The Relationship Between Clinical Instability and Endurance Tests, Pain, and Disability in Nonspecific Low Back Pain.

OBJECTIVE The aims of this study were (1) to investigate the relationship between clinical tests detecting spinal instability and the perceived pain and disability in nonspecific low back pain and (2) to investigate the relationship between endurance and instability tests. METHODS Four instability tests (aberrant movements, active straight leg raising, prone instability test, and passive lumbar extension test) and 2 endurance tests (prone bridge test [PBT] and supine bridge test [SBT]) were performed on 101 participants. Their results were compared with the Numerical Rating Scale and the Oswestry Disability Index evaluating pain and disability, respectively. RESULTS A low to moderate significant relationship between pain, disability, and all tests with the exception of PBT was observed. A low to moderate significant relationship between endurance tests and instability tests was also shown. The results of PBT and SBT were significantly related to the duration of symptoms (P = .0014 and P = .0203, respectively). CONCLUSION The results of endurance and instability tests appear to be related to the amount of pain and the disability in nonspecific low back pain. The persistence of pain significantly reduces anterior and posterior core muscle endurance.