Shared roles of motor, sensory, and cognitive functions in challenging functional mobility tasks.

Age-related declines in motor (MF), cognitive (CF), and sensory functions (SF) can impact functional mobility. Understanding their interactive contributions across mobility tasks may inform effective interventions for older adults.

Purpose: This study examined the distinct and shared contributions of MF, CF, and SF to functional mobility performance under basic and challenging conditions in older adults.

Methods: A total of 141 community-dwelling older adults (age=76 ± 7 years) completed comprehensive assessments of MF, CF, and SF. Functional mobility was evaluated using single-task and dual-task Timed Up and Go (TUG) tests, and usual and fastest walking tests. Linear mixed-effects models and commonality analysis examined relationships between functions and mobility performance.

Results: CF significantly influenced TUG performance, particularly under dual-task conditions (β=-2.21, p = 0.007, η²p = 0.07), while MF primarily affected walking speed, especially during fastest-speed trials (β=0.08, p = 0.009, η²p = 0.06). Shared contributions of CF and MF explained substantially more variance in dual-task TUG (31.22 %) and fastest walking (41.91 %) than their distinct contributions (5.56 % and 4.04 %, respectively). SF showed minimal impact on functional mobility tasks.

Conclusion: In community-dwelling older adults, CF predominantly influences dual-task TUG performance, while MF appears to be the primary factor in fastest walking. The substantial shared contributions of CF and MF to challenging mobility tasks suggest that integrated interventions targeting both functions may be more effective for enhancing functional mobility than approaches focusing on individual domains.