Evaluation of agreement between static posturography methods employing tensometers and inertial sensors

This study investigates the agreement between two methods used for the assessment of human balance system. Static posturography based on tensometers, using a commercially available platform, is used as the reference method. An alternative approach is a portable prototype MediPost system that utilises inertial sensors developed by the authors. Both approaches determine the movement of the subject's centre of mass, quantifying this movement in terms of angular speed. Data for the evaluation of agreement were obtained from 205 subjects, with each subject simultaneously tested with both methods. During the tests, the subject performed a set of standard procedures involving quiet standing in an upright position. In order to verify the agreement between the evaluated methods, the Bland-Altman, concordance correlation and intraclass correlation coefficients were used. In addition, the trajectories of the centre of gravity were compared. The obtained results show good agreement between the verified methods, even though they are based on different physical phenomena.