This study aimed to clarify the characteristics of bimanual coordination in frail older adults.
The study involved 312 community-dwelling older adults, divided into robust, pre-frail, and frail groups using the Kihon Checklist. All participants performed bimanual coordination tasks, consisting of an in-phase task of tapping with the thumb and index finger as quickly as possible on both hands simultaneously, and an anti-phase task of alternating tapping with both hands. Each task was performed for 15 seconds with eyes closed. Eight features were measured: total traveling distance, mean and standard deviation of local maximum distance, slope of approximate line of local maximum points, number of taps, mean and standard deviation of tap intervals, and frequency of taps. Three-way ANOVA was used to compare each feature among groups, hands, and tasks, with a significance level of 5%.
Based on the Kihon Checklist, 129 participants were classified as robust, 136 as pre-frail, and 47 as frail. Statistical analysis revealed no significant interaction between group, side, and task factors across the eight measured metrics (p > 0.05). However, the total traveling distance showed a significant main effect for the group factor, with the frail group demonstrating a significant reduction in movement distance compared to the robust group (p 0.05).
Frailty is characterized by increased vulnerability due to decreased muscle strength and endurance, which leads to slower movement speed. As a result, the bimanual coordination speed likely decreased in frail older adults, reducing total traveling distance. Furthermore, interhemispheric interactions via the corpus callosum play an important role in bimanual coordination, and structural changes in the corpus callosum are significant in frail older adults. Therefore, the decline in bimanual coordination performance in frail older adults may be attributed to structural and functional changes in the corpus callosum.
The results of this study suggest that bimanual coordination could be applied as an assessment index for frailty.
bimanual coordination
finger tapping