Development of an Automated Method to Detect Sitting Pivot Transfer Phases Using Biomechanical Variables: Toward a Standardized Method
By Desroches, Guillaume; Vermette, Martin; Gourdou, Philippe; Gagnon, Dany; Journal of NeuroEngineering and Rehabilitation, Volume 9, Number 7Publication Date: February 3, 2012
Study developed and tested a relative threshold-based algorithm to automatically detect four distinct sitting pivot transfer (SPT) phases using kinematic and kinetic event markers. The study was undertaken to gain a better biomechanical understanding of the different SPT phases for the purpose of improving the teaching of this task to individuals with spinal cord injury (SCI). Study participants were 35 manual wheelchair users with SCI with a mean age of 43.5 years, 3 of whom were women. Participants performed two SPTs between seats of similar height using their usual SPT technique. Kinematics and kinetics were recorded using an instrumented transfer assessment system consisting of 4 Optotrak Model 3020 and 2 Optotrak Certus synchronized camera units. Based on kinetic and kinematic measurements, a relative threshold-based algorithm was developed to identify 4 distinct phrases: pre-lift, upper arm loading, lift-pivot, and post-lift phases. To determine the stability of the algorithm between the two SPTs, Student t-tests for dependent samples were performed on the absolute duration of each phase. The mean total duration of the SPT was 2.00 seconds. The mean duration of the pre-lift, upper arm loading, lift-pivot, and post-lift phases were 0.74 seconds, 0.28 seconds, 0.72 seconds, and 0.27 seconds, whereas their relative contributions represented approximately 35, 15, 35, and 15 percent of the overall SPT cycle, respectively. No significant differences were found between the trials. Overall, the relative threshold-based algorithm used to automatically detect the four distinct phases of the SPT was rapid, accurate, and repeatable.
Published by: BioMed Central Ltd (Website:http://www.biomedcentral.com)
Link to text: http://www.jneuroengrehab.com/content/pdf/1743-0003-9-7.pdf
