Correspondence:
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Corresponding author: Joan M. Stevenson, School of Physical and Health Education, Queen's University, Kingston, Ontario K7L 3N6, Canada. Fax: +1 613 545 2009
Abstract: The purpose of this study was to develop and validate a one camera analysis strategy to correct for the effects of perspective error due to out of plane rotation on the calculation of L4/L5 moment and compression and shear forces. A mathematical model was derived around the geometric relationship of a T-Bar shaped device and the measured camera to object plane distance. This geometric relationship was used to reorient a rotated subject back into the perpendicular film plane before calculation of joint moments and forces. Systematic errors (rotational perspective errors, forward/backward and side/side distances of subject from camera) and random errors (digitization error, anthropometrics, lifting techniques) were determined with maximum errors of 10.5%, within ±20 degree out of plane rotations. Results generally supported incorporation of a correctional device to extend the use of two-dimensional analysis strategies in industrial settings.
