Individuals with stroke-related communication disorders alter postural control in response to speech motor task demands

This study evaluated how varying the difficulty of speech motor task demands influences center of pressure (COP) patterns among PwS with stroke-related communication disorders and PwS without communication disorders, compared to a nondisabled control group.

Three groups of middle-aged adult participants (PwS without communication disorders, PwS with stroke-related communication disorders, and a nondisabled control group) stood on a force plate while COP was continuously recorded. Participants completed four 30-second quiet stance trials, followed by twelve 30-second trials randomized across three experimental conditions. These experimental conditions involved repetition of novel nonsense syllables of varying levels of speech motor task difficulty. Mixed effects modeling was used to determine differences in COP patterns (both in terms of magnitude and temporal regularity) between groups and speech task conditions.

COP magnitude (i.e., sway variability) was greater in all speech task conditions compared to quiet stance (p .001), regardless of group and plane of movement (i.e., anteroposterior vs. mediolateral). For COP temporal regularity measures, only individuals with stroke-related communication disorders demonstrated shifts in COP patterns as speech motor task demands changed. Changes in COP patterns were suggestive of alterations in the underlying flexibility and adaptability of postural control.

Speech motor task demands may affect the underlying control and organization of the postural control system, particularly among PwS with stroke-related communication disorders. Distinct patterns of postural dynamics in PwS with stroke-related communication disorders suggest a possible link between pathology, postural control, and speech motor tasks after stroke. This underscores the importance of physical therapists evaluating and treating individuals post-stroke across multiple task contexts to fully address factors influencing postural control.

These findings emphasize the need for tailored rehabilitation and evaluation methods that address the multifaceted balance and postural control challenges faced by individuals with stroke-related communication disorders. The connection between speech motor control and postural control offers promising opportunities for enhanced interdisciplinary clinical collaboration between physical therapists and speech-language pathologists.