Use of wearable inertial sensor in the assessment of Timed-Up-and-Go Test: Influence of device placement on temporal variable estimation

The “Timed Up and Go” (TUG) test is widely used in various disorders to evaluate subject’s mobility, usually evaluating only time execution. TUG test specificity could be improved by using instrumented assessment based on inertial sensors. Position of the sensor is critical. This study aimed to assess the reliability and validity of an inertial sensor placed in three different positions to correctly segment the different phases in the TUG test. Finding demonstrated good reliability of the proposed methodology compared to the gold standard motion analysis approach based on surface markers and an optoelectronic system. Placing the sensor just beneath the lumbar-sacral joint reported the lower values of deviation with respect to the gold standard. Optimized position can extend the proposed methodology from the clinical context towards ubiquitous solutions in an ecological approach.