Pj. Klein et Jj. Dehaven, ACCURACY OF 3-DIMENSIONAL LINEAR AND ANGULAR ESTIMATES OBTAINED WITH THE ARIEL PERFORMANCE ANALYSIS SYSTEM, Archives of physical medicine and rehabilitation, 76(2), 1995, pp. 183-189
Computer-assisted video motion analysis is a method of evaluating huma
n kinematics that offers promise both for research and for clinical ap
plication. This study determined the upper limits of accuracy and cons
istency of linear and angular measures obtained using the Ariel Perfor
mance Analysis System. Reference standards included a meter stick and
a universal 360-degrees goniometer. Average mean error observed for re
construction of absolute point estimates was found to be less than 3.5
mm. Mean error estimate for three-dimensional (3D) reconstruction of a
linear standard was found to be 1.4mm (SD 0.30). Average mean angular
error observed for 3D reconstruction of goniometer settings 10-degree
s to 170-degrees was found to be 0.26-degrees (mean SD 0.21). System u
sers are cautioned that some increased error associated with software
derivation of joint angles exists as angles approach 180-degrees, use
of wide-angle lens accessories introduces a systematic field-dependent
bias; and planar rotation introduces some (<2-degrees) random error.