Patent ID: 8870801

Claim:
A lower-limb joint orthosis including a lower component that supports the foot region, an upper component configured to be attached to the lower-limb, and an orthotic joint that couples the lower component and the upper component together at a position corresponding to the ankle joint so as to be bendable and stretchable in an up-down direction of the body, the orthotic joint comprising: a stator including a plurality of fluid chambers which have fan shapes formed by partitioning a short cylindrical enclosed space in a circumferential direction and in which an MR fluid whose viscosity changes depending on a magnetic force is enclosed; and a rotor including partition plates protruding from a shaft section into the respective fluid chambers so as to each secure an anterior chamber anterior to, and a posterior chamber posterior to, the partition plate, the shaft section set at a position of the orthotic joint and rotatably supported in the stator, wherein the stator includes a communication path positioned away from the fluid chambers, that allows communication between the anterior chamber and the posterior chamber of a particular one of the fluid chambers, the rotor includes, in the shaft section, connection paths that connect the anterior chambers of the respective fluid chambers together, and connect the posterior chambers of the respective fluid chambers together, and an electromagnet is placed on a side surface of the communication path so that a rotational resistance of the lower component and the upper component is adjusted by adjusting a magnetic force based on power to be supplied to the electromagnet to control the viscosity of the MR fluid that flows through the communication path.