The reliability of quantifying upright standing postures as a baseline diagnostic clinical tool.

To assess the reliability of posture across and within subjects, specifically the repeatability of spinal angles determined by digitization of images in the anterior, posterior, and sagittal views.

A repeated measure design was used in which subjects were required to attend 3 sessions, each consisting of 3 trials. Photographs of the anterior, posterior, and lateral views of normal, relaxed upright standing were taken during each trial. Landmarks were digitized and cervical, thoracic, and lumbar angles were calculated with respect to a vertical reference line.