Blind and Sighted Individuals

sapopulation ages, elderly people increasingly fall and injure themselves. Such falls make them hesitant to move actively and thus severely decrease their independence and quality of life. Preventing falls is therefore critical in maintaining the wellness of elderly people. In physiotherapy, a tracking task for an ankle-joint exercise can be used to facilitate motor learning of the ankle. For such tasks, a physiotherapist teaches a movement pattern that is optimally designed for the patient (reference), and the patient practices the pattern (tracking). However, Masaki Iguchi, our physiotherapist researcher (the second author) suggests that in practice such tasks tend to bore patients, who as a result may discontinue rehabilitation. Making the task effective, yet enjoyable would therefore encourage better exercise participation, resulting in fall prevention over the long term. Biofeedback has been successfully used in physical rehabilitation for approximately 40 years, but visual biofeedback (VBF) examples greatly outnumber auditory biofeedback (ABF) examples. Earlier work examined the effectiveness of VBF in a tracking task using realtime visualization of ankle-joint movement, however, the effectiveness of ABF in an anklejoint tracking task has not been investigated. Because ABF does not require visual attention, it provides a much broader possible range of postures and gestures than VBF. Unattended use of vision is beneficial in physical exercise such as gait training. Therefore ABF can overcome some drawbacks of VBF in rehabilitation. In addition to such physical advantages, ABF can widen the user population because visually impaired and blind individuals can benefit greatly from such a system. Furthermore, since music can encourage accurate motor activities with positive emotional effects in physical therapy, we expect similar effects by introducing a sonic interaction with rhythmic and melodic aspects. To address this issue, we developed a wearable auditory-biofeedback device called GaitEcho that can be used in fall prevention programs for sighted and blind individuals and examined the effects of interactive sonification on an ankle-joint exercise. This study discusses the feasibility of a reference-tracking task of ankle-joint exercise with interactive sonification for sighted and blind individuals in terms of both objective and subjective evaluations via our wearable auditory biofeedback device using the instrumented ankle-foot orthosis (AFO) we call GaitEcho. Our experimental results suggest it offers similarly adequate functionality for both blind and sighted participants.