Additional Nexus reference PDFs:

Nexus legacy documentation:

This information is for Vicon Nexus 2.5. For up-to-date help, see the latest Nexus documentation.

Nexus PDFs

Location: Pipeline Tools pane > Available Operations list > Data Processing > Calculate Gait Deviation Index operation

The Gait Deviation Index (GDI) is "a multivariate measure of overall gait pathology..." formed from "...a set of mutually independent joint rotation patterns that efficiently describe gait" (Schwartz and Rozumalski, 2008, see References below). 

Nexus now provides a new pipeline operation that produces a GDI score for the subject of the current trial.

For summary information on the Advanced Properties for this operation, view the tooltips by hovering the mouse pointer over the relevant field. As these properties are derived from the original publication referenced below, for more detailed information, see the original publication.

When you run the Calculate Gait Deviation Index operation on a trial, two GDI values (left and right), are output to the log and saved as subject parameters.

You can output these values when you run the Export ASCII pipeline operation by selecting the Export Gait Cycle Parameters option.


The following research publication provides supporting information on the scientific basis and validation of Vicon's implementation of the calculation of the GDI score:

  • SCHWARTZ, M. H., and ROZUMALSKI, A., The gait deviation index: A new comprehensive index of gait pathology, Gait & Posture 28 (2008), p351–357.