A novel approach in objective assessment of functional postural responses during fall-free perturbed standing in...

The proposed approach offers few novelties in integration of objective assessment of postural responses when an unexpected perturbation is applied to the standing person into the existing rehabilitation therapy. The research apparatus was equipped with electrical actuators to provide unexpected perturbations (controllable and repeatable strength and duration) to the standing frame in eight directions during quiet standing in a fall-safe environment. During the perturbations ground reaction forces were recorded under each foot and the motion of center of pressure was derived to extract the postural response indicators in time and space domain. Seven neurologically intact subjects participated in normative set up that was used to develop an algorithm for selective postural response characteristics analysis for each perturbation direction. The postural responses in two incomplete spinal cord injured persons and hemiparetic stroke patient were investigated and contrasted to the normative responses to test the proposed approach. The outcomes of the investigation showed expected distinctive direction-dependent postural responses characteristic for hemiparetic subjects. Our observations suggest that the approach may become effective in substantial quantitative multidirectional stabilometric evaluation of functional postural responses, especially when the effectiveness of the balance training rehabilitation program is in need for objective evaluation. Simultaneously the apparatus can be used also for the balance training and therefore become a training and assessment tool for clinical and home environment.