Article

The Gillette Gait Index uses principle components analysis of 16 variables to
determine the deviation of an individual's gait compared to a normal control set.
Previous literature has not reported on the effects of altering the size of the
control set used to create the principle components, or described the effects of
using less than the maximum number of principle components, 16, to calculate the
Gillette Gait Index (GGI). Calculations of the GGI were determined for a group of
24 able-bodied normal subjects and 24 cerebral palsy subjects using 128 control
subjects allotted into 15 subsets of varying sizes, from N=16-128. A minimum of
40 controls were needed for GGI estimates to achieve less than approximately 20%
error, and 96 controls were needed for less than 10% error, if all 16 principle
components were used. With smaller control sets, an alternative method to
increase the accuracy would be to use only those principle components that
represent 95% of the variance. Caution must still be used when describing
differences in GGI among groups, or changes in an individual's GGI over time. In
addition, absolute changes in GGI should always be reported, as differences as
great as 150 were seen in cerebral palsy patients across control groups, even
when greater than 40 controls are used to create the principle components.

Langue : ANGLAIS