The Effects of Real-Time Haptic Feedback on Gait and Cognitive Load in Older Adults.

Gait speed is a key indicator of mobility and health in older adults, with declines often reflecting neuromotor deficits rather than musculoskeletal or cardiopulmonary limitations. This study presents a wearable smartphone-based haptic feedback system that applies feedback to the thighs to increase peak thigh extension (PTE) and, consequently, improve stride length and walking speed. Thirty community-dwelling older adults ( ${79}.{9}~ {\pm }~{6}.{5}$ years) participated in this study. Three treatment conditions were evaluated: (1) tactile feedback due to incorrect response when PTE was below the target ( ${F}_{\text {IR}}$ ); (2) tactile feedback due to correct response when the target PTE was met ( ${F}_{\textit {CR} }$ ); and (3) verbal instructions ( ${I}_{\boldsymbol {V}}$ ) without feedback. Cognitive demand during treatment was assessed using a probe reaction time task. Walking trials comparing baseline with treatment conditions were conducted. We found significant differences for all gait parameters across walking trials ( $\mathit {p} \lt {0}.{001}$ ), but no significant difference among the three treatment conditions. The haptic feedback system significantly increased stride length by 14% and gait speed by 18%. Gains in speed and stride length were achieved using the haptic system during a single session, comparable to following verbal instructions. Although no statistical difference was found across treatments, thigh feedback employed a different mechanism than verbal instructions for attaining greater speed. Adding haptic feedback increased reaction time, but these increases were small ( ${F}_{\textit {IR} }$ : 27ms, ${F}_{\textit {CR} }$ : 74ms), indicating minimal cognitive load. The observed gait improvements suggest haptic feedback is a viable option for gait training for older adults.