Oral-motor complexity influences center of pressure patterns in adults with stroke-related communication disorders

Abstract

People with stroke (PwS) often exhibit altered postural control, and concomitant stroke-related communication disorders (e.g., aphasia, dysarthria) may be an underrecognized risk factor for post-stroke falls. This heightened fall risk may be related to alterations in postural control that emerge during different speaking and listening conditions. This study evaluated how variations in the relative articulatory demands during speech production-termed "oral-motor complexity"-affect postural center of pressure (COP) patterns among PwS, both with communication disorders (PwS-CDis) and without (PwS). Three groups of adults (PwS, PwS-CDis, and a nondisabled Control group) stood on a force platform while completing four 30-second quiet stance trials, followed by twelve 30-second trials randomized across three experimental conditions of varying oral-motor complexities ("ba", "puh tuh kuh", "rah shah lah nah"). COP variability (SD) was significantly higher during experimental conditions compared to quiet stance, regardless of group and movement plane. Differences in nonlinear time-dependent metrics were found across oral-motor task conditions, particularly among PwS-CDis, suggesting oral-motor complexity may influence underlying postural-motor organization. Distinct temporal-dynamical patterns observed in PwS-CDis indicate a possible link between pathology, postural control, and speech motor tasks, which is relevant when evaluating postural control in individuals with stroke-related communication disorders.