A new portable device for assessing locomotor performance.

We investigated the validity of a new portable system and the feasibility of the method for gait analysis as the assessment of gait has clinical relevance in the study of locomotor pathologies. This system is composed of a data logger, triaxial accelerometers, and software. Measurements of the pelvis kinematics during gait were performed on five hip osteoarthritic subjects and 15 healthy subjects using the portable system and a reference system (Vicon). The healthy subjects were studied in conditions of normal gait and gait altered by a heelpiece. The studied variables were the vertical amplitude of the sacrum, the time of gait cycle and the vertical trajectories of the spines. The new system corresponded with the reference system for the studied variables. The small differences between the two systems in the vertical amplitude of the sacrum (0.53 +/- 6.39 mm), time of the gait cycle (0.002 +/- 0.05 s), and the vertical trajectories of the spine (coefficient correlation of 0.06 +/- 0.05) confirmed the validity of the portable system data. The results showed a distortion of the pelvis trajectory when the gait was impaired. The portable system provides an objective method to discriminate normal from limping gait and is easy to use outside of the laboratory.