A number of clinical tests have been suggested for low back pain (LBP), but their usefulness in detecting lumbar instability remains unclear. The objective of this literature review was to investigate the clinical validity of the main clinical tests used for the diagnosis of lumbar instability in individuals with LBP and to verify their applicability in everyday clinical practice. Six papers considering 333 LBP patients were included. The PLE was the most accurate and informative clinical test, with high sensitivity (0.84, 95% CI: 0.69 – 0.91) and high specificity (0.90, 95% CI: 0.85 -0.97). The diagnostic accuracy of AMP depends on each singular test. The PIT and the PST demonstrated by fair to moderate sensitivity and specificity [PIT sensitivity = 0.71 (95% CI: 0.51 – 0.83), PIT specificity = 0.57 (95% CI: 039 – 0.78); PST sensitivity = 0.50 (95% CI: 0.41 – 0.76), PST specificity = 0.48 (95% CI: 0.22 – 0.58)]. The PLE displayed a good reliability (k = 0.76), but this result comes from a single study. The inter-rater reliability of the PIT ranged by slight (k = 0.10 and 0.04), to good (k = 0.87). The inter-rater reliability of the AMP ranged by slight (k = -0.07) to moderate (k = 0.64), while the inter-rater reliability of the PST was fair (k = 0.27).
The data from the studies provided information on the methods employed and indicate that PLE is the most appropriate tests to detect lumbar instability in specific LBP. Although, due to the lack of available papers on other lumbar conditions, these findings ought to be confirmed with studies on non-specific LBP patients.