title: A single video camera postural assessment system to measure rotation of the shoulder during computer use.
abstract: The goal of this study was to evaluate the performance of a single video camera system for measuring shoulder rotation during computer work, and to quantify the work and postural space within which the system performs optimally. Shoulder rotation angles calculated using the video system were compared with angles calculated using an active infrared LED three-dimensional motion analysis system while 10 adult volunteers simulated postures for two different trials: typical of normal computer work (freestyle) and with forced shoulder abduction (constrained). Average and absolute errors were calculated to determine the accuracy and precision of the system, respectively, for each trial, for each position, and for both the right and left hands. For the right hand, mean values for the average and absolute errors were -1 and 0 degrees, respectively. Only the absolute error increased significantly to 12 degrees for the constrained posture compared with freestyle. During normal computer work, the video system provided shoulder rotation angle values similar to those of a three-dimensional system, thus making it a viable and simple instrument to use in field studies.
authors: Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA.
authors: Jennifer L
authors: JL
authors: Bruno
authors: Zhizhong
authors: Z
authors: Li
authors: Matthieu
authors: M
authors: Trudeau
authors: Sachin M
authors: SM
authors: Raina
authors: Jack T
authors: JT
authors: Dennerlein
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D009068:Movement / Q000502:physiology*; D010781:Photography / Q000379:methods*; D011187:Posture / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology*; D012785:Shoulder Joint / Q000502:physiology*; D014741:Video Recording / Q000379:methods*