title: Reliability and validity of lumbar and abdominal trunk muscle endurance tests in office workers with nonspecific subacute low back pain.
abstract: OBJECTIVE
  Despite the widespread use of trunk endurance tests, the reliability and validity of these tests in office workers with subacute nonspecific low back pain are unknown.
  
  
  METHODS
  This cross-sectional study involved 190 subjects: 30 men and 42 women without low back pain and 47 men and 71 women with low back pain. All subjects underwent timed prone and supine isometric lumbar and abdominal trunk endurance tests that were performed until subjective fatigue occurred. All subjects also completed the Roland Morris and Oswestry self-reported disability questionnaires. A test-retest study (7 days) was conducted with 31 participants with low back pain from the study.
  
  
  RESULTS
  For the abdominal trunk endurance test, males and females with low back pain had mean (SD) values of 62.06 (36.87) and 46.06 (29.28) seconds, respectively, both significantly lower than the asymptomatic workers. For the lumbar test, males and females with low back pain had mean (SD) values of 79.57 (30.66) and 75.49 (28.97) seconds, respectively, again, both significantly lower than the asymptomatic workers. The intraclass correlation coefficients of both tests exceeded 0.90 and the Kappa indices were excellent for both men and women. Receiver-operating curve analyses revealed areas under the curve very close to or exceeding 0.70 for both men and women for both tests.
  
  
  CONCLUSIONS
  The lumbar and abdominal trunk muscle endurance tests appeared to be reliable and valid measures in office workers with subacute low back pain.
authors.affiliation: Department of Sport and Exercise Science, Faculty of Science, The University of Auckland, Auckland, New Zealand Faculty of Sport and Exercise Science, University of Extremadura, Caceres, Spain.
authors.forename: Borja
authors.initials: B
authors.lastname: del Pozo-Cruz
authors.affiliation: Faculty of Sport and Exercise Science, University of Extremadura, Caceres, Spain.
authors.forename: Miguel H
authors.initials: MH
authors.lastname: Mocholi
authors.affiliation: Department of Physical Education and Sport, Faculty of Education, University of Seville, Seville, Spain.
authors.forename: Jesus
authors.initials: J
authors.lastname: del Pozo-Cruz
authors.affiliation: Faculty of Sport and Exercise Science, University of Extremadura, Caceres, Spain.
authors.forename: Jose A
authors.initials: JA
authors.lastname: Parraca
authors.affiliation: Faculty of Sport and Exercise Science, University of Extremadura, Caceres, Spain.
authors.forename: Jose C
authors.initials: JC
authors.lastname: Adsuar
authors.affiliation: Faculty of Sport and Exercise Science, University of Extremadura, Caceres, Spain.
authors.forename: Narcis
authors.initials: N
authors.lastname: Gusi
mesh_terms: D000009:Abdominal Muscles / Q000503:physiopathology*; D000328:Adult; D064131:Back Muscles / Q000503:physiopathology*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D015444:Exercise; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000503:physiopathology*; D008161:Lumbosacral Region; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000503:physiopathology*; D010807:Physical Endurance / Q000502:physiology*; D012372:ROC Curve; D015203:Reproducibility of Results; D057566:Self Report; D011795:Surveys and Questionnaires
keywords: Backache; lower back pain; monitoring; occupational assessment