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Effect Of Predictability Of The Magnitude Of A Perturbation On Anticipatory And Compensatory Postural Adjustments, Tippawan Kaewmanee, Huaqing (Virginia) Liang, Alexander S. Aruin

Physical Therapy Faculty Research

Balance maintenance in response to a perturbation could be affected by the predictability of the magnitude of the body disturbance. We investigated anticipatory (APAs) and compensatory (CPAs) postural adjustments in response to perturbations of predictable and unpredictable magnitudes. Twenty young adults received series of perturbations of small or large magnitudes the order of which was varied. Electromyographic activity of six leg and trunk muscles and displacements of the center-of-pressure (COP) were recorded. The muscle onset time, integrals of muscle activity, and COP displacements in the anterior–posterior direction were analyzed during the APA and CPA phases. The results indicated that when …