Walking motions and time-series of lower limb joint angles correlated with margin of stability

Abstract

To understand gait motions stable against fall, we computed the time-series of joint angles that are correlated with a popular kinetic gait stability index: margin of stability (MoS). A time-series extension of partial least square regression was applied on the joint angles to construct the principal motions, i.e., motion elements included in gait motions. These principal motions were linearly independent of each other and correlated with MoS. We computed the three principal motions that explain the large part of the variety of MoS using the gate database for 60 elderly people. The principal motions can be reasonably interpreted as stable gate motions in terms of MoS.