Using a Vibrotactile Biofeedback Device to Augment Foot Pressure During Walking in Healthy Older Adults: A Brief Report

Abstract

Human movement based on sensory control is significant to motor task performance. Thus, impairments to sensory input significantly limit feedback-type motor control. The present study introduces a vibrotactile biofeedback (BF) system which augments information regarding the user's foot pressure to enhance gait performance. The effects of the proposed system on the gait patterns of healthy older adults and on the cognitive load during gait were evaluated; these factors are essential to clarify feasibility of the device in real-life settings. The primary task of our study was to evaluate gait along with a cognitively demanding activity in 10 healthy older adults. Regarding kinematic and kinetic data in the BF condition, the subjects had significantly increased ankle dorsiflexion during the heel contact phase in the sagittal plane and marginally increased foot pressure at the toe-off and stride length. However, such kinematic and kinetic changes were not attributed to the increased walking speed. In addition, cognitive performance (i.e., the number of correct answers) was significantly decreased in participants during gait measurements in the BF condition. These data suggest that the system had the potential for modifying the kinematic and kinetic patterns during walking but not the more comprehensive walking performance in older adults. Moreover, the device appears to place a cognitive load on older adults. This short report provides crucial primary data that would help in designing successful sensory augmentation devices and further research on a BF system.

Keywords: dual task; gait training; human-machine interface; older; sensory augmentation.

FIGURE 1

System overview. (A) Our devices consist of a shoe insole with a foot pressure sensor, vibrotactile BF device (pelvic belt), and personal computer. The system augments the foot pressure pattern by using the vibratory belt attached to the pelvis. By using the feedback information, our system provides the user with accurate information regarding their gait pattern. (B) Vibrators are placed on the anterior and posterior-superior iliac spines to easily understand the tactile stimuli. During gait training, the vibrators on the trainee’s pelvic belts are simultaneously activated corresponding to the user’s foot presser sensor. (C) The sensing unit includes two built-in pressure sensors, and the sensor placement is designed to easily understand heel strike and push off. Using this information from insole sensors, the user can be aware of the timing, and intensity of their heel strike and push off.