Effect of dual tasking on intentional vs. reactive balance control in people with hemiparetic stroke

Abstract

To examine the effect of a cognitive task on intentional vs. reactive balance control in people with hemiparetic stroke (PwHS). Community-dwelling PwHS (n = 10) and healthy, age-similar controls performed two tests, which included the Limits of Stability Test (intentional control) and the Motor Control Test (reactive control), under single-task (ST) and dual-task (DT) conditions (addition of a cognitive task). Cognitive ability was measured on a word list generation task by recording the number of words enumerated in sitting (ST; for cognition) and during the balance tasks. The difference in response time between the ST and DT, defined as the "balance cost" was obtained [(ST - DT)/ST × 100] and compared between tests and across groups. The "cognitive cost" was similarly defined and compared. For both groups, the response time under DT condition was significantly greater for intentional than the reactive balance control task, leading to a higher balance cost for this task (P < 0.05). However, the cognitive cost was significantly greater for the intentional than the reactive balance control task for only the PwHS. DT significantly affected intentional than reactive balance control for PwHS. The significant decrease in both balance and cognitive performance under DT compared with ST conditions during intentional balance control suggests sharing of attentional resources between semantic memory and intentional balance control. Decreased performance on the cognitive task only during the reactive balance test indicates possible central nervous system's prioritization of reactive balance control over cognition.

Attentional Demands of Perturbation Evoked Compensatory Stepping Responses: Examining Cognitive-Motor Interference to Large Magnitude Forward Perturbations

“…In contrast to our findings, previous studies examining the cognitive-motor interference of reactive balance have demonstrated that dual tasking affects the performance only on the cognitive task (motor-related cognitive interference) without affecting the reactive balance task (Brauer et al, 2002;Maki et al, 2001;Zettel et al, 2008). As most of these studies have examined the cognitive-motor interference using small magnitude perturbations, it is postulated that the individuals are able to rapidly switch attention to the reactive balance task, and maintain postural stability at the cost of the cognitive task performance when perturbing intensities are small (Brauer et al, 2002;Brown et al, 1999;Maki & McIlroy, 2007;Maki et al, 2001;Subramaniam, Hui-Chan, & Bhatt, 2014;Zettel et al, 2008).…”

Effect of Contextual Interference in the Practicing of a Computer Task in Individuals Poststroke

“…Individuals in the SG took more time to perform the maze task as compared with the CG in most stages of the practice. This finding is interpreted as a consequence of the lesion in brain areas (e.g., the cerebral cortex) [52] that might negatively affect the planning and execution of motor tasks that requires spatial memory and organization [39]. It is well known that the ability to find the right way into a novel or familiar environment (such as in the maze task) is a multifactorial function [53].…”

Effects of intensive multiplanar trunk training coupled with dual-task exercises on balance, mobility, and fall risk in patients with stroke: a randomized controlled trial

“…7 Nevertheless, traditional rehabilitation programs do not generally include DT as a therapeutic strategy during therapeutic training. 8 Studies examining postural control and balance activities following a stroke have reported that DT exercises substantially deteriorate both motor and cognitive components of balance control owing to cognitive-motor interference (CMI), [9][10][11] that is, a decline in the performance of one or both (cognitive and motor task) components, relative to the performance of each task component separately during DT performance. CMI also considerably affects gait parameters following stroke, such as decreased gait speed and increased stride duration.…”

“…Studies examining postural control and balance activities following a stroke have reported that DT exercises substantially deteriorate both motor and cognitive components of balance control owing to cognitive–motor interference (CMI), 9 – 11 that is, a decline in the performance of one or both (cognitive and motor task) components, relative to the performance of each task component separately during DT performance.…”