Estimation of Mediolateral Gait Postural Stability using Time-Series Pelvis Angular Velocities

Gait stability indices play an important role in both clinical and commercial applications and are effective for estimating an individual’s fall risk. In general, the computation of gait stability indices requires motion-capture systems to measure the positions and angles of multiple body segments. If the stability indices can be estimated from the time-series data of a single body segment, they can be easier to access. We used principal motion analysis to estimate the margin of stability, which is a popular gait stability index, based on the time series of the angular velocities of the pelvis during walking. The linear combination of three principal motions could estimate the minimum margin of stability along the mediolateral direction with a correlation coefficient of 0.58. The angular velocities of the pelvis can be used to estimate gait stability independently or in conjunction with other kinematic information.