Detecting spinal posture change in sitting positions with tri-axial accelerometers

A method of using three tri-axial accelerometers for monitoring postural changes in sitting was introduced. Subjects were requested to perform for-ward trunk flexion and lateral bending. A motion analysis system and a three-dimensional rotation alignment device were used to verify the measurements of the accelerometers. The precision and reliability of the accelerometers for measuring static calibration was demonstrated as <= 1 degrees for the RMS error and 1.000 for ICC(3, 1). For measurements of sitting posture, the averaged RMS difference between the measurements of the accelerometers and the motion analysis system were <= 5 degrees for all sittin- postures on the coronal and sagittal planes. The results of this study demonstrated that tri-axial accelerometers could be used for tracking spinal postural changes on the sagittal and coronal planes in the sitting positions. (C) 2007 Elsevier B.V. All rights reserved.