Control of plantar height by an MR fluid brake for fall prevention of patients with walking disabilities

抄録

Falls in people with walking disabilities lead to being bedridden and an increase in long term care. The prevention of these incidents is thus a key factor in maintaining activity level and maximizing their quality of life (QOL). One of the main causes of these incidents is hip fracture by sideways fall. Although the sagittal plane motion has been widely studied, there are few studies about frontal plane motion. In this study, we focus on frontal plane motion and consider fall prevention by plantar height. Falls may occur when the center of gravity (COG), which is followed by the ground reaction force, is shifted from the base of support. The focus of this study is to utilize insole treatment used in physiotherapy, which adjusts the plantar height to change the direction of the ground reaction force so as to maintain balance during walking. The purpose of this paper is to assess the effect of plantar height by magnetorheological (MR) fluid brake on fall prevention. We proposed a theoretical model combining a self-righting doll and an inverted pendulum. The model’s validity was verified by comparison with the motion of a developed leg foot model. This paper indicates the motion of the leg foot model is close to the simulation in which the model changes from the self-righting doll to the inverted pendulum. Moreover, the plantar height on the outside of the foot is effective in fall prevention because the direction of the torque changes in the opposite direction to the fall by switching to the inverted pendulum model.