title: The reliability and validity of the Saliba Postural Classification System.
abstract: OBJECTIVE
  To determine the reliability and validity of the Saliba Postural Classification System (SPCS).
  
  
  METHODS
  Two physical therapists classified pictures of 100 volunteer participants standing in their habitual posture for inter and intra-tester reliability. For validity, 54 participants stood on a force plate in a habitual and a corrected posture, while a vertical force was applied through the shoulders until the clinician felt a postural give. Data were extracted at the time the give was felt and at a time in the corrected posture that matched the peak vertical ground reaction force (VGRF) in the habitual posture.
  
  
  RESULTS
  Inter-tester reliability demonstrated 75% agreement with a Kappa = 0.64 (95% CI = 0.524-0.756, SE = 0.059). Intra-tester reliability demonstrated 87% agreement with a Kappa = 0.8, (95% CI = 0.702-0.898, SE = 0.05) and 80% agreement with a Kappa = 0.706, (95% CI = 0.594-0818, SE = 0.057). The examiner applied a significantly higher (p < 0.001) peak vertical force in the corrected posture prior to a postural give when compared to the habitual posture. Within the corrected posture, the %VGRF was higher when the test was ongoing vs. when a postural give was felt (p < 0.001). The %VGRF was not different between the two postures when comparing the peaks (p = 0.214).
  
  
  CONCLUSIONS
  The SPCS has substantial agreement for inter- and intra-tester reliability and is largely a valid postural classification system as determined by the larger vertical forces in the corrected postures. Further studies on the correlation between the SPCS and diagnostic classifications are indicated.
authors: Physical Therapy Department, Long Island University, 1 University Plaza, Brooklyn 11201, NY, USA.
authors: Cristiana Kahl
authors: CK
authors: Collins
authors: Institute of Physical Art, 43449 Elk Run, Steamboat Springs 80487, CO, USA.
authors: Vicky Saliba
authors: VS
authors: Johnson
authors: Physical Therapy Department, Long Island University, 1 University Plaza, Brooklyn 11201, NY, USA.
authors: Ellen M
authors: EM
authors: Godwin
authors: Faculty of Health Sciences, Discipline of Physiotherapy, University of Sydney, 75 East St, Lidcombe 2141, NSW, Australia.
authors: Evangelos
authors: E
authors: Pappas
keywords: Postural alignment; Postural classification; Postural stability; Posture