Article

The present study was performed to evaluate and characterize the
potential of accelerometers and angular velocity sensors to detect and assess
anticipatory postural adjustments (APAs) generated by the first step at the
beginning of the gait. This paper proposes an algorithm to automatically detect
certain parameters of APAs using only inertial sensors. METHODS: Ten young
healthy subjects participated in this study. The subjects wore an inertial unit
containing a triaxial accelerometer and a triaxial angular velocity sensor
attached to the lower back and one footswitch on the dominant leg to detect the
beginning of the step. The subjects were standing upright on a stabilometer to
detect the center of pressure displacement (CoP) generated by the anticipatory
adjustments. The subjects were asked to take a step forward at their own speed
and stride length. The duration and amplitude of the APAs detected by the
accelerometer and angular velocity sensors were measured and compared with the
results obtained from the stabilometer. The different phases of gait initiation
were identified and compared using inertial sensors. RESULTS: The APAs were
detected by all of the sensors. Angular velocity sensors proved to be adequate to
detect the beginning of the step in a manner similar to the footswitch by using a
simple algorithm, which is easy to implement in low computational power devices.
The amplitude and duration of APAs detected using only inertial sensors were
similar to those detected by the stabilometer. An automatic algorithm to detect
APA duration using triaxial inertial sensors was proposed. CONCLUSIONS: These
results suggest that the feasibility of accelerometers is improved through the
use of angular velocity sensors, which can be used to automatically detect and
evaluate APAs. The results presented can be used to develop portable sensors that
may potentially be useful for monitoring patients in the home environment, thus
encouraging the population to participate in more personalized healthcare.

Langue : ANGLAIS