Imagined Timed Up and Go test (iTUG) in people with Parkinson's Disease: test-retest reliability and validity.

In people with Parkinson's Disease (PD), the absolute unadjusted difference (in seconds) and the absolute adjusted difference (as a percentage of estimation error) of the Imagined Timed Up and Go test (iTUG) were moderately reliable.iTUG and Imagined Box and Blocks Test (iBBT) measures were not statistically correlated. Therefore, temporal accuracy measures of Motor Imagery are highly task-dependant and thus their construct validity is poor.Correlations between the adjusted and unadjusted measures of the iTUG and the majority of clinical variables of PD were not statistically significant. Statistically significant correlations were only found between the unadjusted difference and MDS-UPDRS Part III, Schwab and England, and Berg Balance scales, as well as the adjusted difference and disease duration.