title: Validity and reliability of sincerity test for dynamic trunk motions.
abstract: OBJECTIVE
  Marras et al. developed a technique to evaluate sincerity of effort during dynamic trunk motion performance. The validity and reliability of the technique have not been evaluated. Therefore, the objective of this study was to first determine whether or not a sincerity of effort measure correctly identified those giving a sincere effort in a blinded randomized control trial and second to quantify inter-rater and test-retest reliability.
  
  
  METHODS
  This article reports the findings of a two phase study. In phase one, the blinded evaluation, participants were randomly assigned to either a sincere or insincere performance condition. An examiner tested participants without knowledge of the participant's group membership. In the second phase, two examiners evaluated each participant twice to quantify inter-rater and test-retest reliability.
  
  
  RESULTS
  In the blinded phase the specificity was 100% and sensitivity was 90% for identifying sincere and insincere effort, respectively. Phase two results showed no significant difference in probability of sincere effort between raters or between testing sessions.
  
  
  CONCLUSIONS
  A performance criterion that accurately identifies sincere vs insincere group membership during functional evaluations was identified. There were no significant differences between raters or between testing sessions. These findings indicate that this test is reliable and possesses good predictive validity in assessing sincerity of effort.
authors.affiliation: Biodynamics Laboratory, The Ohio State University, Columbus, OH, USA. ferguson.4@osu.edu
authors.forename: S A
authors.initials: SA
authors.lastname: Ferguson
authors.forename: S
authors.initials: S
authors.lastname: Gallagher
authors.forename: W S
authors.initials: WS
authors.lastname: Marras
mesh_terms: D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D009068:Movement; D012680:Sensitivity and Specificity; D012984:Software