title: Inter- and intra-observer reliability of clinical movement-control tests for marines.
abstract: BACKGROUND
  Musculoskeletal disorders particularly in the back and lower extremities are common among marines. Here, movement-control tests are considered clinically useful for screening and follow-up evaluation. However, few studies have addressed the reliability of clinical tests, and no such published data exists for marines. The present aim was therefore to determine the inter- and intra-observer reliability of clinically convenient tests emphasizing movement control of the back and hip among marines. A secondary aim was to investigate the sensitivity and specificity of these clinical tests for discriminating musculoskeletal pain disorders in this group of military personnel.
  
  
  METHODS
  This inter- and intra-observer reliability study used a test-retest approach with six standardized clinical tests focusing on movement control for back and hip. Thirty-three marines (age 28.7 yrs, SD 5.9) on active duty volunteered and were recruited. They followed an in-vivo observation test procedure that covered both low- and high-load (threshold) tasks relevant for marines on operational duty. Two independent observers simultaneously rated performance as "correct" or "incorrect" following a standardized assessment protocol. Re-testing followed 7-10 days thereafter. Reliability was analysed using kappa (κ) coefficients, while discriminative power of the best-fitting tests for back- and lower-extremity pain was assessed using a multiple-variable regression model.
  
  
  RESULTS
  Inter-observer reliability for the six tests was moderate to almost perfect with κ-coefficients ranging between 0.56-0.95. Three tests reached almost perfect inter-observer reliability with mean κ-coefficients > 0.81. However, intra-observer reliability was fair-to-moderate with mean κ-coefficients between 0.22-0.58. Three tests achieved moderate intra-observer reliability with κ-coefficients > 0.41. Combinations of one low- and one high-threshold test best discriminated prior back pain, but results were inconsistent for lower-extremity pain.
  
  
  CONCLUSIONS
  Our results suggest that clinical tests of movement control of back and hip are reliable for use in screening protocols using several observers with marines. However, test-retest reproducibility was less accurate, which should be considered in follow-up evaluations. The results also indicate that combinations of low- and high-threshold tests have discriminative validity for prior back pain, but were inconclusive for lower-extremity pain.
authors.affiliation: Department of Neurobiology, Care Sciences and Society, Division of Physiotherapy, Karolinska Institutet, Huddinge, Sweden.
authors.forename: Andreas
authors.initials: A
authors.lastname: Monnier
authors.forename: Joachim
authors.initials: J
authors.lastname: Heuer
authors.forename: Kjell
authors.initials: K
authors.lastname: Norman
authors.forename: Björn O
authors.initials: BO
authors.lastname: Äng
mesh_terms: D000328:Adult; D001416:Back Pain / Q000175:diagnosis / Q000503:physiopathology; D001696:Biomechanical Phenomena; D003937:Diagnosis, Differential; D005260:Female; D006621:Hip Joint / Q000503:physiopathology*; D006801:Humans; D008159:Lumbar Vertebrae / Q000503:physiopathology*; D008297:Male; D008887:Military Medicine / Q000379:methods*; D008889:Military Personnel; D009043:Motor Activity; D009068:Movement; D009140:Musculoskeletal Diseases / Q000175:diagnosis* / Q000503:physiopathology; D015588:Observer Variation; D009784:Occupational Diseases / Q000175:diagnosis* / Q000503:physiopathology; D010147:Pain Measurement; D010808:Physical Examination; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013548:Sweden; D055815:Young Adult