Effect of Moving Tactile Stimuli to Mimic Altered Weight Distribution During Gait on Quiet Stance Body Sway

Abstract

Our purpose in the present study was to examine whether moving tactile stimuli to the sole to mimic moving weight distribution over the feet during gait would influence body sway in quiet stance. Fifteen healthy males maintained the quiet stance, and we delivered moving tactile stimuli to mimic the change in their weight distribution during gait. Moving tactile stimuli did not change the length of the center of pressure (COP) displacement and COP position. Vision decreased the length of the COP, but it did not interact with moving tactile stimuli for the COP length and position. The COP position rhythmically moved in the medial-lateral axis along with the cycle of moving tactile stimuli. The COP was at the lateral peak position at the period at which moving tactile stimuli mimicked the weight distribution in the transition between the swing and stance phases of the gait cycle. This finding may indicate that the body is positioned at the lateral peak position in quiet stance when people perceive the sensation of weight distribution over the feet at the most unstable phase of the gait cycle. We suggest that moving tactile stimuli to the sole may induce medial-lateral body sway before gait initiation for patients with Parkinson’s disease to improve their freezing of gait initiation.

Short-Term Reproduction of Active Movement with Visual Feedback and Passive Movement with a Therapist’s Hands

“…We chose only male participants because the therapist in this study was male, and we sought to minimize arousing sexual reactions to pelvic touch in cross-sex patient–therapist interactions. Our sample size was based on sample sizes in previous studies that found a significant effect of vision or tactile sensation on body sway during a quiet stance [ 12 ] ( n = 16) and found a significant difference in the reproduction of active and passive movements [ 8 ] ( n = 16). According to the number of the participants in those previous studies, we considered that 16 participants were sufficient to detect the significant difference in the reproduction error of the active and passive pelvis movement instructions in stance.…”