Pain, disability, and diagnostic accuracy of clinical instability and endurance tests in subjects with lumbar spondylolisthesis

Objective: The aims of this study were (1) to investigate the relationship between the main clinical tests to detect spinal instability, the perceived pain and disability, and symptomatic spondylolisthesis (SPL) characteristics, (2) to investigate the relationship between endurance and instability tests, and (3) to measure the diagnostic sccuracy of these tests in unstable SPL diagnosed against dynamic radiographs. Methods: Four instability tests were evaluated on 119 subjects: aberrant movements, active straight leg raising (ASLR), prone instability test, and passive lumbar extension test (PLE); and 2 endurance tests, prone bridge test and supine bridge test (SBT). The results were compared with the numeric rating scale for pain and the Oswestry Disability Index for disability. These tests were used as index tests and compared with dynamic radiographs as reference standard on 64 subjects. Results: A significant relationship between disability and all the clinical tests but ASLR was observed. The relation between tests and pain was weaker, not significant for prone instability test and aberrant movement and critical for ASLR (P = .05). There was a low relationship between endurance tests and instability tests. Only PLE showed a significant association with dynamic radiographs (P = .017). Conclusion: Endurance and instability tests appear to be weakly related to the amount of pain but significantly related to the disability in symptomatic SPL. Of the tests evaluated, PLE exhibited the best ability to predict positive dynamic radiographs.