reliability of center of pressure measures in chronic stroke survivors: influence of motor and cognitive dual-tasking

 introduction: reliable balance measures are crucial for effective stroke rehabilitation. this study examines the between-day and within-day reliabilities of the center of pressure (cop) measures in chronic stroke survivors in different standing positions under the influence of motor and cognitive dual-tasking.methods: sixteen people (49.31±15.5 years, 5 females) with chronic stroke were assessed in two sessions, 48 hours apart. participants completed three balance control conditions: single-task, motor dual-task, and cognitive dual-task. they performed three trials of open-eye quiet standing and semi-tandem standing. three trials of closed-eye quiet standing were conducted in the single-task condition. a 2-way random model of the intraclass correlation coefficient (icc), standard error of measurement (sem), and minimal detectable change (mdc) were calculated for cop mean velocity, anterior-posterior (ap) and medial-lateral (ml) mean velocity, the standard deviation (sd) of ap and ml velocity, and sway area.results: within-day icc values were higher than between-day values (icc: 0.78-0.96). mean velocity and mean±sd of velocity in the ap direction showed the highest relative and absolute reliabilities in an open-eye quiet standing position (icc: 0.82-0.92, sem: 0.67-1.24). dual-tasking could increase the reliability of the cop measures, except for the sway area (icc: 0.53-0.93 changed to 0.84-0.96). mdcs ranged from 1.03 to 7.77 mm/s for velocity-based variables.conclusion: assessing the postural control system during dual-task conditions provides more reliable cop measures, especially in a semi-tandem standing position. these findings can provide clinicians with valuable insights into detecting specific balance problems that post-stroke individuals encounter.