Feature Selection for the instrumented Timed Up and Go in Parkinson’s disease

The Timed Up and Go (TUG) is a widely used clinical test to assess mobility and fall risk in Parkinson’s disease (PD). The traditional outcome of this test is its duration. Since this single measure cannot provide insight on subtle differences in test performances, we considered an instrumented TUG (iTUG). The aim was to find, by means of a feature selection, the best set of quantitative measures that would allow an objective evaluation of gait function in PD. We instrumented the TUG using a triaxial accelerometer. Twenty early-mild PD and twenty age-matched control subjects were tested. The resulting selected features are all accelerometer-derived measures: they permit to obtain a good accuracy (7.5% of misclassification rate) in the classification of PD. Interestingly the traditional TUG duration was not selected in the best subsets.