title: A literature review of clinical tests for lumbar instability in low back pain: validity and applicability in clinical practice.
abstract: BACKGROUND
  Several clinical tests have been proposed on low back pain (LBP), but their usefulness in detecting lumbar instability is not yet clear. 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.
  
  
  METHODS
  We searched studies of the accuracy and/or reliability of Prone Instability Test (PIT), Passive Lumbar Extension Test (PLE), Aberrant Movements Pattern (AMP), Posterior Shear Test (PST), Active Straight Leg Raise Test (ASLR) and Prone and Supine Bridge Tests (PB and SB) in Medline, Embase, Cinahl, PubMed, and Scopus databases. Only the studies in which each test was investigated by at least one study concerning both the accuracy and the reliability were considered eligible. The quality of the studies was evaluated by QUADAS and QAREL scales.
  
  
  RESULTS
  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 showed 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), whereas the inter-rater reliability of the PST was fair (k = 0.27).
  
  
  CONCLUSIONS
  The data from the studies provided information on the methods used and suggest that PLE is the most appropriate tests to detect lumbar instability in specific LBP. However, due to the lack of available papers on other lumbar conditions, these findings should be confirmed with studies on non-specific LBP patients.
authors: Master of Manual Therapy and Musculoskeletal Rehabilitation, Department of Molecular Medicine, University of Padova, Padova, Italy.
authors: Silvano
authors: S
authors: Ferrari
authors: Physical Therapy Private Practice, Treviso, Italy.
authors: Tiziana
authors: T
authors: Manni
authors: Physioup Physical Therapy Private Practice, Rome, Italy.
authors: Francesca
authors: F
authors: Bonetti
authors: IRCCS Don Gnocchi Foundation, Milan, Italy.
authors: Jorge Hugo
authors: JH
authors: Villafañe
authors: Master of Manual Therapy and Musculoskeletal Rehabilitation, Department of Molecular Medicine, University of Padova, Padova, Italy.
authors: Carla
authors: C
authors: Vanti
keywords: Aberrant movements pattern; Joint instability; Low back pain; Lumbar instability; Passive lumbar extension test; Physical examination; Posterior shear test; Prone instability test; Reproducibility of results