Development of a Computer-assisted Foot Pressure Biofeedback Sensory Compensation System in Balance Control for Amputees

Sub-sensory electrical or mechanical stimulation can enhance the sensitivity of the human somatosensory system to improve the balance control capabilities of elderly was shown in recent rehabilitation articles. In addition, clinical studies suggest that visual-auditory biofeedback can improve sensory compensation for the elderly were reported. A computerized foot pressure biofeedback sensory compensation system using sub-threshold low-level electrical stimulation combined with visual-auditory biofeedback was developed and proposed for clinical study. Three unilateral trans-tibial amputees who consecutively wore prosthetics over 10 years (13plusmn3.6) were recruited in this study. Experimental results show that reduction in all of the postural sway indices (constant time sway length, max sway distance and average sway distance) and increase in single leg support time index during single leg quiet standing by applying sub-sensory stimulation. With visual-auditory biofeedback for providing clue for heel contact and toe push off condition during treadmill ambulation, the improvement of all four dynamic gait performance indices (double support time, stance/swing time ratio, constant time cadence , and sound side single support time index) in amputees was verified.