Perception of gait motion during multiple lower-limb vibrations in young healthy individuals: a pilot study

In virtual reality (VR), immersion can be created through synchronous visuomotor stimulations and enhanced by adding auditory or kinesthetic stimulations. Multiple patterned vibrations applied at the lower limbs might be a way to induce kinesthetic perception of gait motion that could be combined with VR stimulations to add the perception of self-motion. However, gait motion perception using multiple vibrations has not yet been evaluated. The objective of the study was to quantify the perception of gait motion while applying multiple, patterned vibrations to the lower limbs in healthy individuals. Twenty young healthy participants (25.1 ± 4.4 years) experienced multiple vibrations in 1-min trials. Stimulation consisted of a vibration pattern based on the sequence of muscle lengthening during a 2-s gait cycle. Stimulation was applied on participants in a standing position, under 11 experimental conditions controlling visual information (eyes open/closed), vibration frequency (40-80 Hz), and number and location of the joints stimulated (hips, knees, ankles isolated or combined two by two). Perception of gait motion was quantified for each condition using a 10-point visual analog scale (VAS, 0: "no perception", 10: "Perception of gait movements"). All participants except one achieved a score higher than 5/10 in at least one condition. Great variability was found for perception of gait motion within participants and conditions (VAS ranging from 0 to 9.6/10). Differences were found between conditions (p < 0.01), with higher mean and median scores in conditions that included knee vibration. Inducing gait motion perception is possible using multiple vibrations in healthy individuals. Stimulation of the knees seems to positively influence perception of gait motion.