Lower Limb Motion Measurements During Walking by Setting Rotation Angle and Period of the Motor for Driving the Chest Pad of a Rollator

The number of bedridden elderly people with stroke has rapidly increased in recent years, especially in Japan. Individuals with compromised lower limb strength due to aging or illness are encouraged to walk independently. To enhance the functionality of walking assistance, we developed a rollator with a motor-driven support chest pad in previous studies. However, the control parameters of the motor were determined based on experience. In this study, we investigated how the rotation angle and period of motor control parameters affect lower limb motion during walking. Measurements were conducted using a rollator with a motor-driven chest pad under various parameter conditions. Pressing force on the chest pad caused by walker’s upper body was measured by four force sensors, and lower limb motion, including knee flexion and ankle joint rotation, was collected using goniometers during walking measurements. The time-series data and spectral analysis results revealed distinct characteristics in lower limb movement under different control parameter conditions of the motor-driven support pad. The obtained results demonstrated that the rotational frequency of the chest pad significantly influenced lower limb movement across almost all conditions of the rotation angle.