Estimation of gait stability based on accelerometer signals

An estimation of gait stability based on accelerometer signal is presented. The walking process of a human body is a complex task that involves the muscular, joint and nervous systems. The gait cycle is divided into swing and stance phases. Gait stability is defined as repetition of the gait cycle with minimum variability. In order to assets the gait stability a series of parameter are estimated, such parameters include, duration of the gait cycle, length of the left and right step, average speed of the gait and number of samples per cycle. The first step toward establish gait stability is estimated the beginning and ending of a cycle. This process is achieved by a series of filter that isolated 2Hz component that is produce by heel strike. Once the cycles have been localized, the rest of the parameters are estimated. The algorithm was tested on a set of 40 healthy persons from ages 20 to 59. The results show that the stability decreases with age, as expected, since our neuromotor system deteriorates with age.