Different haptic tools reduce trunk velocity in the frontal plane during walking, but haptic anchors have advantages...

There are different ways to add haptic input during walking which may affect walking balance. This study compared the use of two different haptic tools (rigid railing and haptic anchors) and investigated whether any effects on walking were the result of the added sensory input and/or the posture generated when using those tools. Data from 28 young healthy adults were collected using the Mobility Lab inertial sensor system (APDM, Oregon, USA). Participants walked with and without both haptic tools and while pretending to use both haptic tools (placebo trials), with eyes opened and eyes closed. Using the tools or pretending to use both tools decreased normalized stride velocity (p < .001-0.008) and peak medial-lateral (ML) trunk velocity (p < .001-0.001). Normalized stride velocity was slower when actually using the railing compared to placebo railing trials (p = .006). Using the anchors resulted in lower peak ML trunk velocity than the railing (p = .002). The anchors had lower peak ML trunk velocity than placebo anchors (p < .001), but there was no difference between railing and placebo railing (p > .999). These findings highlight a difference in the type of tool used to add haptic input and suggest that changes in balance control strategy resulting from using the railing are based on arm placement, where it is the posture combined with added sensory input that affects balance control strategies with the haptic anchors. These findings provide a strong framework for additional research to be conducted on the effects of haptic input on walking in populations known to have decreased walking balance.