Do wearable sensors add meaningful information to the timed up and go test? A study on obese women

The purpose of this study was to validate Time Up and Go test (TUG) as measured by a single Inertial Measurement Unit (IMU) placed on the lower back to that measured by a stopwatch in obese and normal weight women; in addition, the comparison of the performance of TUG WA between obese and healthy women using the instrumented TUG (iTUG). Forty-four severely obese women and 14 age-matched healthy women were assessed simultaneously by IMU and stopwatch. The comparison between manual and instrumented assessment of total time duration showed no significant differences both in the healthy (8.32 +/- 0.96 s vs. 8.52 +/- 0.97 s, p > 0.05) and in the obese group (9.99 +/- 2.28 s vs. 9.81 +/- 2.52 s; p > 0.05). The comparison between obese and healthy group exhibited significant differences in terms of total time duration both during manual and iTUG, which is longer in obese women than normal weight women. The duration of the sub-phases in obese group is longer with the exception of sit-to-stand and stand-to-sit phase, with lower turning velocity both in mid- and final turning sub-phase. The results suggest that the iTUG is an objective and fast mobility test and it could add useful information to the manual TUG for clinical practice.