The Institute of Human Movement Sciences and Sport (ETH Zürich), has published results using Physilog sensors for the instrumented Timed Up and Go (iTUG): “Reliability and validity of the inertial sensor-based Timed “Up and Go” test in individuals affected by stroke“. The article is published in the Journal of Rehabilitation Research & Development (JRRD) by the U.S. Department of Veterans Affairs.

Contact Gait Up for information regarding the Physilog sensor configuration used in the study. Gait Up’s Gait Analysis Package, which can be used to perform the iTUG, is available for purchase directly from Gait Up’s online web shop.


The instrumented Timed “Up and Go” test (iTUG), based on body-fixed Physilog sensors, has the potential for playing an important role in providing clinically useful information regarding an individual’s balance and mobility that cannot be derived from the original single-­outcome Timed “Up and Go” test protocol. The purpose of this study was to determine the reliability and validity of the iTUG in people affected by stroke. For test-retest reliability analysis, 14 individuals with stroke and 25 nondisabled elderly patients were assessed. For validity analysis, an age-matched comparison of 12 patients with stroke and 12 nondisabled controls was performed. Out of 14 computed iTUG metrics, the majority showed excellent test-retest reliability expressed by high intraclass correlation coefficients (range 0.431 – 0.994) together with low standard error of measurement and smallest detectable difference values. Bland-Altman plots demonstrated good agreement between two repeated measurements. Significant differences between patients with stroke and nondisabled controls were found in 9 of 14 iTUG parameters analyzed. Consequently, these results warrant future application of the inertial sensor-based iTUG for the assessment of physical deficits post stroke in longitudinal study designs.


Excellent test-retest reliability was found for most of the iTUG metrics measured, and the inertial sensor-based iTUG is able to distinguish patients with stroke from nondisabled controls.These findings suggest that the inertial sensor-based iTUG measures are useful to assess functional mobility in patients with stroke. However, the study should be repeated with a larger group of patients to investigate it’s discriminatory capabilities between different subgroups of stroke patients.