Association between risk of fall and postural displacement speed in individuals with stroke

Abstract

Introduction: Stroke can generate sequelae that negatively influence postural control, making individuals susceptible to falls, and negatively impacting the quality of life of these subjects. The ability to maintain postural stability has been assessed through clinical trials, such as the Berg Balance Scale (BBS), or through posturography, in which measurement and recording of foot pressure center displacements (CP) are analyzed. Among the different variables estimated by posturography, the CP velocity profile has been sensitive to changes in postural control in different populations. Objective: The present study aims to investigate the relationship between CP velocity profile and BBS clinical test performance in post-stroke individuals. Methods: A cross-sectional observational study was performed, and the sample (n = 39) consisted of individuals with clinical diagnosis of stroke for more than six months. Subjects were submitted to a clinical evaluation, which included BBS, and a posturographic evaluation, consisting of the maintenance of the orthostatic position for 60s, with the feet positioned comfortably, arms relaxed and eyes fixed on a target in front of the evaluated one. The posturographic analysis includes parameters like mean velocity in the anterior-posterior [VMAP] and medial-lateral [VMML] directions) and high-speed regions [HSR] 3D statokinesiograms. Spearman correlation analysis (rho) was used, assuming =5%. The 95% confidence interval (IC95) of the correlation coefficients were estimated. Data are presented as median (lower quartile-upper quartile). Results: Spearman's correlation analysis shows a significant and inverse association between CP velocity profile and BBS performance: VMAP vs. BBS, rho = -0.40, p = 0.003, IC95[-0.64 - -0.12]; VMML vs. BBS, rho = -0.44, p = 0.001, IC95 [-0.67 - -0.15]; nHSR vs. BBS, rho = -0.34, p = 0.012, IC95 [-0.59 - -0.06]. Conclusion: The CP velocity profile is negatively associated with performance in postural stability tests in post-stroke individuals, indicating that the higher the CP displacement velocity, the greater the postural control loss and the greater the risk of fall in this population.