Enhancing Self-Efficacy Through Robotic Safety Support in Balance-Challenging Reach Tasks: Feasibility Study in Young Adults.

Background: Falls and fear of falling adversely affect the quality of life and independence of older adults. Although various robotic systems have been developed for fall prevention, their psychological effects, particularly on self-efficacy, remain underexplored. A ceiling-mounted fall impact mitigation robot offers continuous protection with almost no limitations on the range of movement; however, its impact on users' psychological state and functional performance is unclear.

Objective: This study aimed to evaluate the effect of a fall impact mitigation robot on psychological reassurance and task performance during dynamic balance tasks in healthy young adults, with a focus on self-efficacy and functional reach capacity.

Methods: Twenty-four healthy adults (age: mean 28.9, SD 7.9 years) were randomly assigned to experimental (n=12) or control (n=12) groups. All participants performed a baseline functional reach test, followed by a series of progressively challenging reach tasks (starting at 98% of maximum reach and increasing by 2% until failure). The experimental group performed tasks while wearing the fall impact mitigation robot; the control group performed without it. Self-efficacy ratings (-5 to +5 scale) were recorded before each trial. Center of pressure (COP) data were continuously collected. Statistical analyses included Mann-Whitney U tests for self-efficacy, Kaplan-Meier survival analysis for task performance, and t tests for functional reach test and COP changes.

Results: During reach trials ≥102% of baseline, the experimental group (median 1.0, IQR 0.0 to 3.0) reported significantly higher self-efficacy ratings than did the control group (median 0.0, IQR -1.0 to 2.0; U=1292.5; P=.047). However, no significant differences were observed in changes in functional reach capacity (experimental: mean 104.2%, SD 3.8%; control: mean 103.6%, SD 2.5%; P=.62) or COP displacement (experimental: mean 108.9%, SD 10.4%; control: mean 114.1%, SD 9.8%; P=.23). Survival analysis revealed a nonsignificant trend toward greater task persistence in the experimental group (χ²₁=0.36, P=.55).

Conclusions: The fall impact mitigation robot significantly improved self-efficacy during challenging balance tasks, despite providing no active physical support. These findings underscore the role of psychological reassurance in modulating balance-related behavior and suggest that robotic safety systems may influence motor performance through psychological mechanisms. Integrating psychological support into robotic fall prevention strategies may enhance their effectiveness.

Trial registration: UMIN Clinical Trials Registry UMIN000049284; https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000056126.