Analysis of Human Gait Based on Smartphone Inertial Measurement Unit: A Feasibility Study

In that feasibility study we report on the capability of the inertial measurement units embedded in a smartphone to adequately reconstruct the spatio-temporal trajectory of human head during a widely used the Timed Up and Go (TUG) motor test. The data obtained with the help of a commercially available motion stereo video capture system served as the reference. We found that the trajectories reconstructed from the signals of 3-axial accelerometer and gyroscope of a smartphone matched well with those obtained by a conventional video system. In the time domain this matching was clearly high, while in the spatial domain there were inconsistencies between two methods seen at the “sit-to-stand” and “stand-to-sit” phases. In conclusion, the smartphone's sensor system efficiently reconstructed the spatio-temporal trajectories. Therefore, even relatively cheap MEMS sensors can be used for the purpose of reliable motion analysis, especially in the condition when the body effectively damps mechanical shocks and vibrations during the TUG test. Vertical human movements during walking can be measured even by inertial sensors in smartphones with rather low cut-off frequencies (15–25 Hz).