Dual-Task Stepping in Stroke Survivors

Background and Aims: Falling has been identified as a major complication in stroke survivors. If balance is lost, quick step execution can prevent falls. The aim of the present study was to investigate voluntary stepping behavior in stroke survivors under single-and dual-task conditions compared to healthy controls. In addition we compared involved vs. uninvolved legs of stroke survivors. Methods: Sixteen chronic stroke survivors and sixteen healthy controls performed Voluntary Step Execution Test as a reaction time task under two conditions: (1) single task and (2) as in (1) while performing an attention-demanding task (dual task). Step initiation. Preparatory phase, Swing phase, and stepping time, were extracted from center of pressure and ground reaction force plate data. In the second stage of the study 10 different stroke survivors performed Voluntary Step Execution Test with the involved and uninvolved legs. Results: Chronic stroke survivors were significantly slower than healthy controls in all step parameters under single-and dualtask conditions. Involved legs of stroke survivors had a significantly slower stepping time than uninvolved leg in both task conditions due to increased swing phase duration. For dual compared to single task, the stepping time increased significantly in involved and uninvolved legs due to increased step initiation phase duration. Conclusions: Stroke survivors are at a greater risk of falling especially to the involved side in dual-task condition. The inability to swing the involved leg quickly may be the most significant factor contributing to the large number of falls seen in stroke survivors.