross-tabulation statistics were conducted to determine the sensitivity and specificity. Results: The passive SLR test was considered positive in 62 (56.36%) participants while it was negative in 50 (45.45%) participants. Sensitivity, specificity, positive and negative likelihood ratios were found to be 77.1%., 81.0%, 6.75, and 0.47 respectively. The diagnostic accuracy was found to be 80.95%. ROC curve revealed positive fair sensitivity and specificity of the test with the area under the curve equal to 0.775. Conclusion: The passive SLR test is a useful tool for the diagnosis of lower lumbar nerve root compression.