title: Postural assessment software (PAS/SAPO): Validation and reliabiliy.
abstract: OBJECTIVE
  This study was designed to estimate the accuracy of the postural assessment software (PAS/SAPO) for measurement of corporal angles and distances as well as the inter- and intra-rater reliabilities.
  
  
  BACKGROUND
  Postural assessment software was developed as a subsidiary tool for postural assessment. It is easy to use and available in the public domain. Nonetheless, validation studies are lacking.
  
  
  METHODS
  The study sample consisted of 88 pictures from 22 subjects, and each subject was assessed twice (1 week interval) by 5 blinded raters. Inter- and intra-rater reliabilities were estimated using the intraclass correlation coefficient. To estimate the accuracy of the software, an inanimate object was marked with hallmarks using pre-established parameters. Pictures of the object were rated, and values were checked against the known parameters.
  
  
  RESULTS
  Inter-rater reliability was excellent for 41% of the variables and very good for 35%. Ten percent of the variables had acceptable reliability, and 14% were defined as non-acceptable. For intra-rater reliability, 44.8% of the measurements were considered to be excellent, 23.5% were very good, 12.4% were acceptable and 19.3% were considered non-acceptable. Angular measurements had a mean error analisys of 0.11 degrees , and the mean error analisys for distance was 1.8 mm.
  
  
  CONCLUSIONS
  Unacceptable intraclass correlation coefficient values typically used the vertical line as a reference, and this may have increased the inaccuracy of the estimates. Increased accuracies were obtained by younger raters with more sophisticated computer skills, suggesting that past experience influenced results.
  
  
  CONCLUSIONS
  The postural assessment software was accurate for measuring corporal angles and distances and should be considered as a reliable tool for postural assessment.
authors.affiliation: Department of Physical Therapy, Communication Science & Disorders, Universidade de São Paulo, SP, Brazil. elferreira@usp.br
authors.forename: Elizabeth Alves G
authors.initials: EA
authors.lastname: Ferreira
authors.forename: Marcos
authors.initials: M
authors.lastname: Duarte
authors.forename: Edison Puig
authors.initials: EP
authors.lastname: Maldonado
authors.forename: Thomaz Nogueira
authors.initials: TN
authors.lastname: Burke
authors.forename: Amelia Pasqual
authors.initials: AP
authors.lastname: Marques
mesh_terms: D000328:Adult; D001837:Body Weights and Measures / Q000295:instrumentation; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D015588:Observer Variation; D011187:Posture / Q000502:physiology*; D012016:Reference Values; D015203:Reproducibility of Results; D012986:Software Validation; D013997:Time Factors; D055815:Young Adult