a first brace configured to be worn on at least a waist of a user;

an arm configured to extend along a thigh of the user and to rotate with respect to the first brace;

an actuator configured to generate torque that rotates the arm; and

a second brace provided on the arm and configured to be worn on the thigh, wherein

the arm includes an arm body and a holding portion, the holding portion being provided on the arm body such that the holding portion is movable in a longitudinal direction of the arm body, and the holding portion holding the second brace such that the second brace is rotatable,

the second brace includes a pad having a plate shape,

the arm body includes a guide rail extending in the longitudinal direction of the arm body,

the holding portion includes a moving block, a base member, and a pad support portion, the moving block being configured to run on the guide rail in the longitudinal direction of the arm body, the base member being fixed to the moving block and including a base surface extending in the longitudinal direction, and the pad support portion supporting the pad such that the pad is rotatable with the pad facing the base surface,

the pad has a slit extending in a circumferential direction about a rotation center of the second brace, and

the holding portion further includes a pin member protruding from the base surface and inserted in the slit.