Novel approach for lower limb segment orientation in gait analysis using triaxial accelerometers

This paper presents a novel approach only based on triaxial accelerometers for three-dimensional (3D) orientation of lower limb segment during real-time motion. With two coaxially placed triaxial accelerometers, the actual resultant acceleration signals containing the acceleration of gravity and lineal movement along each axis were obtained. The angle displacements for orientation of each segment were calculated based on low-pass filtered accelerometer signals without integration. To evaluate accuracy, two calculated angular displacements around z, y axes during different rotational conditions were obtained and compared with the result from a high-accuracy camera system. Only based on one kind of inertial sensor, triaxial accelerometers, the approach can be used to assess spatio-temporal gait parameters and evaluate movements of each segment of the lower limbs, and thus to objectively monitor gait function of patients in a clinical setting.