A device for assisting a wearer in rotationally moving an ankle joint. A drive mechanism coaxially rotates with the ankle joint using a drive motor； a control device controls the drive motor. A storage stores a basic movement pattern and a corrected movement pattern that represent time-series changes in ankle joint angle in a gait cycled. A calculator obtains the corrected movement pattern by correcting the basic movement pattern based on input operation. The basic movement pattern is represented by a polygonal line or a Bezier curve, each of which includes a plurality of predetermined points serving as inflection points, or a combination of thereof. The calculator generates the corrected movement pattern corrected by adjusting positions of the plurality of predetermined points on the basic movement pattern, and, based on the corrected movement pattern, the control device controls driving provided by the drive motor.
