How a predictive analysis can be used to assess which hemiparetic patients can gain advantage from additional visual feedback of center-of-pressure displacements?

Past studies have emphasized that hemiparetic stroke patients do not always take advantage from additional visual feedback (VFB) of center-of-pressure displacements in undisturbed upright stance. This study was designed to assess the best parameters (area and variances along medio-lateral and antero-posterior axes of the center-of-pressure displacements) that could predict this capacity to take advantage from VFB and to identify the patients who would be capable of positively using it to improve balance control. The postural behaviors of thirty-nine patients were recorded. Patients were evaluated in two randomly experimental conditions (eyes open with and without additional visual feedback). A predictive analysis was computed to evaluate the interest of using the VFB during rehabilitation through the knowledge of positive and negative predictive values. Lateral instability (mediolateral variance of the center-of-pressure displacements), the main postural deficiency in hemiparetic patients, was the most efficient parameter for predicting the consequences of using VFB postural control. Patients with a low mediolateral variance do not have benefit from VFB technique for stance rehabilitation. The less stable hemiparetic patients, characterized in our case by medio-lateral variances superior to a 23 mm2 threshold, gain advantage to VFB technique. The decision of when to provide or not this additional sensory information could be relevant in order to optimize the balance rehabilitation protocols